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1.
Article in English | MEDLINE | ID: mdl-38997229

ABSTRACT

BACKGROUND: We investigated the impact of Drug-Drug Interactions (DDIs) on virologic control among HIV-positive pregnant women initiating antiretroviral therapy while identifying drivers for Traditional Medicine (TM) use and exploring the nature and extent of TM-related DDIs. METHODS: Employing a three-pronged approach, we examined DDIs arising from comedication, including TM, in ART. The DolPHIN-2 trial (NCT03249181) randomized 268 HIV-positive pregnant women in Uganda and South Africa to dolutegravir (DTG)-based (135) or efavirenz-based (133) regimens while systematically recording comedications and screening for DDIs. We used Cox regression models to compare time-to-virologic control between participants with and without DDIs. We conducted in-depth interviews and focus group discussions among 37 and 67 women with and without HIV, respectively, to explore reasons for TM use during pregnancy. Additionally, in-vitro and in-vivo studies evaluated the composition and impact of clay-based TM, mumbwa, on DTG plasma exposure. RESULTS: The baseline prevalence of DDIs was 67.2%, with TM use prevalent in 34% of participants, with mumbwa being the most frequent (76%, 69/91). There was no difference in virologic response between participants with and without DDIs. Fetal health and cultural norms were among the reasons cited for TM use. Analysis of mumbwa rods confirmed significant amounts of aluminium (8.4%-13.9%) and iron (4%-6%). In Balb-C mice, coadministration of mumbwa led to a reduction in DTG exposure observed in the AUC0-24 (-21%; P = 0.0271) and C24 (-53%; P = 0.0028). CONCLUSIONS: The widespread use of clay-based TM may compromise HIV treatment, necessitating medication screening and counselling to manage DDIs in pregnant women.

2.
Nat Rev Cardiol ; 2024 Jul 19.
Article in English | MEDLINE | ID: mdl-39030270

ABSTRACT

For more than 60 years, humans have travelled into space. Until now, the majority of astronauts have been professional, government agency astronauts selected, in part, for their superlative physical fitness and the absence of disease. Commercial spaceflight is now becoming accessible to members of the public, many of whom would previously have been excluded owing to unsatisfactory fitness or the presence of cardiorespiratory diseases. While data exist on the effects of gravitational and acceleration (G) forces on human physiology, data on the effects of the aerospace environment in unselected members of the public, and particularly in those with clinically significant pathology, are limited. Although short in duration, these high acceleration forces can potentially either impair the experience or, more seriously, pose a risk to health in some individuals. Rather than expose individuals with existing pathology to G forces to collect data, computational modelling might be useful to predict the nature and severity of cardiovascular diseases that are of sufficient risk to restrict access, require modification, or suggest further investigation or training before flight. In this Review, we explore state-of-the-art, zero-dimensional, compartmentalized models of human cardiovascular pathophysiology that can be used to simulate the effects of acceleration forces, homeostatic regulation and ventilation-perfusion matching, using data generated by long-arm centrifuge facilities of the US National Aeronautics and Space Administration and the European Space Agency to risk stratify individuals and help to improve safety in commercial suborbital spaceflight.

3.
Expert Rev Cardiovasc Ther ; 22(7): 339-345, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38949642

ABSTRACT

BACKGROUND: Triple antithrombotic therapy (TAT) with aspirin, a P2Y12 inhibitor, and oral anticoagulation in patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI) raises concerns about increased bleeding. Regimens incorporating more potent P2Y12 inhibitors over clopidogrel have not been investigated adequately. RESEARCH DESIGN AND METHODS: A retrospective observational study was performed on 387 patients with AF receiving TAT for 1 month (n = 236) or ≤1 week (n = 151) after PCI. Major and clinically relevant non-major bleeding and major adverse cardiac and cerebrovascular events (MACCE) were assessed up to 30 days post-procedure. RESULTS: Bleeding was less frequent with ≤1 week versus 1 month of TAT (3.3 vs 9.3%; p = 0.025) while MACCE were similar (4.6 vs 4.7%; p = 0.998). No differences in bleeding or MACCE were observed between ticagrelor/prasugrel and clopidogrel regimens. For patients receiving ≤1 week of TAT, no excess of MACCE was seen in the subgroup given no further aspirin post-PCI compared with those given aspirin for up to 1 week (3.6 vs 5.2%). CONCLUSIONS: TAT post-PCI for ≤1 week was associated with less bleeding despite greater use of ticagrelor/prasugrel but similar MACCE versus 1-month TAT. These findings support further studies on safety and efficacy of dual therapy with ticagrelor/prasugrel immediately after PCI.


Subject(s)
Anticoagulants , Aspirin , Atrial Fibrillation , Clopidogrel , Drug Therapy, Combination , Hemorrhage , Percutaneous Coronary Intervention , Platelet Aggregation Inhibitors , Purinergic P2Y Receptor Antagonists , Humans , Atrial Fibrillation/drug therapy , Atrial Fibrillation/complications , Percutaneous Coronary Intervention/methods , Male , Female , Retrospective Studies , Aged , Middle Aged , Hemorrhage/chemically induced , Aspirin/administration & dosage , Aspirin/therapeutic use , Aspirin/adverse effects , Clopidogrel/administration & dosage , Clopidogrel/therapeutic use , Clopidogrel/adverse effects , Platelet Aggregation Inhibitors/administration & dosage , Platelet Aggregation Inhibitors/adverse effects , Platelet Aggregation Inhibitors/therapeutic use , Anticoagulants/administration & dosage , Anticoagulants/adverse effects , Anticoagulants/therapeutic use , Purinergic P2Y Receptor Antagonists/administration & dosage , Purinergic P2Y Receptor Antagonists/therapeutic use , Purinergic P2Y Receptor Antagonists/adverse effects , Time Factors , Treatment Outcome , Fibrinolytic Agents/administration & dosage , Fibrinolytic Agents/therapeutic use , Fibrinolytic Agents/adverse effects , Aged, 80 and over , Ticagrelor/administration & dosage , Ticagrelor/therapeutic use , Ticagrelor/adverse effects
4.
Protein Sci ; 33(7): e5069, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38864740

ABSTRACT

Photoconvertible fluorescent proteins (pcFPs) undergo a slow photochemical transformation when irradiated with blue light. Since their emission is shifted from green to red, pcFPs serve as convenient fusion tags in several cutting-edge biological imaging technologies. Here, a pcFP termed the Least Evolved Ancestor (LEA) was used as a model system to determine the rate-limiting step of photoconversion. Perdeuterated histidine residues were introduced by isotopic enrichment and chromophore content was monitored by absorbance. pH-dependent photoconversion experiments were carried out by exposure to 405-nm light followed by dark equilibration. The loss of green chromophore correlated well with the rise of red, and maximum photoconversion rates were observed at pH 6.5 (0.059 ± 0.001 min-1 for red color acquisition). The loss of green and the rise of red provided deuterium kinetic isotope effects (DKIEs) that were identical within error, 2.9 ± 0.9 and 3.8 ± 0.6, respectively. These data indicate that there is one rate-determining step in the light reactions of photoconversion, and that CH bond cleavage occurs in the transition state of this step. We propose that these reactions are rate-limited on the min time scale by the abstraction of a proton at the His62 beta-carbon. A conformational intermediate such as a twisted or isomerized chromophore is proposed to slowly equilibrate in the dark to generate the red form. Additionally, His62 may shuttle protons to activate Glu211 to serve as a general base, while also facilitating beta-elimination. This idea is supported by a recent X-ray structure of methylated His62.


Subject(s)
Luminescent Proteins , Kinetics , Luminescent Proteins/chemistry , Green Fluorescent Proteins/chemistry , Green Fluorescent Proteins/genetics , Hydrogen-Ion Concentration , Photochemical Processes , Red Fluorescent Protein , Histidine/chemistry , Deuterium/chemistry , Light
5.
Am J Physiol Heart Circ Physiol ; 327(1): H182-H190, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38787386

ABSTRACT

Murray's law has been viewed as a fundamental law of physiology. Relating blood flow ([Formula: see text]) to vessel diameter (D) ([Formula: see text]·âˆ·D3), it dictates minimum lumen area (MLA) targets for coronary bifurcation percutaneous coronary intervention (PCI). The cubic exponent (3.0), however, has long been disputed, with alternative theoretical derivations, arguing this should be closer to 2.33 (7/3). The aim of this meta-analysis was to quantify the optimum flow-diameter exponent in human and mammalian coronary arteries. We conducted a systematic review and meta-analysis of all articles quantifying an optimum flow-diameter exponent for mammalian coronary arteries within the Cochrane library, PubMed Medline, Scopus, and Embase databases on 20 March 2023. A random-effects meta-analysis was used to determine a pooled flow-diameter exponent. Risk of bias was assessed with the National Institutes of Health (NIH) quality assessment tool, funnel plots, and Egger regression. From a total of 4,772 articles, 18 were suitable for meta-analysis. Studies included data from 1,070 unique coronary trees, taken from 372 humans and 112 animals. The pooled flow diameter exponent across both epicardial and transmural arteries was 2.39 (95% confidence interval: 2.24-2.54; I2 = 99%). The pooled exponent of 2.39 showed very close agreement with the theoretical exponent of 2.33 (7/3) reported by Kassab and colleagues. This exponent may provide a more accurate description of coronary morphometric scaling in human and mammalian coronary arteries, as compared with Murray's original law. This has important implications for the assessment, diagnosis, and interventional treatment of coronary artery disease.


Subject(s)
Coronary Circulation , Coronary Vessels , Animals , Humans , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Coronary Vessels/diagnostic imaging , Models, Cardiovascular , Percutaneous Coronary Intervention
6.
Curr Biol ; 34(11): 2487-2501.e3, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38772361

ABSTRACT

Sleep is broadly conserved across the animal kingdom but can vary widely between species. It is currently unclear which selective pressures and regulatory mechanisms influence differences in sleep between species. The fruit fly Drosophila melanogaster has become a successful model system for examining sleep regulation and function, but little is known about the sleep patterns in many related fly species. Here, we find that fly species with adaptations to extreme desert environments, including D. mojavensis, exhibit strong increases in baseline sleep compared with D. melanogaster. Long-sleeping D. mojavensis show intact homeostasis, indicating that desert flies carry an elevated drive for sleep. In addition, D. mojavensis exhibit altered abundance or distribution of several sleep/wake-related neuromodulators and neuropeptides that are consistent with their reduced locomotor activity and increased sleep. Finally, we find that in a nutrient-deprived environment, the sleep patterns of individual D. mojavensis are strongly correlated with their survival time and that disrupting sleep via constant light stimulation renders D. mojavensis more sensitive to starvation. Our results demonstrate that D. mojavensis is a novel model for studying organisms with high sleep drive and for exploring sleep strategies that provide resilience in extreme environments.


Subject(s)
Drosophila , Sleep , Animals , Sleep/physiology , Drosophila/physiology , Drosophila melanogaster/physiology , Stress, Physiological , Female , Male , Desert Climate , Species Specificity
7.
FASEB J ; 38(10): e23647, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38787599

ABSTRACT

Arginine methylation is a protein posttranslational modification important for the development of skeletal muscle mass and function. Despite this, our understanding of the regulation of arginine methylation under settings of health and disease remains largely undefined. Here, we investigated the regulation of arginine methylation in skeletal muscles in response to exercise and hypertrophic growth, and in diseases involving metabolic dysfunction and atrophy. We report a limited regulation of arginine methylation under physiological settings that promote muscle health, such as during growth and acute exercise, nor in disease models of insulin resistance. In contrast, we saw a significant remodeling of asymmetric dimethylation in models of atrophy characterized by the loss of innervation, including in muscle biopsies from patients with myotrophic lateral sclerosis (ALS). Mass spectrometry-based quantification of the proteome and asymmetric arginine dimethylome of skeletal muscle from individuals with ALS revealed the largest compendium of protein changes with the identification of 793 regulated proteins, and novel site-specific changes in asymmetric dimethyl arginine (aDMA) of key sarcomeric and cytoskeletal proteins. Finally, we show that in vivo overexpression of PRMT1 and aDMA resulted in increased fatigue resistance and functional recovery in mice. Our study provides evidence for asymmetric dimethylation as a regulator of muscle pathophysiology and presents a valuable proteomics resource and rationale for numerous methylated and nonmethylated proteins, including PRMT1, to be pursued for therapeutic development in ALS.


Subject(s)
Amyotrophic Lateral Sclerosis , Arginine , Muscle, Skeletal , Protein-Arginine N-Methyltransferases , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Arginine/metabolism , Arginine/analogs & derivatives , Humans , Amyotrophic Lateral Sclerosis/metabolism , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/pathology , Animals , Mice , Protein-Arginine N-Methyltransferases/metabolism , Protein-Arginine N-Methyltransferases/genetics , Male , Methylation , Female , Protein Processing, Post-Translational , Mice, Inbred C57BL , Proteome/metabolism
8.
Nat Commun ; 15(1): 4210, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38806504

ABSTRACT

The chemokine CXCL12 promotes glioblastoma (GBM) recurrence after radiotherapy (RT) by facilitating vasculogenesis. Here we report outcomes of the dose-escalation part of GLORIA (NCT04121455), a phase I/II trial combining RT and the CXCL12-neutralizing aptamer olaptesed pegol (NOX-A12; 200/400/600 mg per week) in patients with incompletely resected, newly-diagnosed GBM lacking MGMT methylation. The primary endpoint was safety, secondary endpoints included maximum tolerable dose (MTD), recommended phase II dose (RP2D), NOX-A12 plasma levels, topography of recurrence, tumor vascularization, neurologic assessment in neuro-oncology (NANO), quality of life (QOL), median progression-free survival (PFS), 6-months PFS and overall survival (OS). Treatment was safe with no dose-limiting toxicities or treatment-related deaths. The MTD has not been reached and, thus, 600 mg per week of NOX-A12 was established as RP2D for the ongoing expansion part of the trial. With increasing NOX-A12 dose levels, a corresponding increase of NOX-A12 plasma levels was observed. Of ten patients enrolled, nine showed radiographic responses, four reached partial remission. All but one patient (90%) showed at best response reduced perfusion values in terms of relative cerebral blood volume (rCBV). The median PFS was 174 (range 58-260) days, 6-month PFS was 40.0% and the median OS 389 (144-562) days. In a post-hoc exploratory analysis of tumor tissue, higher frequency of CXCL12+ endothelial and glioma cells was significantly associated with longer PFS under NOX-A12. Our data imply safety of NOX-A12 and its efficacy signal warrants further investigation.


Subject(s)
Aptamers, Nucleotide , Brain Neoplasms , Chemokine CXCL12 , Glioblastoma , Humans , Glioblastoma/radiotherapy , Glioblastoma/drug therapy , Aptamers, Nucleotide/administration & dosage , Chemokine CXCL12/blood , Male , Female , Middle Aged , Aged , Brain Neoplasms/radiotherapy , Brain Neoplasms/drug therapy , Adult , Maximum Tolerated Dose , Quality of Life , Neoplasm Recurrence, Local
9.
bioRxiv ; 2024 May 05.
Article in English | MEDLINE | ID: mdl-38746109

ABSTRACT

KIR3DL1 is a polymorphic inhibitory Natural Killer (NK) cell receptor that recognizes Human Leukocyte Antigen (HLA) class I allotypes that contain the Bw4 motif. Structural analyses have shown that in addition to residues 77-83 that span the Bw4 motif, polymorphism at other sites throughout the HLA molecule can influence the interaction with KIR3DL1. Given the extensive polymorphism of both KIR3DL1 and HLA class I, we built a machine learning prediction model to describe the influence of allotypic variation on the binding of KIR3DL1 to HLA class I. Nine KIR3DL1 tetramers were screened for reactivity against a panel of HLA class I molecules which revealed different patterns of specificity for each KIR3DL1 allotype. Separate models were trained for each of KIR3DL1 allotypes based on the full amino sequence of exons 2 and 3 encoding the α1 and α2 domains of the class I HLA allotypes, the set of polymorphic positions that span the Bw4 motif, or the positions that encode α1 and α2 but exclude the connecting loops. The Multi-Label-Vector-Optimization (MLVO) model trained on all alpha helix positions performed best with AUC scores ranging from 0.74 to 0.974 for the 9 KIR3DL1 allotype models. We show that a binary division into binder and non-binder is not precise, and that intermediate levels exist. Using the same models, within the binder group, high- and low-binder categories can also be predicted, the regions in HLA affecting the high vs low binder being completely distinct from the classical Bw4 motif. We further show that these positions affect binding affinity in a nonadditive way and induce deviations from linear models used to predict interaction strength. We propose that this approach should be used in lieu of simpler binding models based on a single HLA motif.

10.
Nat Commun ; 15(1): 4513, 2024 May 27.
Article in English | MEDLINE | ID: mdl-38802361

ABSTRACT

Urothelial bladder cancer (UC) has a wide tumor biological spectrum with challenging prognostic stratification and relevant therapy-associated morbidity. Most molecular classifications relate only indirectly to the therapeutically relevant protein level. We improve the pre-analytics of clinical samples for proteome analyses and characterize a cohort of 434 samples with 242 tumors and 192 paired normal mucosae covering the full range of UC. We evaluate sample-wise tumor specificity and rank biomarkers by target relevance. We identify robust proteomic subtypes with prognostic information independent from histopathological groups. In silico drug prediction suggests efficacy of several compounds hitherto not in clinical use. Both in silico and in vitro data indicate predictive value of the proteomic clusters for these drugs. We underline that proteomics is relevant for personalized oncology and provide abundance and tumor specificity data for a large part of the UC proteome ( www.cancerproteins.org ).


Subject(s)
Biomarkers, Tumor , Proteomics , Urinary Bladder Neoplasms , Humans , Proteomics/methods , Urinary Bladder Neoplasms/metabolism , Urinary Bladder Neoplasms/pathology , Urinary Bladder Neoplasms/genetics , Biomarkers, Tumor/metabolism , Proteome/metabolism , Female , Male , Urothelium/pathology , Urothelium/metabolism , Aged , Prognosis , Middle Aged , Aged, 80 and over
11.
MAGMA ; 2024 Apr 13.
Article in English | MEDLINE | ID: mdl-38613715

ABSTRACT

PURPOSE: Use a conference challenge format to compare machine learning-based gamma-aminobutyric acid (GABA)-edited magnetic resonance spectroscopy (MRS) reconstruction models using one-quarter of the transients typically acquired during a complete scan. METHODS: There were three tracks: Track 1: simulated data, Track 2: identical acquisition parameters with in vivo data, and Track 3: different acquisition parameters with in vivo data. The mean squared error, signal-to-noise ratio, linewidth, and a proposed shape score metric were used to quantify model performance. Challenge organizers provided open access to a baseline model, simulated noise-free data, guides for adding synthetic noise, and in vivo data. RESULTS: Three submissions were compared. A covariance matrix convolutional neural network model was most successful for Track 1. A vision transformer model operating on a spectrogram data representation was most successful for Tracks 2 and 3. Deep learning (DL) reconstructions with 80 transients achieved equivalent or better SNR, linewidth and fit error compared to conventional 320 transient reconstructions. However, some DL models optimized linewidth and SNR without actually improving overall spectral quality, indicating a need for more robust metrics. CONCLUSION: DL-based reconstruction pipelines have the promise to reduce the number of transients required for GABA-edited MRS.

13.
Adv Radiat Oncol ; 9(5): 101466, 2024 May.
Article in English | MEDLINE | ID: mdl-38550377

ABSTRACT

Purpose: A correct placement of the applicator during intraoperative radiation therapy for brain metastasis is of paramount importance, to deliver a precise and safe treatment. The applicator-to-surface contact assessment cannot be performed under direct observation because the applicator itself limits the visual range. No image guided verification is currently performed intracranially. We hypothesize that image guided intraoperative radiation therapy would assure a more precise delivery in the target area. We describe our workflow in a first in-human experience. Methods and Materials: Phantom-based measurements were performed to reach the best cone beam computed tomography imaging quality possible. Once defined, a clinical feasibility study was initiated. An in-room cone beam computed tomography device is used to acquire intraoperative images after placing the applicator. Repositioning the applicator is thereafter discussed with the surgeon, according to the imaging outcomes, if required. Results: An optimal image quality was achieved with 120-kV voltage, 20-mA current, and a tube current time product of 150 mAs. An additional 0.51 mSv patient exposure was calculated for the entire procedure. The wide dynamic range (-600 HU to +600 HU) of cone beam computed tomography and a 27 HU mean computed tomography values difference between brain tissue and spherical applicator allows distinguishing both structures. In this first in-human experience, the applicator was repositioned after evidencing air gaps, assuring full applicator-to-surface contact. Conclusions: This first in-human procedure confirmed the feasibility of kilovoltage image guided intraoperative radiation therapy in a neurosurgical setting. A prospective study has been initiated and will provide further dosimetric details.

14.
Comput Biol Med ; 173: 108299, 2024 May.
Article in English | MEDLINE | ID: mdl-38537564

ABSTRACT

BACKGROUND: Myocardial ischaemia results from insufficient coronary blood flow. Computed virtual fractional flow reserve (vFFR) allows quantification of proportional flow loss without the need for invasive pressure-wire testing. In the current study, we describe a novel, conductivity model of side branch flow, referred to as 'leak'. This leak model is a function of taper and local pressure, the latter of which may change radically when focal disease is present. This builds upon previous techniques, which either ignore side branch flow, or rely purely on anatomical factors. This study aimed to describe a new, conductivity model of side branch flow and compare this with established anatomical models. METHODS AND RESULTS: The novel technique was used to quantify vFFR, distal absolute flow (Qd) and microvascular resistance (CMVR) in 325 idealised 1D models of coronary arteries, modelled from invasive clinical data. Outputs were compared to an established anatomical model of flow. The conductivity model correlated and agreed with the reference model for vFFR (r = 0.895, p < 0.0001; +0.02, 95% CI 0.00 to + 0.22), Qd (r = 0.959, p < 0.0001; -5.2 mL/min, 95% CI -52.2 to +13.0) and CMVR (r = 0.624, p < 0.0001; +50 Woods Units, 95% CI -325 to +2549). CONCLUSION: Agreement between the two techniques was closest for vFFR, with greater proportional differences seen for Qd and CMVR. The conductivity function assumes vessel taper was optimised for the healthy state and that CMVR was not affected by local disease. The latter may be addressed with further refinement of the technique or inferred from complementary image data. The conductivity technique may represent a refinement of current techniques for modelling coronary side-branch flow. Further work is needed to validate the technique against invasive clinical data.


Subject(s)
Coronary Artery Disease , Coronary Stenosis , Fractional Flow Reserve, Myocardial , Humans , Coronary Vessels , Coronary Angiography/methods , Hemodynamics , Predictive Value of Tests
15.
Environ Int ; 186: 108602, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38555664

ABSTRACT

BACKGROUND: Observational epidemiologic studies provide critical data for the evaluation of the potential effects of environmental, occupational and behavioural exposures on human health. Systematic reviews of these studies play a key role in informing policy and practice. Systematic reviews should incorporate assessments of the risk of bias in results of the included studies. OBJECTIVE: To develop a new tool, Risk Of Bias In Non-randomized Studies - of Exposures (ROBINS-E) to assess risk of bias in estimates from cohort studies of the causal effect of an exposure on an outcome. METHODS AND RESULTS: ROBINS-E was developed by a large group of researchers from diverse research and public health disciplines through a series of working groups, in-person meetings and pilot testing phases. The tool aims to assess the risk of bias in a specific result (exposure effect estimate) from an individual observational study that examines the effect of an exposure on an outcome. A series of preliminary considerations informs the core ROBINS-E assessment, including details of the result being assessed and the causal effect being estimated. The assessment addresses bias within seven domains, through a series of 'signalling questions'. Domain-level judgements about risk of bias are derived from the answers to these questions, then combined to produce an overall risk of bias judgement for the result, together with judgements about the direction of bias. CONCLUSION: ROBINS-E provides a standardized framework for examining potential biases in results from cohort studies. Future work will produce variants of the tool for other epidemiologic study designs (e.g. case-control studies). We believe that ROBINS-E represents an important development in the integration of exposure assessment, evidence synthesis and causal inference.


Subject(s)
Bias , Environmental Exposure , Humans , Environmental Exposure/statistics & numerical data , Follow-Up Studies , Observational Studies as Topic , Cohort Studies , Epidemiologic Studies , Risk Assessment/methods
16.
Age Ageing ; 53(2)2024 02 01.
Article in English | MEDLINE | ID: mdl-38400634

ABSTRACT

BACKGROUND: The Atrial fibrillation Better Care (ABC) pathway is the gold-standard approach to atrial fibrillation (AF) management, but the effect of implementation on health outcomes in care home residents is unknown. OBJECTIVE: To examine associations between ABC pathway adherence and stroke, transient ischaemic attack, cardiovascular hospitalisation, major bleeding, mortality and a composite of all these outcomes in care home residents. METHODS: A retrospective cohort study of older care home residents (≥65 years) in Wales with AF was conducted between 1 January 2003 and 31 December 2018 using the Secure Anonymised Information Linkage Databank. Adherence to the ABC pathway was assessed at care home entry using pre-specified definitions. Cox proportional hazard and competing risk models were used to estimate the risk of health outcomes according to ABC adherence. RESULTS: From 14,493 residents (median [interquartile range] age 87.0 [82.6-91.2] years, 35.2% male) with AF, 5,531 (38.2%) were ABC pathway adherent. Pathway adherence was not significantly associated with risk of the composite outcome (adjusted hazard ratio, 95% confidence interval [CI]: 1.01 [0.97-1.05]). There was a significant independent association observed between ABC pathway adherence and a reduced risk of myocardial infarction (0.70 [0.50-0.98]), but a higher risk of haemorrhagic stroke (1.59 [1.06-2.39]). ABC pathway adherence was not significantly associated with any other individual health outcomes examined. CONCLUSION: An ABC adherent approach in care home residents was not consistently associated with improved health outcomes. Findings should be interpreted with caution owing to difficulties in defining pathway adherence using routinely collected data and an individualised approach is recommended.


Subject(s)
Atrial Fibrillation , Humans , Male , Aged , Aged, 80 and over , Female , Atrial Fibrillation/diagnosis , Atrial Fibrillation/epidemiology , Atrial Fibrillation/therapy , Retrospective Studies , Critical Pathways , Anticoagulants/adverse effects , Information Storage and Retrieval , Outcome Assessment, Health Care
17.
Appl Magn Reson ; 55(1-3): 251-277, 2024.
Article in English | MEDLINE | ID: mdl-38357006

ABSTRACT

Site-directed spin labeling electron paramagnetic resonance (SDSL-EPR) is an established tool for exploring protein structure and dynamics. Although nitroxide side chains attached to a single cysteine via a disulfide linkage are commonly employed in SDSL-EPR, their internal flexibility complicates applications to monitor slow internal motions in proteins and to structure determination by distance mapping. Moreover, the labile disulfide linkage prohibits the use of reducing agents often needed for protein stability. To enable the application of SDSL-EPR to the measurement of slow internal dynamics, new spin labels with hindered internal motion are desired. Here, we introduce a highly ordered nitroxide side chain, designated R9, attached at a single cysteine residue via a non-reducible thioether linkage. The reaction to introduce R9 is highly selective for solvent-exposed cysteine residues. Structures of R9 at two helical sites in T4 Lysozyme were determined by X-ray crystallography and the mobility in helical sequences was characterized by EPR spectral lineshape analysis, Saturation Transfer EPR, and Saturation Recovery EPR. In addition, interspin distance measurements between pairs of R9 residues are reported. Collectively, all data indicate that R9 will be useful for monitoring slow internal structural fluctuations, and applications to distance mapping via dipolar spectroscopy and relaxation enhancement methods are anticipated. Supplementary Information: The online version contains supplementary material available at 10.1007/s00723-023-01618-8.

18.
Syst Rev ; 13(1): 25, 2024 01 12.
Article in English | MEDLINE | ID: mdl-38217041

ABSTRACT

INTRODUCTION: Network meta-analyses (NMAs) have gained popularity and grown in number due to their ability to provide estimates of the comparative effectiveness of multiple treatments for the same condition. The aim of this study is to conduct a methodological review to compile a preliminary list of concepts related to bias in NMAs. METHODS AND ANALYSIS: We included papers that present items related to bias, reporting or methodological quality, papers assessing the quality of NMAs, or method papers. We searched MEDLINE, the Cochrane Library and unpublished literature (up to July 2020). We extracted items related to bias in NMAs. An item was excluded if it related to general systematic review quality or bias and was included in currently available tools such as ROBIS or AMSTAR 2. We reworded items, typically structured as questions, into concepts (i.e. general notions). RESULTS: One hundred eighty-one articles were assessed in full text and 58 were included. Of these articles, 12 were tools, checklists or journal standards; 13 were guidance documents for NMAs; 27 were studies related to bias or NMA methods; and 6 were papers assessing the quality of NMAs. These studies yielded 99 items of which the majority related to general systematic review quality and biases and were therefore excluded. The 22 items we included were reworded into concepts specific to bias in NMAs. CONCLUSIONS: A list of 22 concepts was included. This list is not intended to be used to assess biases in NMAs, but to inform the development of items to be included in our tool.


HIGHLIGHTS: • Our research aimed to develop a preliminary list of concepts related to bias with the goal of developing the first tool for assessing the risk of bias in the results and conclusions of a network meta-analysis (NMA).• We followed the methodology proposed by Whiting (2017) and Sanderson (2007) for creating systematically developed lists of quality items, as a first step in the development of a risk of bias tool for network meta-analysis (RoB NMA Tool).• We included items related to biases in NMAs and excluded items that are equally applicable to all systematic reviews as they are covered by other tools (e.g. ROBIS, AMSTAR 2).• Fifty-seven studies were included generating 99 items, which when screened, yielded 22 included items. These items were then reworded into concepts in preparation for a Delphi process for further vetting by external experts.• A limitation of our study is the challenge in retrieving methods studies as methods collections are not regularly updated.


Subject(s)
Checklist , Humans , Bias , Network Meta-Analysis
19.
Int J Radiat Oncol Biol Phys ; 118(5): 1552-1562, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38199383

ABSTRACT

PURPOSE: After surgical resection of brain metastases (BMs), intraoperative radiation therapy (IORT) provides a promising alternative to adjuvant external beam radiation therapy by enabling superior organ-at-risk preservation, reduction of in-hospital times, and timely admission to subsequent systemic treatments, which increasingly comprise novel targeted immunotherapeutic approaches. We sought to assess the safety and efficacy of IORT in combination with immune checkpoint inhibitors (ICIs) and other targeted therapies (TTs). METHODS AND MATERIALS: In a multicentric approach incorporating individual patient data from 6 international IORT centers, all patients with BMs undergoing IORT were retrospectively assessed for combinatorial treatment with ICIs/TTs and evaluated for toxicity and cumulative rates, including wound dehiscence, radiation necrosis, leptomeningeal spread, local control, distant brain progression (DBP), and estimated overall survival. RESULTS: In total, 103 lesions with a median diameter of 34 mm receiving IORT combined with immunomodulatory systemic treatment or other TTs were included. The median follow-up was 13.2 (range, 1.2-102.4) months, and the median IORT dose was 25 (range, 18-30) Gy prescribed to the applicator surface. There was 1 grade 3 adverse event related to IORT recorded (2.2%). A 4.9% cumulative radiation necrosis rate was observed. The 1-year local control rate was 98.0%, and the 1-year DBP-free survival rate was 60.0%. Median time to DBP was 5.5 (range, 1.0-18.5) months in the subgroup of patients experiencing DBP, and the cumulative leptomeningeal spread rate was 4.9%. The median estimated overall survival was 26 (range, 1.2 to not reached) months with a 1-year survival rate of 74.0%. Early initiation of immunotherapy/TTs was associated with a nonsignificant trend toward improved DBP rate and overall survival. CONCLUSIONS: The combination of ICIs/TTs with IORT for resected BMs does not seem to increase toxicity and yields encouraging local control outcomes in the difficult-to-treat subgroup of larger BMs. Time gaps between surgery and systemic treatment could be shortened or avoided. The definitive role of IORT in local control after BM resection will be defined in a prospective trial.


Subject(s)
Brain Neoplasms , Humans , Prospective Studies , Retrospective Studies , Combined Modality Therapy , Brain Neoplasms/radiotherapy , Brain Neoplasms/secondary , Immunotherapy/adverse effects , Necrosis , Neoplasm Recurrence, Local
20.
Eur J Epidemiol ; 39(3): 257-270, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38183607

ABSTRACT

Fixed-effect meta-analysis has been used to summarize genetic effects on a phenotype across multiple Genome-Wide Association Studies (GWAS) assuming a common underlying genetic effect. Genetic effects may vary with age (or other characteristics), and not allowing for this in a GWAS might lead to bias. Meta-regression models between study heterogeneity and allows effect modification of the genetic effects to be explored. The aim of this study was to explore the use of meta-analysis and meta-regression for estimating age-varying genetic effects on phenotypes. With simulations we compared the performance of meta-regression to fixed-effect and random -effects meta-analyses in estimating (i) main genetic effects and (ii) age-varying genetic effects (SNP by age interactions) from multiple GWAS studies under a range of scenarios. We applied meta-regression on publicly available summary data to estimate the main and age-varying genetic effects of the FTO SNP rs9939609 on Body Mass Index (BMI). Fixed-effect and random-effects meta-analyses accurately estimated genetic effects when these did not change with age. Meta-regression accurately estimated both main genetic effects and age-varying genetic effects. When the number of studies or the age-diversity between studies was low, meta-regression had limited power. In the applied example, each additional minor allele (A) of rs9939609 was inversely associated with BMI at ages 0 to 3, and positively associated at ages 5.5 to 13. Our findings challenge the assumption that genetic effects are consistent across all ages and provide a method for exploring this. GWAS consortia should be encouraged to use meta-regression to explore age-varying genetic effects.


Subject(s)
Genome-Wide Association Study , Polymorphism, Single Nucleotide , Humans , Genome-Wide Association Study/methods , Body Mass Index , Phenotype , Alleles , Alpha-Ketoglutarate-Dependent Dioxygenase FTO
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