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"Butler, Rachel"
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Prevalence of long-term decision regret and associated risk factors in a large cohort of ICU surrogate decision makers
2023
Background
Whether surrogate decision makers regret decisions about the use of life support for incapacitated, critically ill patients remain uncertain. We sought to determine the prevalence of decision regret among surrogates of adult ICU patients and identify factors that influence regret.
Methods
We conducted a secondary analysis of data from the PARTNER 2 trial, which tested a family support intervention for surrogates of critically ill adults. At 6-month follow-up, surrogates rated their regret about life support decisions using the Decision Regret Scale (DRS), scored from 0 to 100, with higher scores indicating more regret. We used multiple linear regression to identify covariates associated with decision regret based on a psychological construct of regret. We constructed two models using the full cohort; model 1 included patient outcomes; model 2 focused on covariates known at the time of ICU decision-making. Subgroup analyses were also conducted based on patient survival status at hospital discharge and 6-month follow-up.
Results
748 of 848 surrogates had complete DRS data. The median (IQR) DRS score was 15 (0, 25). Overall, 54% reported mild regret (DRS 5–25), 19% moderate-strong regret (DRS 30–100), and 27% no regret (DRS 0). Poor patient outcome at 6 months (death or severe functional dependence) was associated with more regret in model 1 (β 10.1; 95% C.I. 3.2, 17.0). In model 2, palliative care consultation (3.0; 0.1, 5.9), limitations in life support (LS) prior to death (6.3; 3.1, 9.4) and surrogate black race (6.3; 0.3, 12.3) were associated with more regret. Other modulators of regret in subgroup analyses included surrogate age and education level, surrogate-patient relationship, death in hospital (compared to the post-discharge period), and code status at time of ICU admission.
Conclusions
One in five ICU surrogate decision makers experience moderate to strong regret about life support decisions in ICU. Poor patient outcomes are linked to more regret. Decisions to limit life support prior to patient death may also increase regret. Future studies are needed to understand how regret relates to decision quality and how to lessen lasting regret.
Journal Article
Molecular basis for DarT ADP-ribosylation of a DNA base
by
Tromans-Coia, Callum
,
Goh, Shan
,
Schuller, Marion
in
631/326/421
,
631/337/1427
,
631/45/607/1159
2021
ADP-ribosyltransferases use NAD
+
to catalyse substrate ADP-ribosylation
1
, and thereby regulate cellular pathways or contribute to toxin-mediated pathogenicity of bacteria
2
–
4
. Reversible ADP-ribosylation has traditionally been considered a protein-specific modification
5
, but recent in vitro studies have suggested nucleic acids as targets
6
–
9
. Here we present evidence that specific, reversible ADP-ribosylation of DNA on thymidine bases occurs in cellulo through the DarT–DarG toxin–antitoxin system, which is found in a variety of bacteria (including global pathogens such as
Mycobacterium tuberculosis
, enteropathogenic
Escherichia coli
and
Pseudomonas aeruginosa
)
10
. We report the structure of DarT, which identifies this protein as a diverged member of the PARP family. We provide a set of high-resolution structures of this enzyme in ligand-free and pre- and post-reaction states, which reveals a specialized mechanism of catalysis that includes a key active-site arginine that extends the canonical ADP-ribosyltransferase toolkit. Comparison with PARP–HPF1, a well-established DNA repair protein ADP-ribosylation complex, offers insights into how the DarT class of ADP-ribosyltransferases evolved into specific DNA-modifying enzymes. Together, our structural and mechanistic data provide details of this PARP family member and contribute to a fundamental understanding of the ADP-ribosylation of nucleic acids. We also show that thymine-linked ADP-ribose DNA adducts reversed by DarG antitoxin (functioning as a noncanonical DNA repair factor) are used not only for targeted DNA damage to induce toxicity, but also as a signalling strategy for cellular processes. Using
M. tuberculosis
as an exemplar, we show that DarT–DarG regulates growth by ADP-ribosylation of DNA at the origin of chromosome replication.
Structural and mechanistic data of the ADP-ribosyltransferase DarT demonstrate the role of ADP-ribosylation of DNA by this enzyme in generating toxicity and regulating cellular signalling processes in bacteria.
Journal Article
Fulvestrant plus capivasertib versus placebo after relapse or progression on an aromatase inhibitor in metastatic, oestrogen receptor-positive, HER2-negative breast cancer (FAKTION): overall survival, updated progression-free survival, and expanded biomarker analysis from a randomised, phase 2 trial
by
Meissner, Magdalena
,
Howell, Sacha J
,
Jones, Robert H
in
1-Phosphatidylinositol 3-kinase
,
Adolescent
,
Adult
2022
Capivasertib, an AKT inhibitor, added to fulvestrant, was previously reported to improve progression-free survival in women with aromatase inhibitor-resistant oestrogen receptor (ER)-positive, HER2-negative advanced breast cancer. The benefit appeared to be independent of the phosphoinositide 3-kinase (PI3K)/AKT/phosphatase and tensin homologue (PTEN) pathway alteration status of tumours, as ascertained using assays available at the time. Here, we report updated progression-free survival and overall survival results, and a prespecified examination of the effect of PI3K/AKT/PTEN pathway alterations identified by an expanded genetic testing panel on treatment outcomes.
This randomised, multicentre, double-blind, placebo-controlled, phase 2 trial recruited postmenopausal adult women aged at least 18 years with ER-positive, HER2-negative, metastatic or locally advanced inoperable breast cancer and an Eastern Cooperative Oncology Group performance status of 0–2, who had relapsed or progressed on an aromatase inhibitor, from across 19 hospitals in the UK. Participants were randomly assigned (1:1) to receive intramuscular fulvestrant 500 mg (day 1) every 28 days (plus a 500 mg loading dose on day 15 of cycle 1) with either capivasertib 400 mg or matching placebo, orally twice daily on an intermittent weekly schedule of 4 days on and 3 days off, starting on cycle 1 day 15. Treatment continued until disease progression, unacceptable toxicity, loss to follow-up, or withdrawal of consent. Treatment was allocated by an interactive web-response system using a minimisation method (with a 20% random element) and the following minimisation factors: measurable or non-measurable disease, primary or secondary aromatase inhibitor resistance, PIK3CA status, and PTEN status. The primary endpoint was progression-free survival in the intention-to-treat population. Secondary endpoints shown in this Article were overall survival and safety in the intention-to-treat population, and the effect of tumour PI3K/AKT/PTEN pathway status identified by an expanded testing panel that included next-generation sequencing assays. Recruitment is complete. The trial is registered with ClinicalTrials.gov, number NCT01992952.
Between March 16, 2015, and March 6, 2018, 183 participants were screened for eligibility and 140 (77%) were randomly assigned to receive fulvestrant plus capivasertib (n=69) or fulvestrant plus placebo (n=71). Median follow-up at the data cut-off of Nov 25, 2021, was 58·5 months (IQR 45·9–64·1) for participants treated with fulvestrant plus capivasertib and 62·3 months (IQR 62·1–70·3) for fulvestrant plus placebo. Updated median progression-free survival was 10·3 months (95% CI 5·0–13·4) in the group receiving fulvestrant plus capivasertib compared with 4·8 months (3·1–7·9) for fulvestrant plus placebo (adjusted hazard ratio [HR] 0·56 [95% CI 0·38–0·81]; two-sided p=0·0023). Median overall survival in the capivasertib versus placebo groups was 29·3 months (95% CI 23·7–39·0) versus 23·4 months (18·7–32·7; adjusted HR 0·66 [95% CI 0·45–0·97]; two-sided p=0·035). The expanded biomarker panel identified an expanded pathway-altered subgroup that contained 76 participants (54% of the intention-to-treat population). Median progression-free survival in the expanded pathway-altered subgroup for participants receiving capivasertib (n=39) was 12·8 months (95% CI 6·6–18·8) compared with 4·6 months (2·8–7·9) in the placebo group (n=37; adjusted HR 0·44 [95% CI 0·26–0·72]; two-sided p=0·0014). Median overall survival for the expanded pathway-altered subgroup receiving capivasertib was 38·9 months (95% CI 23·3–50·7) compared with 20·0 months (14·8–31·4) for those receiving placebo (adjusted HR 0·46 [95% CI 0·27–0·79]; two-sided p=0·0047). By contrast, there were no statistically significant differences in progression-free or overall survival in the expanded pathway non-altered subgroup treated with capivasertib (n=30) versus placebo (n=34). One additional serious adverse event (pneumonia) in the capivasertib group had occurred subsequent to the primary analysis. One death, due to atypical pulmonary infection, was assessed as possibly related to capivasertib treatment.
Updated FAKTION data showed that capivasertib addition to fulvestrant extends the survival of participants with aromatase inhibitor-resistant ER-positive, HER2-negative advanced breast cancer. The expanded biomarker testing suggested that capivasertib predominantly benefits patients with PI3K/AKT/PTEN pathway-altered tumours. Phase 3 data are needed to substantiate the results, including in patients with previous CDK4/6 inhibitor exposure who were not included in the FAKTION trial.
AstraZeneca and Cancer Research UK.
Journal Article
Fulvestrant plus capivasertib versus placebo after relapse or progression on an aromatase inhibitor in metastatic, oestrogen receptor-positive breast cancer (FAKTION): a multicentre, randomised, controlled, phase 2 trial
2020
Capivasertib (AZD5363) is a potent selective oral inhibitor of all three isoforms of the serine/threonine kinase AKT. The FAKTION trial investigated whether the addition of capivasertib to fulvestrant improved progression-free survival in patients with aromatase inhibitor-resistant advanced breast cancer.
In this randomised, double-blind, placebo-controlled, phase 2 trial, postmenopausal women aged at least 18 years with an Eastern Cooperative Oncology Group performance status of 0–2 and oestrogen receptor-positive, HER2-negative, metastatic or locally advanced inoperable breast cancer who had relapsed or progressed on an aromatase inhibitor were recruited from 19 hospitals in the UK. Enrolled participants were randomly assigned (1:1) to receive intramuscular fulvestrant 500 mg (day 1) every 28 days (plus a loading dose on day 15 of cycle 1) with either capivasertib 400 mg or matching placebo, orally twice daily on an intermittent weekly schedule of 4 days on and 3 days off (starting on cycle 1 day 15) until disease progression, unacceptable toxicity, loss to follow-up, or withdrawal of consent. Treatment allocation was done using an interactive web-response system using a minimisation method (with a 20% random element) and the following minimisation factors: measurable or non-measurable disease, primary or secondary aromatase inhibitor resistance, PIK3CA status, and PTEN status. The primary endpoint was progression-free survival with a one-sided alpha of 0·20. Analyses were done by intention to treat. Recruitment is complete, and the trial is in follow-up. This trial is registered with ClinicalTrials.gov, number NCT01992952.
Between March 16, 2015, and March 6, 2018, 183 patients were screened for eligibility, of whom 140 (76%) were eligible and were randomly assigned to receive fulvestrant plus capivasertib (n=69) or fulvestrant plus placebo (n=71). Median follow-up for progression-free survival was 4·9 months (IQR 1·6–11·6). At the time of primary analysis for progression-free survival (Jan 30, 2019), 112 progression-free survival events had occurred, 49 (71%) in 69 patients in the capivasertib group compared with 63 (89%) of 71 in the placebo group. Median progression-free survival was 10·3 months (95% CI 5·0–13·2) in the capivasertib group versus 4·8 months (3·1–7·7) in the placebo group, giving an unadjusted hazard ratio (HR) of 0·58 (95% CI 0·39–0·84) in favour of the capivasertib group (two-sided p=0·0044; one-sided log rank test p=0·0018). The most common grade 3–4 adverse events were hypertension (22 [32%] of 69 patients in the capivasertib group vs 17 [24%] of 71 in the placebo group), diarrhoea (ten [14%] vs three [4%]), rash (14 [20%] vs 0), infection (four [6%] vs two [3%]), and fatigue (one [1%] vs three [4%]). Serious adverse reactions occurred only in the capivasertib group, and were acute kidney injury (two), diarrhoea (three), rash (two), hyperglycaemia (one), loss of consciousness (one), sepsis (one), and vomiting (one). One death, due to atypical pulmonary infection, was assessed as possibly related to capivasertib treatment. One further death in the capivasertib group had an unknown cause; all remaining deaths in both groups (19 in the capivasertib group and 31 in the placebo group) were disease related.
Progression-free survival was significantly longer in participants who received capivasertib than in those who received placebo. The combination of capivasertib and fulvestrant warrants further investigation in phase 3 trials.
AstraZeneca and Cancer Research UK.
Journal Article
The Relationship Between Body Mass Index, Implicit Weight Bias, and Social Anxiety in Undergraduate Women
2023
BackgroundPeer victimization is linked to social anxiety (SA), and rates of bullying are significantly higher for individuals at higher weights. However, research has yet to examine whether implicit weight bias exacerbates this link.MethodsThis study examined the relationships between body mass index (BMI), SA, and implicit weight bias in undergraduate women (N = 186; 54.8% White; MBMI = 25.97). Participants completed questionnaires pertaining to SA, stigmatizing attitudes toward weight, and two implicit association tests (IATs) used to measure anti-fat attitudes. IATs required categorization of words into attribute category pairs good vs. bad and motivated vs. lazy.ResultsBMI and SA were not significantly related. Implicit weight bias assessed by the good/bad IAT moderated the relationship between BMI and SA. Implicit weight bias assessed by the lazy/motivated IAT moderated the relationship between BMI and SA at the trend level (p = .06). Higher BMI was associated with higher SA in individuals with high, but not low, implicit weight bias. Implicit weight bias was associated with internalization of the thin ideal but not explicit weight bias.ConclusionsTherapeutic interventions for SA among individuals with high BMI should explore internalized weight stigma, which may take the form of implicit attitudes or beliefs.
Journal Article
Reversal of end-stage retinal degeneration and restoration of visual function by photoreceptor transplantation
by
Martin, Chris
,
Lipinski, Daniel M.
,
Singh, Mandeep S.
in
animal models
,
Animals
,
Biological and medical sciences
2013
One strategy to restore vision in retinitis pigmentosa and agerelated macular degeneration is cell replacement. Typically, patients lose vision when the outer retinal photoreceptor layer is lost, and so the therapeutic goal would be to restore vision at this stage of disease. It is not currently known if a degenerate retina lacking the outer nuclear layer of photoreceptor cells would allow the survival, maturation, and reconnection of replacement photoreceptors, as prior studies used hosts with a preexisting outer nuclear layer at the time of treatment. Here, using a murine model of severe human retinitis pigmentosa at a stage when no host rod cells remain, we show that transplanted rod precursors can reform an anatomically distinct and appropriately polarized outer nuclear layer. A trilaminar organization was returned to rd1 hosts that had only two retinal layers before treatment. The newly introduced precursors were able to resume their developmental program in the degenerate host niche to become mature rods with light-sensitive outer segments, reconnecting with host neurons downstream. Visual function, assayed in the same animals before and after transplantation, was restored in animals with zero rod function at baseline. These observations suggest that a cell therapy approach may reconstitute a light-sensitive cell layer de novo and hence repair a structurally damaged visual circuit. Rather than placing discrete photoreceptors among preexisting host outer retinal cells, total photoreceptor layer reconstruction may provide a clinically relevant model to investigate cell-based strategies for retinal repair.
Journal Article
Systemic chemotherapy with or without cetuximab in patients with resectable colorectal liver metastasis: the New EPOC randomised controlled trial
by
Little, Louisa
,
Bridgewater, John
,
Maughan, Tim
in
Aged
,
Antibodies, Monoclonal, Humanized - administration & dosage
,
Antibodies, Monoclonal, Humanized - therapeutic use
2014
Surgery for colorectal liver metastases results in an overall survival of about 40% at 5 years. Progression-free survival is increased with the addition of oxaliplatin and fluorouracil chemotherapy. The addition of cetuximab to these chemotherapy regimens results in an overall survival advantage in patients with advanced disease who have the KRAS exon 2 wild-type tumour genotype. We aimed to assess the benefit of addition of cetuximab to standard chemotherapy in patients with resectable colorectal liver metastasis.
Patients with KRAS exon 2 wild-type resectable or suboptimally resectable colorectal liver metastases were randomised in a 1:1 ratio to receive chemotherapy with or without cetuximab before and after liver resection. Randomisation was done using minimisation with factors of surgical centre, poor prognostic tumour (one or more of: ≥4 metastases, N2 disease, or poor differentiation of primary tumour), and previous adjuvant treatment with oxaliplatin. Chemotherapy consisted of oxaliplatin 85 mg/m2 intravenously over 2 h and fluorouracil bolus 400 mg/m2 intravenously over 5 min, followed by a 46 h infusion of fluorouracil 2400 mg/m2 repeated every 2 weeks (regimen one) or oxaliplatin 130 mg/m2 intravenously over 2 h and oral capecitabine 1000 mg/m2 twice daily on days 1–14 repeated every 3 weeks (regimen two). Patients who had received adjuvant oxaliplatin could receive irinotecan 180 mg/m2 intravenously over 30 min with fluorouracil instead of oxaliplatin (regimen three). Cetuximab was given as an intravenous dose of 500 mg/m2 every 2 weeks with regimen one and three or a loading dose of 400 mg/m2 followed by a weekly infusion of 250 mg/m2 with regimen two. The primary endpoint was progression-free survival. This is an interim analysis, up to Nov 1, 2012, when the trial was closed, having met protocol-defined futility criteria. This trial is registered, ISRCTN22944367.
128 KRAS exon 2 wild-type patients were randomised to chemotherapy alone and 129 to chemotherapy with cetuximab between Feb 26, 2007, and Nov 1, 2012. 117 patients in the chemotherapy alone group and 119 in the chemotherapy plus cetuximab group were included in the primary analysis. The median follow-up was 21·1 months (95% CI 12·6–33·8) in the chemotherapy alone group and 19·8 months (12·2–28·7) in the chemotherapy plus cetuximab group. With an overall median follow-up of 20·7 months (95% CI 17·9–25·6) and 123 (58%) of 212 required events observed, progression-free survival was significantly shorter in the chemotherapy plus cetuximab group than in the chemotherapy alone group (14·1 months [95% CI 11·8–15·9] vs 20·5 months [95% CI 16·8–26·7], hazard ratio 1·48, 95% CI 1·04–2·12, p=0·030). The most common grade 3 or 4 adverse events were low neutrophil count (15 [11%] preoperatively in the chemotherapy alone group vs six [4%] in the chemotherapy plus cetuximab group; four [4%] vs eight [8%] postoperatively), embolic events (six [4%] vs eight [6%] preoperatively; two [2%] vs three [3%] postoperatively), peripheral neuropathy (six [4%] vs one [1%] preoperatively; two [2%] vs four [4%] postoperatively), nausea or vomiting (four [3%] vs six [4%] preoperatively; four [4%] vs two [2%] postoperatively), and skin rash (two [1%] vs 21 [15%] preoperatively; 0 vs eight [8%] postoperatively). There were three deaths in the chemotherapy plus cetuximab group (one interstitial lung disease and pulmonary embolism, one bronchopneumonia, and one pulmonary embolism) and one in the chemotherapy alone group (heart failure) that might have been treatment related.
Addition of cetuximab to chemotherapy and surgery for operable colorectal liver metastases in KRAS exon 2 wild-type patients results in shorter progression-free survival. Translational investigations to explore the molecular basis for this unexpected interaction are needed but at present the use of cetuximab in this setting cannot be recommended.
Cancer Research UK.
Journal Article
The Balance of Apoptotic and Necrotic Cell Death in Mycobacterium tuberculosis Infected Macrophages Is Not Dependent on Bacterial Virulence
2012
An important mechanism of Mycobacterium tuberculosis pathogenesis is the ability to control cell death pathways in infected macrophages: apoptotic cell death is bactericidal, whereas necrotic cell death may facilitate bacterial dissemination and transmission.
We examine M.tuberculosis control of spontaneous and chemically induced macrophage cell death using automated confocal fluorescence microscopy, image analysis, flow cytometry, plate-reader based vitality assays, and M.tuberculosis strains including H37Rv, and isogenic virulent and avirulent strains of the Beijing lineage isolate GC1237.
We show that bacterial virulence influences the dynamics of caspase activation and the total level of cytotoxicity. We show that the powerful ability of M.tuberculosis to inhibit exogenously stimulated apoptosis is abrogated by loss of virulence. However, loss of virulence did not influence the balance of macrophage apoptosis and necrosis--both virulent and avirulent isogenic strains of GC1237 induced predominantly necrotic cell death compared to H37Rv which induced a higher relative level of apoptosis.
This reveals that macrophage necrosis and apoptosis are independently regulated during M. tuberculosis infection of macrophages. Virulence affects the level of host cell death and ability to inhibit apoptosis but other strain-specific characteristics influence the ultimate mode of host cell death and alter the balance of apoptosis and necrosis.
Journal Article
Histone deacetylase inhibitors as therapeutics for polyglutamine disorders
2006
Key Points
Transcriptional dysregulation is part of the pathogenic mechanism that underlies neuronal dysfunction in polyglutamine repeat diseases such as Huntington's disease (HD). Microarray experiments show that the expression of a subset of genes is robustly altered in mouse models of HD and in the brains of patients with HD.
Histone acetyltransferases (HATs) and histone deacetylases (HDACs) are enzymes that control transcription by acetylating and deacetylating histones, thereby changing the conformation of chromatin structure.
Expanded polyglutamine repeat proteins adopt aberrant interactions with HATs and HDACs as well as other transcription factors, co-activators and co-repressors owing to conformational changes caused by the polyglutamine stretch within the mutant protein.
Of the four classes of HDAC enzyme, class I is ubiquitously expressed and class II is highly expressed in muscle, heart and brain.
In addition to deacetylating histones, HDACs also modify non-histone proteins such as the tumour suppressor p53 and heat shock protein 90 (HSP90), both of which are implicated in HD pathogenesis.
Compounds that inhibit these class I and II HDACs are in clinical trials for the treatment of many types of cancer. These drugs are currently being tested in preclinical trials using mouse models of polyglutamine repeat disease.
One HDAC inhibitor, phenylbutyrate, is in phase II clinical trials for HD, and alterations in blood biomarker expression after treatment look promising.
An important pathological feature of polyglutamine repeat diseases involves abnormal interactions between the mutant protein and histone-modifying enzymes, leading to transcriptional dysregulation. Inhibition of these enzymes is therefore a promising therapeutic strategy for Huntington's disease and other polyglutamine repeat disorders.
During the past 5 years, gene expression studies in cell culture, animal models and in the brains of patients have shown that the perturbation of transcription frequently results in neuronal dysfunction in polyglutamine repeat diseases such as Huntington's disease. Histone deacetylases act as repressors of transcription through interactions with co-repressor complexes, which leads to chromatin remodelling. Aberrant interactions between polyglutamine proteins and regulators of transcription could be one mechanism by which transcriptional dysregulation occurs. Here, we discuss the potential therapeutic pathways through which histone deacetylase inhibitors might act to correct the aberrant transcription observed in Huntington's disease and other polyglutamine repeat diseases.
Journal Article
Caught at the surface
by
Stewart, Joshua D.
,
Butler, Rachel H.
,
Barroso, Alfredo
in
Animals
,
Aquatic mammals
,
Dolphins
2018
Journal Article