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1.
Transfusion ; 63(3): 541-551, 2023 03.
Article in English | MEDLINE | ID: mdl-36794597

ABSTRACT

BACKGROUND: Deferrals due to low hemoglobin are time-consuming and costly for blood donors and donation services. Furthermore, accepting donations from those with low hemoglobin could represent a significant safety issue. One approach to reduce them is to use hemoglobin concentration alongside donor characteristics to inform personalized inter-donation intervals. STUDY DESIGN AND METHODS: We used data from 17,308 donors to inform a discrete event simulation model comparing personalized inter-donation intervals using "post-donation" testing (i.e., estimating current hemoglobin from that measured by a hematology analyzer at last donation) versus the current approach in England (i.e., pre-donation testing with fixed intervals of 12-weeks for men and 16-weeks for women). We reported the impact on total donations, low hemoglobin deferrals, inappropriate bleeds, and blood service costs. Personalized inter-donation intervals were defined using mixed-effects modeling to estimate hemoglobin trajectories and probability of crossing hemoglobin donation thresholds. RESULTS: The model had generally good internal validation, with predicted events similar to those observed. Over 1 year, a personalized strategy requiring ≥90% probability of being over the hemoglobin threshold, minimized adverse events (low hemoglobin deferrals and inappropriate bleeds) in both sexes and costs in women. Donations per adverse event improved from 3.4 (95% uncertainty interval 2.8, 3.7) under the current strategy to 14.8 (11.6, 19.2) in women, and from 7.1 (6.1, 8.5) to 26.9 (20.8, 42.6) in men. In comparison, a strategy incorporating early returns for those with high certainty of being over the threshold maximized total donations in both men and women, but was less favorable in terms of adverse events, with 8.4 donations per adverse event in women (7.0, 10,1) and 14.8 (12.1, 21.0) in men. DISCUSSION: Personalized inter-donation intervals using post-donation testing combined with modeling of hemoglobin trajectories can help reduce deferrals, inappropriate bleeds, and costs.


Subject(s)
Blood Donation , Hemoglobins , Male , Humans , Female , Hemoglobins/analysis , England , Hematologic Tests , Blood Donors
2.
Mol Pharm ; 20(1): 341-356, 2023 01 02.
Article in English | MEDLINE | ID: mdl-36445335

ABSTRACT

Cell-impermeable and negatively charged compounds' cellular uptake across the cell membranes remains challenging. Herein, the synthesis of four linear [(WWRR)2, (WWRR)3, (WWRR)4, and (WWRR)5] and four cyclic ([WWRR]2, [WWRR]3, [WWRR]4, and [WWRR]5) peptides containing alternate two tryptophan (WW) and two arginine (RR) residues and their biological evaluation as molecular transporters are reported. The peptides did not show any significant cytotoxicity in different cell lines (MDA-MB-23, SK-OV-3, and HEK 293) at a concentration of 5 µM and after 3 h of incubation time. The uptake of fluorescence-labeled cargo molecules (F'-GpYEEI, F'-siRNA, and F'-3TC) in the presence of the peptides was monitored in different cell lines (SK-OV-3 and MDA-MB-231) with fluorescence-activated cell sorting. Among all the peptides, [WWRR]5 (C4) showed the highest cellular uptake of cargo molecules, indicating it can act as effective molecular transporter. Confocal microscopy in MDA-MB-231 cells showed the cellular uptake of F'-GpYEEI in the presence of C4 and the intracellular localization of fluorescence-labeled C4 (F'-C4) in the cytosol. The F'-C4 cellular uptake was found to be concentration- and time-dependent, as shown by flow cytometry in MDA-MB-231 cells. Confocal microscopy and flow cytometry of F'-C4 in MDA-MB-231 cells were examined alone and in the presence of different endocytosis inhibitors (chlorpromazine, methyl-ß-cyclodextrin, chloroquine, and nystatin). The data showed that the cellular uptake of F'-C4 in the presence of chlorpromazine, chloroquine, and methyl-ß-cyclodextrin was reduced but not completely eliminated, indicating that both energy-independent and energy-dependent pathways contributed to the cellular uptake of F'-C4. Similar results were obtained using the confocal microscopy of C4 and F'-GpYEEI in the presence of endocytosis inhibitors (chlorpromazine, methyl-ß-cyclodextrin, chloroquine, and nystatin). These data indicate that C4 has the potential to be used as a cell-penetrating peptide and cargo transporter.


Subject(s)
Cell-Penetrating Peptides , Peptides, Cyclic , Humans , Peptides, Cyclic/chemistry , Chlorpromazine , HEK293 Cells , Nystatin , Cell Line, Tumor , Endocytosis
3.
BJOG ; 130(12): 1521-1530, 2023 11.
Article in English | MEDLINE | ID: mdl-37156754

ABSTRACT

OBJECTIVE: To investigate the hypothesis that risk factors in addition to an abnormal fetal heart rate pattern (aFHRp) are independently associated with adverse neonatal outcomes of labour. DESIGN: Observational prospective cohort study. SETTING: 17 UK maternity units. SAMPLE: 585 291 pregnancies between 1988 and 2000 inclusive. METHODS: Adjusted odds ratios (OR) with 95% confidence intervals (95% CI) were estimated from multivariable logistic regression. MAIN OUTCOME MEASURES: Adverse neonatal outcome at term (5-minute Apgar score <7, and a composite measure comprising 5-minute Apgar score <7, resuscitation by intubation and/or perinatal death). RESULTS: Analysis was based on 302 137 vaginal births at 37-42 weeks inclusive. We found a higher odds of Apgar score at 5 minutes <7 with suspected fetal growth restriction (OR 1.34, 95% CI 1.16-1.53), induction of labour (OR 1.41, 95% CI 1.25-1.58), nulliparity (OR 1.48, 95% CI 1.34-1.63), booking body mass index ≥30 (OR 1.18, 95% CI 1.02-1.37), maternal age <25 (OR 1.23, 95% CI 1.10-1.39), black ethnicity (OR 1.21, 95% CI 1.03-1.43), early-term birth at 37-38 weeks (OR 1.13, 95% CI 1.02-1.25), late-term birth at 41-42 weeks (OR 1.14, 95% CI 1.01-1.28), use of oxytocin (OR 1.27, 95% CI 1.14-1.41), maternal pyrexia (OR 1.87, 95% CI 1.46-2.40), aFHRp and presence of meconium (aFHRp without meconium: OR 2.40, 95% CI 2.15-2.69; meconium without aFHRp: OR 2.20, 195% CI.94-2.49; both aFHRp and meconium: OR 4.26, 95% CI 3.74-4.87). The results were similar when the composite adverse outcome was considered. CONCLUSIONS: A range of risk factors, including suspicion of fetal growth restriction, maternal pyrexia and presence of meconium, are implicated in poor birth outcomes in addition to aFHRp. Interpretation of the fetal heart rate pattern alone is insufficient as a basis for decisions about escalation and intervention.


Subject(s)
Cesarean Section , Fetal Growth Retardation , Infant, Newborn , Pregnancy , Female , Humans , Retrospective Studies , Prospective Studies , Risk Factors , Fever
4.
Ann Surg ; 274(6): e589-e598, 2021 12 01.
Article in English | MEDLINE | ID: mdl-31592810

ABSTRACT

BACKGROUND: EVAR for abdominal aortic aneurysm has an initial survival advantage over OR, but more frequent complications increase costs and long-term aneurysm-related mortality. Randomized controlled trials of EVAR versus OR have shown EVAR is not cost-effective over a patient's lifetime. However, in the EVAR-1 trial, postoperative surveillance may have been sub-optimal, as the importance of sac growth as a predictor of graft failure was overlooked. METHODS: Real-world data informed a discrete event simulation model of postoperative outcomes following EVAR. Outcomes observed EVAR-1 were compared with those from 5 alternative postoperative surveillance and re-intervention strategies. Key events, quality-adjusted life years and costs were predicted. The impact of using complication and rupture rates from more recent devices, imaging and re-intervention methods was also explored. RESULTS: Compared with observed EVAR-1 outcomes, modeling full adherence to the EVAR-1 scan protocol reduced abdominal aortic aneurysm (AAA) deaths by 3% and increased elective re-interventions by 44%. European Society re-intervention guidelines provided the most clinically effective strategy, with an 8% reduction in AAA deaths, but a 52% increase in elective re-interventions. The cheapest and most cost-effective strategy used lifetime annual ultrasound in primary care with confirmatory computed tomography if necessary, and reduced AAA-related deaths by 5%. Using contemporary rates for complications and rupture did not alter these conclusions. CONCLUSIONS: All alternative strategies improved clinical benefits compared with the EVAR-1 trial. Further work is needed regarding the cost and accuracy of primary care ultrasound, and the potential impact of these strategies in the comparison with OR.


Subject(s)
Aortic Aneurysm, Abdominal/surgery , Elective Surgical Procedures/economics , Endovascular Procedures/economics , Endovascular Procedures/methods , Aortic Aneurysm, Abdominal/complications , Aortic Rupture/etiology , Computer Simulation , Cost-Benefit Analysis , Elective Surgical Procedures/adverse effects , Endovascular Procedures/adverse effects , Hospital Costs , Humans , Postoperative Complications , Quality of Life , Reoperation
5.
BMC Med ; 18(1): 95, 2020 04 17.
Article in English | MEDLINE | ID: mdl-32299423

ABSTRACT

BACKGROUND: The clinical pathway to detect and diagnose prostate cancer has been revolutionised by the use of multiparametric MRI (mpMRI pre-biopsy). mpMRI however remains a resource-intensive test and is highly operator dependent with variable effectiveness with regard to its negative predictive value. Here we tested the use of the phi assay in standard clinical practice to pre-select men at the highest risk of harbouring significant cancer and hence refine the use of mpMRI and biopsies. METHODS: A prospective five-centre study recruited men being investigated through an mpMRI-based prostate cancer diagnostic pathway. Test statistics for PSA, PSA density (PSAd) and phi were assessed for detecting significant cancers using 2 definitions: ≥ Grade Group (GG2) and ≥ Cambridge Prognostic Groups (CPG) 3. Cost modelling and decision curve analysis (DCA) was simultaneously performed. RESULTS: A total of 545 men were recruited and studied with a median age, PSA and phi of 66 years, 8.0 ng/ml and 44 respectively. Overall, ≥ GG2 and ≥ CPG3 cancer detection rates were 64% (349/545), 47% (256/545) and 32% (174/545) respectively. There was no difference across centres for patient demographics or cancer detection rates. The overall area under the curve (AUC) for predicting ≥ GG2 cancers was 0.70 for PSA and 0.82 for phi. AUCs for ≥ CPG3 cancers were 0.81 and 0.87 for PSA and phi respectively. AUC values for phi did not differ between centres suggesting reliability of the test in different diagnostic settings. Pre-referral phi cut-offs between 20 and 30 had NPVs of 0.85-0.90 for ≥ GG2 cancers and 0.94-1.0 for ≥ CPG3 cancers. A strategy of mpMRI in all and biopsy only positive lesions reduced unnecessary biopsies by 35% but missed 9% of ≥ GG2 and 5% of ≥ CPG3 cancers. Using PH ≥ 30 to rule out referrals missed 8% and 5% of ≥ GG2 and ≥ CPG3 cancers (and reduced unnecessary biopsies by 40%). This was achieved however with 25% fewer mpMRI. Pathways incorporating PSAd missed fewer cancers but necessitated more unnecessary biopsies. The phi strategy had the lowest mean costs with DCA demonstrating net clinical benefit over a range of thresholds. CONCLUSION: phi as a triaging test may be an effective way to reduce mpMRI and biopsies without compromising detection of significant prostate cancers.


Subject(s)
Costs and Cost Analysis/methods , Diagnostic Services/trends , Magnetic Resonance Imaging/methods , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/economics , Referral and Consultation/standards , Triage/methods , Aged , Humans , Male , Prospective Studies , Prostatic Neoplasms/diagnosis
6.
Am Heart J ; 203: 105-108, 2018 09.
Article in English | MEDLINE | ID: mdl-30060882

ABSTRACT

The therapeutic benefit of self-monitoring blood pressure in stroke patients is uncertain. We investigated the effect of self-monitoring with or without guided antihypertensive management compared with usual care in patients with a recent cerebrovascular event. No between-group differences in blood pressure at outcome were found, but blood pressure self-monitoring and management was well tolerated.


Subject(s)
Antihypertensive Agents/therapeutic use , Blood Pressure Monitoring, Ambulatory/methods , Blood Pressure/physiology , Hypertension/drug therapy , Ischemic Attack, Transient/physiopathology , Self-Management/methods , Stroke/physiopathology , Aged , Female , Humans , Hypertension/physiopathology , Ischemic Attack, Transient/etiology , Male , Middle Aged , Randomized Controlled Trials as Topic , Stroke/etiology
7.
Nephrol Dial Transplant ; 33(8): 1373-1379, 2018 08 01.
Article in English | MEDLINE | ID: mdl-29045728

ABSTRACT

Background: In the UK, primary care records are electronic and require doctors to ascribe disease codes to direct care plans and facilitate safe prescribing. We investigated factors associated with coding of chronic kidney disease (CKD) in patients with reduced kidney function and the impact this has on patient management. Methods: We identified patients meeting biochemical criteria for CKD (two estimated glomerular filtration rates <60 mL/min/1.73 m2 taken >90 days apart) from 1039 general practitioner (GP) practices in a UK audit. Clustered logistic regression was used to identify factors associated with coding for CKD and improvement in coding as a result of the audit process. We investigated the relationship between coding and five interventions recommended for CKD: achieving blood pressure targets, proteinuria testing, statin prescription and flu and pneumococcal vaccination. Results: Of 256 000 patients with biochemical CKD, 30% did not have a GP CKD code. Males, older patients, those with more severe CKD, diabetes or hypertension or those prescribed statins were more likely to have a CKD code. Among those with continued biochemical CKD following audit, these same characteristics increased the odds of improved coding. Patients without any kidney diagnosis were less likely to receive optimal care than those coded for CKD [e.g. odds ratio for meeting blood pressure target 0.78 (95% confidence interval 0.76-0.79)]. Conclusion: Older age, male sex, diabetes and hypertension are associated with coding for those with biochemical CKD. CKD coding is associated with receiving key primary care interventions recommended for CKD. Increased efforts to incentivize CKD coding may improve outcomes for CKD patients.


Subject(s)
Clinical Audit/methods , Disease Management , Physicians, Primary Care , Primary Health Care/methods , Referral and Consultation , Renal Insufficiency, Chronic/therapy , Aged , Aged, 80 and over , England/epidemiology , Female , Glomerular Filtration Rate/physiology , Humans , Male , Middle Aged , Prevalence , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/physiopathology , Risk Factors , Wales/epidemiology
8.
Nephrol Dial Transplant ; 32(suppl_2): ii151-ii158, 2017 04 01.
Article in English | MEDLINE | ID: mdl-28339767

ABSTRACT

Background: Early diagnosis of chronic kidney disease (CKD) facilitates best management in primary care. Testing coverage of those at risk and translation into subsequent diagnostic coding will impact on observed CKD prevalence. Using initial data from 915 general practitioner (GP) practices taking part in a UK national audit, we seek to apply appropriate methods to identify outlying practices in terms of CKD stages 3-5 prevalence and diagnostic coding. Methods: We estimate expected numbers of CKD stages 3-5 cases in each practice, adjusted for key practice characteristics, and further inflate the control limits to account for overdispersion related to unobserved factors (including unobserved risk factors for CKD, and between-practice differences in coding and testing). Results: GP practice prevalence of coded CKD stages 3-5 ranges from 0.04 to 7.8%. Practices differ considerably in coding of CKD in individuals where CKD is indicated following testing (ranging from 0 to 97% of those with and glomerular filtration rate <60 mL/min/1.73 m 2 ). After adjusting for risk factors and overdispersion, the number of 'extreme' practices is reduced from 29 to 2.6% for the low-coded CKD prevalence outcome, from 21 to 1% for high-uncoded CKD stage and from 22 to 2.4% for low total (coded and uncoded) CKD prevalence. Thirty-one practices are identified as outliers for at least one of these outcomes. These can then be categorized into practices needing to address testing, coding or data storage/transfer issues. Conclusions: GP practice prevalence of coded CKD shows wide variation. Accounting for overdispersion is crucial in providing useful information about outlying practices for CKD prevalence.


Subject(s)
Renal Insufficiency, Chronic/diagnosis , Adult , Early Diagnosis , Female , Glomerular Filtration Rate , Humans , Male , Normal Distribution , Prevalence , Primary Health Care , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/physiopathology , Risk Factors
9.
BMJ Med ; 3(1): e000633, 2024.
Article in English | MEDLINE | ID: mdl-39175920

ABSTRACT

Objective: To quantify the potential advantages of using 10 year risk prediction models for cardiovascular disease, in combination with risk thresholds specific to both age and sex, to identify individuals at high risk of cardiovascular disease for allocation of statin treatment. Design: Prospective open cohort study. Setting: Primary care data from the UK Clinical Practice Research Datalink GOLD, linked with hospital admissions from Hospital Episode Statistics and national mortality records from the Office for National Statistics in England, 1 January 2006 to 31 May 2019. Participants: 1 046 736 individuals (aged 40-85 years) with no cardiovascular disease, diabetes, or a history of statin treatment at baseline using data from electronic health records. Main outcome measures: 10 year risk of cardiovascular disease, calculated with version 2 of the QRISK cardiovascular disease risk algorithm (QRISK2), with two main strategies to identify individuals at high risk: in strategy A, estimated risk was a fixed cut-off value of ≥10% (ie, as per the UK National Institute for Health and Care Excellence guidelines); in strategy B, estimated risk was ≥10% or ≥90th centile of age and sex specific risk distributions. Results: Compared with strategy A, strategy B stratified 20 241 (149.8%) more women aged ≤53 years and 9832 (150.2%) more men aged ≤47 years as having a high risk of cardiovascular disease; for all other ages the strategies were the same. Assuming that treatment with statins would be initiated in those identified as high risk, differences in the estimated gain in cardiovascular disease-free life years from statin treatment for strategy B versus strategy A were 0.14 and 0.16 years for women and men aged 40 years, respectively; among individuals aged 40-49 years, the numbers needed to treat to prevent one cardiovascular disease event for strategy B versus strategy A were 39 versus 21 in women and 19 versus 15 in men, respectively. Conclusions: This study quantified the potential gains in cardiovascular disease-free life years when implementing prevention strategies based on age and sex specific risk thresholds instead of a fixed risk threshold for allocation of statin treatment. Such gains should be weighed against the costs of treating more younger people with statins for longer.

10.
medRxiv ; 2024 Sep 23.
Article in English | MEDLINE | ID: mdl-39228710

ABSTRACT

Combining information from multiple GWASs for a disease and its risk factors has proven a powerful approach for development of polygenic risk scores (PRSs). This may be particularly useful for type 2 diabetes (T2D), a highly polygenic and heterogeneous disease where the additional predictive value of a PRS is unclear. Here, we use a meta-scoring approach to develop a metaPRS for T2D that incorporated genome-wide associations from both European and non-European genetic ancestries and T2D risk factors. We evaluated the performance of this metaPRS and benchmarked it against existing genome-wide PRS in 620,059 participants and 50,572 T2D cases amongst six diverse genetic ancestries from UK Biobank, INTERVAL, the All of Us Research Program, and the Singapore Multi-Ethnic Cohort. We show that our metaPRS was the most powerful PRS for predicting T2D in European population-based cohorts and had comparable performance to the top ancestry-specific PRS, highlighting its transferability. In UK Biobank, we show the metaPRS had stronger predictive power for 10-year risk than all individual risk factors apart from BMI and biomarkers of dysglycemia. The metaPRS modestly improved T2D risk stratification of QDiabetes risk scores for 10-year risk prediction, particularly when prioritising individuals for blood tests of dysglycemia. Overall, we present a highly predictive and transferrable PRS for T2D and demonstrate that the potential for PRS to incrementally improve T2D risk prediction when incorporated into UK guideline-recommended screening and risk prediction with a clinical risk score.

11.
Brain ; 135(Pt 1): 190-200, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22036957

ABSTRACT

Parsing of sound sources in the auditory environment or 'auditory scene analysis' is a computationally demanding cognitive operation that is likely to be vulnerable to the neurodegenerative process in Alzheimer's disease. However, little information is available concerning auditory scene analysis in Alzheimer's disease. Here we undertook a detailed neuropsychological and neuroanatomical characterization of auditory scene analysis in a cohort of 21 patients with clinically typical Alzheimer's disease versus age-matched healthy control subjects. We designed a novel auditory dual stream paradigm based on synthetic sound sequences to assess two key generic operations in auditory scene analysis (object segregation and grouping) in relation to simpler auditory perceptual, task and general neuropsychological factors. In order to assess neuroanatomical associations of performance on auditory scene analysis tasks, structural brain magnetic resonance imaging data from the patient cohort were analysed using voxel-based morphometry. Compared with healthy controls, patients with Alzheimer's disease had impairments of auditory scene analysis, and segregation and grouping operations were comparably affected. Auditory scene analysis impairments in Alzheimer's disease were not wholly attributable to simple auditory perceptual or task factors; however, the between-group difference relative to healthy controls was attenuated after accounting for non-verbal (visuospatial) working memory capacity. These findings demonstrate that clinically typical Alzheimer's disease is associated with a generic deficit of auditory scene analysis. Neuroanatomical associations of auditory scene analysis performance were identified in posterior cortical areas including the posterior superior temporal lobes and posterior cingulate. This work suggests a basis for understanding a class of clinical symptoms in Alzheimer's disease and for delineating cognitive mechanisms that mediate auditory scene analysis both in health and in neurodegenerative disease.


Subject(s)
Alzheimer Disease/physiopathology , Auditory Perception/physiology , Brain/physiopathology , Acoustic Stimulation , Aged , Alzheimer Disease/psychology , Cues , Female , Humans , Male , Memory, Short-Term/physiology , Middle Aged , Neuropsychological Tests
12.
Age Ageing ; 42(6): 696-701, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24080787

ABSTRACT

BACKGROUND: many chronic conditions have their roots in modifiable health-related behaviours. METHODS: a total of 4,286 women aged 60-79 in the British Women's Heart and Health Study are followed up for incident cardiovascular disease (CVD), arthritis and locomotor disability over 7 years. Self-reported smoking, alcohol consumption, exercise and fruit intake at baseline is also available. Associations between these and each outcome, plus a composite outcome, are investigated in those without prevalent disease at baseline using logistic regression with multiple imputation. RESULTS: ex-smokers and current smokers showed increased odds of locomotor disability, CVD and the combined outcome. Less regular exercisers had increased odds of all outcomes, particularly locomotor disability. There was no evidence that alcohol or fruit intake was associated with any outcome. Population attributable fractions (PAFs) suggest in addition to the influence of smoking and alcohol, exercise accounts for 9% of incident locomotor disability, 5% of CVD and 4% of arthritis. All four lifestyle factors combined account for 17% of incident locomotor disability and 9% of incident conditions combined. CONCLUSIONS: never smokers and regular exercisers had substantially reduced odds of 7-year disability onset. Low PAFs suggest changes in health-related behaviours in older women would result in only modest reductions in common chronic conditions.


Subject(s)
Aging , Arthritis/epidemiology , Cardiovascular Diseases/epidemiology , Choice Behavior , Health Behavior , Life Style , Motor Activity , Age Factors , Aged , Alcohol Drinking , Arthritis/prevention & control , Cardiovascular Diseases/prevention & control , Dependent Ambulation , Diet , Disability Evaluation , Exercise , Female , Fruit , Health Knowledge, Attitudes, Practice , Humans , Incidence , Linear Models , Logistic Models , Middle Aged , Mobility Limitation , Odds Ratio , Prospective Studies , Risk Factors , Risk Reduction Behavior , Sex Factors , Smoking/adverse effects , Smoking/epidemiology , Smoking Cessation , Smoking Prevention , Time Factors , United Kingdom/epidemiology
13.
Protein J ; 42(6): 802-810, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37787923

ABSTRACT

NifA is a σ54 activator that turns on bacterial nitrogen fixation under reducing conditions and when fixed cellular nitrogen levels are low. The redox sensing mechanism in NifA is poorly understood. In α- and ß-proteobacteria, redox sensing involves two pairs of Cys residues within and immediately following the protein's central AAA+ domain. In this work, we examine if an additional Cys pair that is part of a C(X)5 C motif and located immediately upstream of the DNA binding domain of NifA from the α-proteobacterium Gluconacetobacter diazotrophicus (Gd) is involved in redox sensing. We hypothesize that the Cys residues' redox state may directly influence the DNA binding domain's DNA binding affinity and/or alter the protein's oligomeric sate. Two DNA binding domain constructs were generated, a longer construct (2C-DBD), consisting of the DNA binding domain with the upstream Cys pair, and a shorter construct (NC-DBD) that lacks the Cys pair. The Kd of NC-DBD for its cognate DNA sequence (nifH-UAS) is equal to 20.0 µM. The Kd of 2C-DBD for nifH-UAS when the Cys pair is oxidized is 34.5 µM. Reduction of the disulfide bond does not change the DNA binding affinity. Additional experiments indicate that the redox state of the Cys residues does not influence the secondary structure or oligomerization state of the NifA DNA binding domain. Together, these results demonstrate that the Cys pair upstream of the DNA binding domain of Gd-NifA does not regulate DNA binding or domain dimerization in a redox dependent manner.


Subject(s)
Bacterial Proteins , Nitrogenase , Nitrogenase/genetics , Nitrogenase/metabolism , Bacterial Proteins/chemistry , Transcription Factors/genetics , Nitrogen Fixation/genetics , DNA/metabolism , Genes, Bacterial
14.
Pharmaceuticals (Basel) ; 16(3)2023 Mar 22.
Article in English | MEDLINE | ID: mdl-36986567

ABSTRACT

The entry of proteins through the cell membrane is challenging, thus limiting their use as potential therapeutics. Seven cell-penetrating peptides, designed in our laboratory, were evaluated for the delivery of proteins. Fmoc solid-phase peptide synthesis was utilized for the synthesis of seven cyclic or hybrid cyclic-linear amphiphilic peptides composed of hydrophobic (tryptophan (W) or 3,3-diphenylalanine (Dip) and positively-charged arginine (R) residues, such as [WR]4, [WR]9, [WWRR]4, [WWRR]5, [(RW)5K](RW)5, [R5K]W7, and [DipR]5. Confocal microscopy was used to screen the peptides as a protein delivery system of model cargo proteins, green and red fluorescein proteins (GFP and RFP). Based on the confocal microscopy results, [WR]9 and [DipR]5 were found to be more efficient among all the peptides and were selected for further studies. [WR]9 (1-10 µM) + protein (GFP and RFP) physical mixture did not show high cytotoxicity (>90% viability) in triple-negative breast cancer cells (MDA-MB-231) after 24 h, while [DipR]5 (1-10 µM) physical mixture with GFP exhibited more than 81% cell viability. Confocal microscopy images revealed internalization of GFP and RFP in MDA-MB-231 cells using [WR]9 (2-10 µM) and [DipR]5 (1-10 µM). Fluorescence-activated cell sorting (FACS) analysis indicated that the cellular uptake of GFP was concentration-dependent in the presence of [WR]9 in MDA-MB-231 cells after 3 h of incubation at 37 °C. The concentration-dependent uptake of GFP and RFP was also observed in the presence of [DipR5] in SK-OV-3 and MDA-MB-231 cells after 3 h of incubation at 37 °C. FACS analysis indicated that the cellular uptake of GFP in the presence of [WR]9 was partially decreased by methyl-ß-cyclodextrin and nystatin as endocytosis inhibitors after 3 h of incubation in MDA-MB-231 cells, whereas nystatin and chlorpromazine as endocytosis inhibitors slightly reduced the uptake of GFP in the presence of [DipR]5 after 3 h of incubation in MDA-MB-231. [WR]9 was able to deliver therapeutically relevant proteins (Histone H2A) at different concentrations. These results provide insight into the use of amphiphilic cyclic peptides in the delivery of protein-related therapeutics.

15.
PLoS One ; 18(9): e0292240, 2023.
Article in English | MEDLINE | ID: mdl-37773956

ABSTRACT

OBJECTIVE: To provide quantitative evidence for systematically prioritising individuals for full formal cardiovascular disease (CVD) risk assessment using primary care records with a novel tool (eHEART) with age- and sex- specific risk thresholds. METHODS AND ANALYSIS: eHEART was derived using landmark Cox models for incident CVD with repeated measures of conventional CVD risk predictors in 1,642,498 individuals from the Clinical Practice Research Datalink. Using 119,137 individuals from UK Biobank, we modelled the implications of initiating guideline-recommended statin therapy using eHEART with age- and sex-specific prioritisation thresholds corresponding to 5% false negative rates to prioritise adults aged 40-69 years in a population in England for invitation to a formal CVD risk assessment. RESULTS: Formal CVD risk assessment on all adults would identify 76% and 49% of future CVD events amongst men and women respectively, and 93 (95% CI: 90, 95) men and 279 (95% CI: 259, 297) women would need to be screened (NNS) to prevent one CVD event. In contrast, if eHEART was first used to prioritise individuals for formal CVD risk assessment, we would identify 73% and 47% of future events amongst men and women respectively, and a NNS of 75 (95% CI: 72, 77) men and 162 (95% CI: 150, 172) women. Replacing the age- and sex-specific prioritisation thresholds with a 10% threshold identify around 10% less events. CONCLUSIONS: The use of prioritisation tools with age- and sex-specific thresholds could lead to more efficient CVD assessment programmes with only small reductions in effectiveness at preventing new CVD events.


Subject(s)
Cardiovascular Diseases , Adult , Male , Humans , Female , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , England/epidemiology , Risk Assessment , Primary Health Care , Risk Factors
16.
J Am Heart Assoc ; 12(15): e029296, 2023 08.
Article in English | MEDLINE | ID: mdl-37489768

ABSTRACT

Background The aim of this study was to provide quantitative evidence of the use of polygenic risk scores for systematically identifying individuals for invitation for full formal cardiovascular disease (CVD) risk assessment. Methods and Results A total of 108 685 participants aged 40 to 69 years, with measured biomarkers, linked primary care records, and genetic data in UK Biobank were used for model derivation and population health modeling. Prioritization tools using age, polygenic risk scores for coronary artery disease and stroke, and conventional risk factors for CVD available within longitudinal primary care records were derived using sex-specific Cox models. We modeled the implications of initiating guideline-recommended statin therapy after prioritizing individuals for invitation to a formal CVD risk assessment. If primary care records were used to prioritize individuals for formal risk assessment using age- and sex-specific thresholds corresponding to 5% false-negative rates, then the numbers of men and women needed to be screened to prevent 1 CVD event are 149 and 280, respectively. In contrast, adding polygenic risk scores to both prioritization and formal assessments, and selecting thresholds to capture the same number of events, resulted in a number needed to screen of 116 for men and 180 for women. Conclusions Using both polygenic risk scores and primary care records to prioritize individuals at highest risk of a CVD event for a formal CVD risk assessment can efficiently prioritize those who need interventions the most than using primary care records alone. This could lead to better allocation of resources by reducing the number of risk assessments in primary care while still preventing the same number of CVD events.


Subject(s)
Cardiovascular Diseases , Coronary Artery Disease , Stroke , Male , Humans , Female , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/genetics , Risk Factors , Coronary Artery Disease/complications , Risk Assessment/methods , Stroke/epidemiology , Stroke/genetics , Stroke/prevention & control
17.
Eur J Health Econ ; 24(7): 1033-1045, 2023 Sep.
Article in English | MEDLINE | ID: mdl-36239877

ABSTRACT

The objective of this article was to assess the cost-effectiveness of screening strategies for cardiovascular diseases (CVD). A decision analytic model was constructed to estimate the costs and benefits of one-off screening strategies differentiated by screening age, sex and the threshold for initiating statin therapy ("uniform" or "age-adjusted") from the Spanish NHS perspective. The age-adjusted thresholds were configured so that the same number of people at high risk would be treated as under the uniform threshold. Health benefit was measured in quality-adjusted life years (QALY). Transition rates were estimated from the European Prospective Investigation into Cancer and Nutrition (EPIC-CVD), a large multicentre nested case-cohort study with 12 years of follow-up. Unit costs of primary care, hospitalizations and CVD care were taken from the Spanish health system. Univariate and probabilistic sensitivity analyses were employed. The comparator was no systematic screening program. The base case model showed that the most efficient one-off strategy is to screen both men and women at 40 years old using a uniform risk threshold for initiating statin treatment (Incremental Cost-Effectiveness Ratio of €3,274/QALY and €6,085/QALY for men and women, respectively). Re-allocating statin treatment towards younger individuals at high risk for their age and sex would not offset the benefit obtained using those same resources to treat older individuals. Results are sensitive to assumptions about CVD incidence rates. To conclude, one-off screening for CVD using a uniform risk threshold appears cost-effective compared with no systematic screening. These results should be evaluated in clinical studies.


Subject(s)
Cardiovascular Diseases , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Male , Humans , Female , Adult , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/prevention & control , Cost-Benefit Analysis , Cohort Studies , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Prospective Studies , Quality-Adjusted Life Years
18.
Seizure ; 94: 26-32, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34852983

ABSTRACT

PURPOSE: Following a single seizure, or recent epilepsy diagnosis, it is difficult to balance risk of medication side effects with the potential to prevent seizure recurrence. A prediction model was developed and validated enabling risk stratification which in turn informs treatment decisions and individualises counselling. METHODS: Data from a randomised controlled trial was used to develop a prediction model for risk of seizure recurrence following a first seizure or diagnosis of epilepsy. Time-to-event data was modelled via Cox's proportional hazards regression. Model validity was assessed via discrimination and calibration using the original dataset and also using three external datasets - National General Practice Survey of Epilepsy (NGPSE), Western Australian first seizure database (WA) and FIRST (Italian dataset of people with first tonic-clonic seizures). RESULTS: People with neurological deficit, focal seizures, abnormal EEG, not indicated for CT/MRI scan, or not immediately treated have a significantly higher risk of seizure recurrence. Discrimination was fair and consistent across the datasets (c-statistics: 0.555 (NGPSE); 0.558 (WA); 0.597 (FIRST)). Calibration plots showed good agreement between observed and predicted probabilities in NGPSE at one and three years. Plots for WA and FIRST showed poorer agreement with the model underpredicting risk in WA, and over-predicting in FIRST. This was resolved following model recalibration. CONCLUSION: The model performs well in independent data especially when recalibrated. It should now be used in clinical practice as it can improve the lives of people with single seizures and early epilepsy by enabling targeted treatment choices and more informed patient counselling.


Subject(s)
Anticonvulsants , Epilepsy , Anticonvulsants/therapeutic use , Australia , Epilepsy/drug therapy , Epilepsy/epidemiology , Humans , Probability , Seizures/drug therapy , Seizures/epidemiology
19.
BMJ Open ; 12(10): e064513, 2022 10 11.
Article in English | MEDLINE | ID: mdl-36220323

ABSTRACT

OBJECTIVE: To examine the association between practice percentage coding of chronic kidney disease (CKD) in primary care with risk of subsequent hospitalisations and death. DESIGN: Retrospective cohort study using linked electronic healthcare records. SETTING: 637 general practitioner (GP) practices in England. PARTICIPANTS: 167 208 patients with CKD stages 3-5 identified by 2 measures of estimated glomerular filtration rate <60 mL/min/1.73 m2, separated by at least 90 days, excluding those with coded initiation of renal replacement therapy. MAIN OUTCOME MEASURES: Hospitalisations with cardiovascular (CV) events, heart failure (HF), acute kidney injury (AKI) and all-cause mortality RESULTS: Participants were followed for (median) 3.8 years for hospital outcomes and 4.3 years for deaths. Rates of hospitalisations with CV events and HF were lower in practices with higher percentage CKD coding. Trends of a small reduction in AKI but no substantial change in rate of deaths were also observed as CKD coding increased. Compared with patients in the median performing practice (74% coded), patients in practices coding 55% of CKD cases had a higher rate of CV hospitalisations (HR 1.061 (95% CI 1.015 to 1.109)) and HF hospitalisations (HR 1.097 (95% CI 1.013 to 1.187)) and patients in practices coding 88% of CKD cases had a reduced rate of CV hospitalisations (HR 0.957 (95% CI 0.920 to 0.996)) and HF hospitalisations (HR 0.918 (95% CI 0.855 to 0.985)). We estimate that 9.0% of CV hospitalisations and 16.0% of HF hospitalisations could be prevented by improving practice CKD coding from 55% to 88%. Prescription of antihypertensives was the most dominant predictor of a reduction in hospitalisation rates for patients with CKD, followed by albuminuria testing and use of statins. CONCLUSIONS: Higher levels of CKD coding by GP practices were associated with lower rates of CV and HF events, which may be driven by increased use of antihypertensives and regular albuminuria testing, although residual confounding cannot be ruled out.


Subject(s)
Acute Kidney Injury , Heart Failure , Hydroxymethylglutaryl-CoA Reductase Inhibitors , Renal Insufficiency, Chronic , Acute Kidney Injury/complications , Albuminuria/complications , Antihypertensive Agents , Cohort Studies , Glomerular Filtration Rate , Heart Failure/complications , Hospitalization , Humans , Primary Health Care , Renal Insufficiency, Chronic/complications , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/therapy , Retrospective Studies
20.
Health Econ ; 20(7): 842-52, 2011 Jul.
Article in English | MEDLINE | ID: mdl-20799342

ABSTRACT

Cost-effectiveness analysis is usually based on life-years gained estimated from all-cause mortality. When an intervention affects only a few causes of death accounting for a small fraction of all deaths, this approach may lack precision. We develop a novel technique for cost-effectiveness analysis when life-years gained are estimated from cause-specific mortality, allowing for competing causes of death. In the context of randomised trial data, we adjust for other-cause mortality combined across randomised groups. This method yields a greater precision than analysis based on total mortality, and we show application to life-years gained, quality-adjusted life-years gained, incremental costs, and cost effectiveness. In multi-state health economic models, however, mortality from competing causes is commonly derived from national statistics and is assumed to be known and equal across intervention groups. In such models, our method based on cause-specific mortality and standard methods using total mortality give essentially identical estimates and precision. The methods are applied to a randomised trial and a health economic model, both of screening for abdominal aortic aneurysm. A gain in precision for cost-effectiveness estimates is clearly helpful for decision making, but it is important to ensure that 'cause-specific mortality' is defined to include all causes of death potentially affected by the intervention.


Subject(s)
Aortic Aneurysm, Abdominal/diagnosis , Mass Screening/economics , Quality-Adjusted Life Years , Aortic Aneurysm, Abdominal/economics , Aortic Aneurysm, Abdominal/mortality , Aortic Aneurysm, Abdominal/surgery , Cause of Death , Cost-Benefit Analysis , Humans , Kaplan-Meier Estimate , Markov Chains , Models, Economic , Randomized Controlled Trials as Topic
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