Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Nat Methods ; 21(7): 1340-1348, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38918604

RESUMEN

The EMDataResource Ligand Model Challenge aimed to assess the reliability and reproducibility of modeling ligands bound to protein and protein-nucleic acid complexes in cryogenic electron microscopy (cryo-EM) maps determined at near-atomic (1.9-2.5 Å) resolution. Three published maps were selected as targets: Escherichia coli beta-galactosidase with inhibitor, SARS-CoV-2 virus RNA-dependent RNA polymerase with covalently bound nucleotide analog and SARS-CoV-2 virus ion channel ORF3a with bound lipid. Sixty-one models were submitted from 17 independent research groups, each with supporting workflow details. The quality of submitted ligand models and surrounding atoms were analyzed by visual inspection and quantification of local map quality, model-to-map fit, geometry, energetics and contact scores. A composite rather than a single score was needed to assess macromolecule+ligand model quality. These observations lead us to recommend best practices for assessing cryo-EM structures of liganded macromolecules reported at near-atomic resolution.


Asunto(s)
Microscopía por Crioelectrón , Modelos Moleculares , Microscopía por Crioelectrón/métodos , Ligandos , SARS-CoV-2 , COVID-19/virología , Escherichia coli , beta-Galactosidasa/química , beta-Galactosidasa/metabolismo , Conformación Proteica , Reproducibilidad de los Resultados
3.
Phys Eng Sci Med ; 47(2): 539-550, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38451465

RESUMEN

In interventional radiology patient care can be improved by accurately assessing peak skin dose (PSD) from procedures, as it is the main predictor for tissue-reactions such as erythema. Historically, high skin dose procedures performed in radiology departments were almost exclusively planar fluoroscopy. However, with the increase in use of technologies involving repeated or adjacent computed tomography (CT) such as CT fluoroscopy and multi-modality rooms, the peak skin dose delivered by CT needs to be considered. In this paper, a model to estimate the PSD delivered to a patient undergoing CT has been developed to assist in determining the overall PSD. This model relates the PSD to the device-reported CT Dose Index (CTDIvol) by accounting for a variety of CT technique and patient factors. It includes a novel method for estimating dose contributions as a function of patient or phantom size, scanner geometry, and physical measurement of lateral and depth-based beam profiles. Physical measurements of PSD using radiochromic film on several phantoms have been used to determine needed model parameters. The resulting fitted model was found to agree with measured data to a standard deviation of 5.1% for the data used to fit the model, and 6.8% for measurements that were not used for fitting the model. Two methods for adapting the model for specific scanners are provided, one based on local PSD measurements with radiochromic film and another using CTDIvol measurements. The model, when suitably adapted, can accurately assess individual patients' CT PSD. This information can be integrated with radiation exposure data from other modalities, such as planar fluoroscopy, to predict the overall risk of tissue reactions, allowing for more tailored patient care.


Asunto(s)
Fantasmas de Imagen , Dosis de Radiación , Piel , Tomografía Computarizada por Rayos X , Humanos , Piel/diagnóstico por imagen , Relación Dosis-Respuesta en la Radiación
4.
Biosensors (Basel) ; 14(4)2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38667181

RESUMEN

Carbon nanotube (CNT)-based nanocomposites have found applications in making sensors for various types of physiological sensing. However, the sensors' fabrication process is usually complex, multistep, and requires longtime mixing and hazardous solvents that can be harmful to the environment. Here, we report a flexible dry silver (Ag)/CNT/polydimethylsiloxane (PDMS) nanocomposite-based sensor made by a solvent-free, low-temperature, time-effective, and simple approach for electrophysiological recording. By mechanical compression and thermal treatment of Ag/CNT, a connected conductive network of the fillers was formed, after which the PDMS was added as a polymer matrix. The CNTs make a continuous network for electrons transport, endowing the nanocomposite with high electrical conductivity, mechanical strength, and durability. This process is solvent-free and does not require a high temperature or complex mixing procedure. The sensor shows high flexibility and good conductivity. High-quality electroencephalography (EEG) and electrooculography (EOG) were performed using fabricated dry sensors. Our results show that the Ag/CNT/PDMS sensor has comparable skin-sensor interface impedance with commercial Ag/AgCl-coated dry electrodes, better performance for noninvasive electrophysiological signal recording, and a higher signal-to-noise ratio (SNR) even after 8 months of storage. The SNR of electrophysiological signal recording was measured to be 26.83 dB for our developed sensors versus 25.23 dB for commercial Ag/AgCl-coated dry electrodes. Our process of compress-heating the functional fillers provides a universal approach to fabricate various types of nanocomposites with different nanofillers and desired electrical and mechanical properties.


Asunto(s)
Dimetilpolisiloxanos , Nanocompuestos , Nanotubos de Carbono , Plata , Nanocompuestos/química , Nanotubos de Carbono/química , Plata/química , Dimetilpolisiloxanos/química , Electroencefalografía , Conductividad Eléctrica , Técnicas Biosensibles , Humanos , Electrooculografía , Electrodos , Relación Señal-Ruido
5.
Fertil Steril ; 121(5): 806-813, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38253117

RESUMEN

OBJECTIVE: To broadly assess the efficacy of medroxyprogesterone acetate (MPA) for ovulatory suppression during in vitro stimulation compared with gonadotropin-releasing hormone (GnRH) antagonist cycles. DESIGN: Cohort trial. SETTING: A single academic-affiliated private fertility practice. PATIENTS: Patients of all diagnoses aged 18-44 years undergoing autologous in vitro fertilization (IVF) for fertility treatment between 2020 and 2023. INTERVENTIONS: Comparison of MPA vs. antagonist IVF stimulation cycles. MAIN OUTCOME MEASURES: Rates of premature ovulation, oocyte and embryo yield, embryo quality, pregnancy rates, and logistical benefits. RESULTS: Prospective data was collected on 418 patients who underwent MPA protocol ovarian stimulation (MPA group), which was compared with 419 historical control gonadotropin hormone-releasing hormone antagonist cycles (control group). Age was similar between groups (35.6 ± 4.6 vs. 35.7 ± 4.8 years; P = .75). There were no cases of premature ovulation in the MPA group compared with a total of five cases in the control group (0% vs. 1.2%; risk ratio [RR] = 0.09; 95% confidence interval [CI], 0.01, 1.66). No differences were seen between number of oocytes retrieved (14.3 ± 10.2 vs. 14.3 ± 9.7; P = .83), blastocysts (4.9 ± 4.6 vs. 5.0 ± 4.6; P = .89), or euploid blastocysts (2.4 ± 2.6 vs. 2.2 ± 2.4; P = .18) in the MPA vs. control group respectively. Clinical pregnancy rate was similar between groups (70.4% vs. 64.2%; RR = 0.92; 95% CI, 0.72, 1.18). There was no difference in length of IVF stimulation or dose of stimulation medications. Patients in the MPA group saved an average of $491 ± $119 on medications, had an average of one less monitoring visit (4.4 ± 0.9 vs. 5.6 ± 1.1; P<.01), and 5.0 ± 1.2 less injections per cycle. When adjusting for age and ovarian reserve, protocol group (MPA vs. control) did not influence having an embryo available for transfer (76.6% vs. 73.4%; adjusted RR = 1.05; 95% CI, 0.94, 1.14). CONCLUSION: For ovulatory suppression during IVF cycles, MPA was effective at preventing ovulation while demonstrating similar cycle and reproductive outcomes, with the additional benefits of patient cost savings, increased convenience with decreased number of visits, and fewer injections.


Asunto(s)
Fertilización In Vitro , Acetato de Medroxiprogesterona , Inducción de la Ovulación , Índice de Embarazo , Humanos , Femenino , Acetato de Medroxiprogesterona/administración & dosificación , Fertilización In Vitro/métodos , Adulto , Embarazo , Inducción de la Ovulación/métodos , Adulto Joven , Administración Oral , Inhibición de la Ovulación/efectos de los fármacos , Estudios Prospectivos , Fármacos para la Fertilidad Femenina/administración & dosificación , Adolescente , Estudios de Cohortes , Ovulación/efectos de los fármacos , Resultado del Tratamiento , Hormona Liberadora de Gonadotropina/antagonistas & inhibidores , Hormona Liberadora de Gonadotropina/análogos & derivados
6.
Discov Ment Health ; 4(1): 4, 2024 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-38175308

RESUMEN

BACKGROUND: The farming community have high rates of poor mental health, and are relatively 'hard to reach' with mental health services. The aim of this study was therefore to undertake a feasibility RCT, based on two mental health interventions. These were (1) CBT based 'Living Life to the Full for Farming Communities' (LLTTF-F; www.llttf.com ), and (2) a holistic social and emotional support service delivered by the Royal Scottish Agricultural Benevolent Institution (RSABI). The feasibility was supplemented by process evaluation. METHODS: This feasibility study aimed to recruit 40 individuals from the farming community who were experiencing a common health problem defined as a score of > = 8 on PHQ-9. A snowball approach was used to recruit interested individuals who had an association with farming. An initial telephone call screened for eligibility and obtained consent to randomisation to the two specified interventions, or to a thirdly group receiving a combination of both LLTTF-F and 'Social and emotional support'. Participants were permitted to override the randomised option if they expressed a strong preference before the interventions began. RESULTS: Thirty-two participants provided baseline and three-month data. All three interventions showed positive improvements on PHQ-9 scores as follows: the 'combined intervention' mean baseline score was 18.1 compared to 12.0 at 3-month follow-up (mean change 6.1). 'Social and emotional support' mean baseline score was 11.3 compared to 6.7 at 3-month follow-up (mean change 4.6). 'LLTTF-F CBT-based intervention only' mean baseline score was 11.8 compared to 4.5 at 3-month follow-up (mean change 7.3). The retention rate was 81% at three months. In a sub-group of the LLTTF-F CBT-based intervention online materials were supplemented by telephone guided support. This approach received very positive feedback. CONCLUSIONS: Recruitment from the farming community required intense effort, and good engagement can then be retained for at least three months. There is evidence that the interventions used were feasible, and tentative evidence that they had a demonstrable effect on mental wellbeing, with the LLTTFF providing the largest effect on PHQ-9 scores. Trial Registration Number ISRCTN27173711, submitted 25/08/2023, confirmed 22/092023.

7.
Biotechnol Prog ; : e3483, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38856182

RESUMEN

While high-throughput (HT) experimentation and mechanistic modeling have long been employed in chromatographic process development, it remains unclear how these techniques should be used in concert within development workflows. In this work, a process development workflow based on HT experiments and mechanistic modeling was constructed. The integration of HT and modeling approaches offers improved workflow efficiency and speed. This high-throughput in silico (HT-IS) workflow was employed to develop a Capto MMC polishing step for mAb aggregate removal. High-throughput batch isotherm data was first generated over a range of mobile phase conditions and a suite of analytics were employed. Parameters for the extended steric mass action (SMA) isotherm were regressed for the multicomponent system. Model validation was performed using the extended SMA isotherm in concert with the general rate model of chromatography using the CADET modeling software. Here, step elution profiles were predicted for eight RoboColumn runs across a range of ionic strength, pH, and load density. Optimized processes were generated through minimization of a complex objective function based on key process metrics. Processes were evaluated at lab-scale using two feedstocks, differing in composition. The results confirmed that both processes obtained high monomer yield (>85%) and removed ∼ 50 % $$ \sim 50\% $$ of aggregate species. Column simulations were then carried out to determine sensitivity to a wide range of process inputs. Elution buffer pH was found to be the most critical process parameter, followed by resin ionic capacity. Overall, this study demonstrated the utility of the HT-IS workflow for rapid process development and characterization.

8.
Front Cell Dev Biol ; 12: 1422764, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38966426

RESUMEN

Purpose: Extraocular electrical stimulation is known to provide neuroprotection for retinal cells in retinal and optic nerve diseases. Currently, the treatment approach requires patients to set up extraocular electrodes and stimulate potentially weekly due to the lack of an implantable stimulation device. Hence, a minimally-invasive implant was developed to provide chronic electrical stimulation to the retina, potentially improving patient compliance for long-term use. The aim of the present study was to determine the surgical and stimulation safety of this novel device designed for neuroprotective stimulation. Methods: Eight normally sighted adult feline subjects were monocularly implanted in the suprachoroidal space in the peripheral retina for 9-39 weeks. Charge balanced, biphasic, current pulses (100 µA, 500 µs pulse width and 50 pulses/s) were delivered continuously to platinum electrodes for 3-34 weeks. Electrode impedances were measured hourly. Retinal structure and function were assessed at 1-, 2-, 4-, 6- and 8-month using electroretinography, optical coherence tomography and fundus photography. Retina and fibrotic thickness were measured from histological sections. Randomized, blinded histopathological assessments of stimulated and non-stimulated retina were performed. Results: All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. The device position was stable after a post-surgery settling period. Median electrode impedance remained within a consistent range (5-10 kΩ) over time. There was no change in retinal thickness or function relative to baseline and fellow eyes. Fibrotic capsule thickness was equivalent between stimulated and non-stimulated tissue and helps to hold the device in place. There was no scarring, insertion trauma, necrosis, retinal damage or fibroblastic response in any retinal samples from implanted eyes, whilst 19% had a minimal histiocytic response, 19% had minimal to mild acute inflammation and 28% had minimal to mild chronic inflammation. Conclusion: Chronic suprathreshold electrical stimulation of the retina using a minimally invasive device evoked a mild tissue response and no adverse clinical findings. Peripheral suprachoroidal electrical stimulation with an implanted device could potentially be an alternative approach to transcorneal electrical stimulation for delivering neuroprotective stimulation.

9.
PLoS One ; 19(4): e0301175, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38574067

RESUMEN

BACKGROUND: Canonical α/ß T-cell receptors (TCRs) bind to human leukocyte antigen (HLA) displaying antigenic peptides to elicit T cell-mediated cytotoxicity. TCR-engineered T-cell immunotherapies targeting cancer-specific peptide-HLA complexes (pHLA) are generating exciting clinical responses, but owing to HLA restriction they are only able to target a subset of antigen-positive patients. More recently, evidence has been published indicating that naturally occurring α/ß TCRs can target cell surface proteins other than pHLA, which would address the challenges of HLA restriction. In this proof-of-concept study, we sought to identify and engineer so-called HLA-independent TCRs (HiTs) against the tumor-associated antigen mesothelin. METHODS: Using phage display, we identified a HiT that bound well to mesothelin, which when expressed in primary T cells, caused activation and cytotoxicity. We subsequently engineered this HiT to modulate the T-cell response to varying levels of mesothelin on the cell surface. RESULTS: The isolated HiT shows cytotoxic activity and demonstrates killing of both mesothelin-expressing cell lines and patient-derived xenograft models. Additionally, we demonstrated that HiT-transduced T cells do not require CD4 or CD8 co-receptors and, unlike a TCR fusion construct, are not inhibited by soluble mesothelin. Finally, we showed that HiT-transduced T cells are highly efficacious in vivo, completely eradicating xenografted human solid tumors. CONCLUSION: HiTs can be isolated from fully human TCR-displaying phage libraries against cell surface-expressed antigens. HiTs are able to fully activate primary T cells both in vivo and in vitro. HiTs may enable the efficacy seen with pHLA-targeting TCRs in solid tumors to be translated to cell surface antigens.


Asunto(s)
Mesotelina , Neoplasias , Humanos , Linfocitos T CD8-positivos , Receptores de Antígenos de Linfocitos T , Antígenos de Neoplasias/metabolismo , Neoplasias/metabolismo , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Antígenos HLA/metabolismo , Antígenos de Histocompatibilidad Clase II/metabolismo , Péptidos/metabolismo , Antígenos de Histocompatibilidad/metabolismo
10.
Res Sq ; 2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38343795

RESUMEN

The EMDataResource Ligand Model Challenge aimed to assess the reliability and reproducibility of modeling ligands bound to protein and protein/nucleic-acid complexes in cryogenic electron microscopy (cryo-EM) maps determined at near-atomic (1.9-2.5 Å) resolution. Three published maps were selected as targets: E. coli beta-galactosidase with inhibitor, SARS-CoV-2 RNA-dependent RNA polymerase with covalently bound nucleotide analog, and SARS-CoV-2 ion channel ORF3a with bound lipid. Sixty-one models were submitted from 17 independent research groups, each with supporting workflow details. We found that (1) the quality of submitted ligand models and surrounding atoms varied, as judged by visual inspection and quantification of local map quality, model-to-map fit, geometry, energetics, and contact scores, and (2) a composite rather than a single score was needed to assess macromolecule+ligand model quality. These observations lead us to recommend best practices for assessing cryo-EM structures of liganded macromolecules reported at near-atomic resolution.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA