Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Nat Nanotechnol ; 19(3): 354-363, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38082117

RESUMO

Cells secrete numerous bioactive molecules that are essential for the function of healthy organisms. However, scalable methods are needed to link individual cell secretions to their transcriptional state over time. Here, by developing and using secretion-encoded single-cell sequencing (SEC-seq), which exploits hydrogel particles with subnanolitre cavities (nanovials) to capture individual cells and their secretions, we simultaneously measured the secretion of vascular endothelial growth factor A (VEGF-A) and the transcriptome for thousands of individual mesenchymal stromal cells. Our data indicate that VEGF-A secretion is heterogeneous across the cell population and is poorly correlated with the VEGFA transcript level. The highest VEGF-A secretion occurs in a subpopulation of mesenchymal stromal cells characterized by a unique gene expression signature comprising a surface marker, interleukin-13 receptor subunit alpha 2 (IL13RA2), which allowed the enrichment of this subpopulation. SEC-seq enables the identification of gene signatures linked to specific secretory states, facilitating mechanistic studies, the isolation of secretory subpopulations and the development of means to modulate cellular secretion.


Assuntos
Células-Tronco Mesenquimais , Fator A de Crescimento do Endotélio Vascular , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Transcriptoma , Células-Tronco Mesenquimais/metabolismo
2.
PLoS One ; 19(6): e0303894, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38941338

RESUMO

OBJECTIVE: This study began as a single-blind randomized controlled trial (RCT) to investigate the efficacy and safety of electroconvulsive therapy (ECT) for severe treatment-refractory agitation in advanced dementia. The aims are to assess agitation reduction using the Cohen-Mansfield Agitation Inventory (CMAI), evaluate tolerability and safety outcomes, and explore the long-term stability of agitation reduction and global functioning. Due to challenges encountered during implementation, including recruitment obstacles and operational difficulties, the study design was modified to an open-label format and other protocol amendments were implemented. METHODS: Initially, the RCT randomized participants 1:1 to either ECT plus usual care or simulated ECT plus usual care (S-ECT) groups. As patients were enrolled, data were collected from both ECT and simulated ECT (S-ECT) patients. The study now continues in an open-label study design where all patients receive actual ECT, reducing the targeted sample size from 200 to 50 participants. RESULTS: Study is ongoing and open to enrollment. CONCLUSION: The transition of the ECT-AD study design from an RCT to open-label design exemplifies adaptive research methodologies in response to real-world challenges. Data from both the RCT and open-label phases of the study will provide a unique perspective on the role of ECT in managing severe treatment-refractory agitation in dementia, potentially influencing future clinical practices and research approaches.


Assuntos
Demência , Eletroconvulsoterapia , Agitação Psicomotora , Humanos , Eletroconvulsoterapia/métodos , Agitação Psicomotora/terapia , Demência/terapia , Demência/complicações , Método Simples-Cego , Feminino , Masculino , Resultado do Tratamento , Idoso , Comportamento Motor Aberrante na Demência
3.
bioRxiv ; 2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36711480

RESUMO

Cells secrete numerous bioactive molecules essential for the function of healthy organisms. However, there are no scalable methods to link individual cell secretions to their transcriptional state. By developing and using secretion encoded single-cell sequencing (SEC-seq), which exploits hydrogel nanovials to capture individual cells and their secretions, we simultaneously measured the secretion of vascular endothelial growth factor A (VEGF-A) and the transcriptome for thousands of individual mesenchymal stromal cells (MSCs). We found that VEGF-A secretion is heterogeneous across the cell population and lowly correlated with the VEGFA transcript level. While there is a modest population-wide increase in VEGF-A secretion by hypoxic induction, highest VEGF-A secretion across normoxic and hypoxic culture conditions occurs in a subpopulation of MSCs characterized by a unique gene expression signature. Taken together, SEC-seq enables the identification of specific genes involved in the control of secretory states, which may be exploited for developing means to modulate cellular secretion for disease treatment.

4.
Future Microbiol ; 17: 89-97, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34915735

RESUMO

Background: The main aim of this study was to assess the efficacy of advanced respiratory support (ARS) for acute respiratory failure in do-not-attempt cardiopulmonary resuscitation order (DNACPR) COVID-19 patients. Methods: In this single-center study, the impact of different types of ARS modality, PaO2/FiO2 (PF) ratio, clinical frailty score (CFS) and 4C score on mortality was evaluated. Results: There was no significant difference in age, type of ARS modality, PF ratio and 4C scores between those who died and those who survived. Overall survival rates/hospital discharge of patients still requiring ARS at 5 and 7 days post admission were 20 and 17%, respectively. Conclusion: Our study showed that ARS can be a useful tool in frail, elderly and high-risk COVID-19 patients irrespective of high 4C mortality score.


Assuntos
COVID-19 , Fragilidade , Insuficiência Respiratória , COVID-19/mortalidade , COVID-19/terapia , Humanos , Insuficiência Respiratória/terapia , Ordens quanto à Conduta (Ética Médica)
5.
Cureus ; 13(6): e15511, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34268041

RESUMO

Introduction An acute upper gastrointestinal bleed (AUGIB) is a fatal and prevalent medical emergency if not appropriately treated in a timely fashion. Aim The aim of this project was to compare the knowledge and skills of the participants in managing upper gastrointestinal bleeding (UGIB) before and after a one-day UGIB haemostasis course. Methods A one-day haemostasis course in line with the British Society of Gastroenterology's Endoscopy Quality Improvement Project Initiative was organised at the Sheffield Teaching Hospitals National Health Service (NHS) Trust. The course included lectures on UGIB and its management, which was followed by hands-on training on adrenaline injection, variceal banding, clip placement, thermal therapy, Hemospray® use, Sengstaken-Blakemore tube placement, and Danis stent placement via porcine or plastic models. Pre- and post-course feedback questionnaires consisting of self-assessed ratings related to knowledge, skills, and behaviour relevant to UGIB were offered to all delegates. Two-tailed Wilcoxon signed-rank test was used to compare the results. Results A total of 36 individuals attended the course. Delegates had an average endoscopy procedure count of 583. The cohort ranged from different fields of medicine, including gastroenterology consultants and junior doctors. Ten of the delegates were Joint Advisory Group-certified in upper gastrointestinal endoscopy. Feedback datasheets were returned by 22 delegates. Significant improvements were reported post-course (p < 0.001), especially in the hands-on and behavioural areas. Conclusion Overall, there was a significant improvement in the knowledge, procedural skills, and confidence of the delegates in the management of an AUGIB post-course. We recommend not only to include this course in gastrointestinal training but also to conduct a course such as this for consultants and junior doctors who wish to undergo gastrointestinal training in the future.

6.
Transl Psychiatry ; 11(1): 516, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34625534

RESUMO

Electroconvulsive therapy (ECT) is of the most effective treatments available for treatment-resistant depression, yet it is underutilized in part due to its reputation of causing cognitive side effects in a significant number of patients. Despite intensive neuroimaging research on ECT in the past two decades, the underlying neurobiological correlates of cognitive side effects remain elusive. Because the primary ECT-related cognitive deficit is memory impairment, it has been suggested that the hippocampus may play a crucial role. In the current study, we investigated 29 subjects with longitudinal MRI and detailed neuropsychological testing in two independent cohorts (N = 15/14) to test if volume changes were associated with cognitive side effects. The two cohorts underwent somewhat different ECT study protocols reflected in electrode placements and the number of treatments. We used longitudinal freesurfer algorithms (6.0) to obtain a bias-free estimate of volume changes in the hippocampus and tested its relationship with neurocognitive score changes. As an exploratory analysis and to evaluate how specific the effects were to the hippocampus, we also calculated this relationship in 41 other areas. In addition, we also analyzed cognitive data from a group of healthy volunteers (N = 29) to assess practice effects. Our results supported the hypothesis that hippocampus enlargement was associated with worse cognitive outcomes, and this result was generalizable across two independent cohorts with different diagnoses, different electrode placements, and a different number of ECT sessions. We found, in both cohorts, that treatment robustly increased the volume size of the hippocampus (Cohort 1: t = 5.07, Cohort 2: t = 4.82; p < 0.001), and the volume increase correlated with the neurocognitive T-score change. (Cohort 1: r = -0.68, p = 0.005; Cohort 2: r = -0.58; p = 0.04). Overall, our research indicates that novel treatment methods serving to avoid hippocampal volume increase may result in a better side effect profile.


Assuntos
Transtornos Cognitivos , Eletroconvulsoterapia , Cognição , Hipocampo/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética
7.
Biochim Biophys Acta Biomembr ; 1863(12): 183758, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34480878

RESUMO

Styrene maleic acid (SMA) polymers have proven to be very successful for the extraction of membrane proteins, forming SMA lipid particles (SMALPs), which maintain a lipid bilayer around the membrane protein. SMALP-encapsulated membrane proteins can be used for functional and structural studies. The SMALP approach allows retention of important protein-annular lipid interactions, exerts lateral pressure, and offers greater stability than traditional detergent solubilisation. However, SMA polymer does have some limitations, including a sensitivity to divalent cations and low pH, an absorbance spectrum that overlaps with many proteins, and possible restrictions on protein conformational change. Various modified polymers have been developed to try to overcome these challenges, but no clear solution has been found. A series of partially-esterified variants of SMA (SMA 2625, SMA 1440 and SMA 17352) has previously been shown to be highly effective for solubilisation of plant and cyanobacterial thylakoid membranes. It was hypothesised that the partial esterification of maleic acid groups would increase tolerance to divalent cations. Therefore, these partially-esterified polymers were tested for the solubilisation of lipids and membrane proteins, and their tolerance to magnesium ions. It was found that all partially esterified polymers were capable of solubilising and purifying a range of membrane proteins, but the yield of protein was lower with SMA 1440, and the degree of purity was lower for both SMA 1440 and SMA 17352. SMA 2625 performed comparably to SMA 2000. SMA 1440 also showed an increased sensitivity to divalent cations. Thus, it appears the interactions between SMA and divalent cations are more complex than proposed and require further investigation.


Assuntos
Lipídeos/química , Maleatos/química , Proteínas de Membrana/isolamento & purificação , Poliestirenos/química , Tilacoides/química , Cátions , Cianobactérias/química , Esterificação , Bicamadas Lipídicas/química , Proteínas de Membrana/química , Conformação Proteica , Tilacoides/genética
8.
Lupus Sci Med ; 6(1): e000327, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31413849

RESUMO

OBJECTIVE: Resting Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) brain imaging and neuropsychological testing were used to investigate the usefulness of a spatial navigation task (SNT) as a performance benchmark for cognitive impairment related to anti-N-methyl D-aspartate (anti-NMDA) receptor antibodies (DNRAb) in SLE. METHODS: Neuropsychological assessments, including a desktop 3-D virtual SNT, were performed on 19 SLE participants and 9 healthy control (HC) subjects. SLE participants had stable disease activity and medication doses and no history of neuropsychiatric illness or current use of mind-altering medications. Resting FDG-PET scans were obtained on all SLE participants and compared with a historical set from 25 age-matched and sex-matched HCs. Serum DNRAb titres were measured by ELISA. RESULTS: 11/19 (58%) of SLE participants failed to complete the SNT (SNT-) compared with 2/9 (22%) of HCs. Compared with 7/9 (78%) in HCs, only 2/9 (22%; p=0.037) of SLE participants with high serum DNRAb titres completed the SNT, in contrast to 6/10 (60%; p=0.810) in SLE participants with low DNRAb titres. Voxel-wise comparison of FDG-PET scans between the 8 SLE participants successfully completing the SNT task (SNT+) and the 11 SNT- SLE participants revealed increased metabolism in the SNT+ participants (p<0.001) in the left anterior putamen/caudate, right anterior putamen, left prefrontal cortex (BA 9), right prefrontal cortex (BA 9/10) and left lateral and medial frontal cortex (BA 8). Compared with HCs, the SNT+ group demonstrated increased metabolism in all regions (p<0.02) except for the right prefrontal cortex (BA 9), whereas the SNT- group demonstrated either significantly decreased or similar metabolism in these seven regions. CONCLUSIONS: SNT performance is associated with serum DNRAb titres and resting glucose metabolism in the anterior putamen/caudate and frontal cortex, suggesting compensatory neural recruitment in SNT-associated regions is necessary for successful completion of the task. The SNT therefore has potential for use as a marker for SLE-mediated cognitive impairment.

9.
JCI Insight ; 4(1)2019 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-30626758

RESUMO

To address challenges in the diagnosis of cognitive dysfunction (CD) related to systemic lupus erythematosus-associated (SLE-associated) autoimmune mechanisms rather than confounding factors, we employed an integrated approach, using resting-state functional (FDG-PET) and structural (diffusion tensor imaging [DTI]) neuroimaging techniques and cognitive testing, in adult SLE patients with quiescent disease and no history of neuropsychiatric illness. We identified resting hypermetabolism in the sensorimotor cortex, occipital lobe, and temporal lobe of SLE subjects, in addition to validation of previously published resting hypermetabolism in the hippocampus, orbitofrontal cortex, and putamen/GP/thalamus. Regional hypermetabolism demonstrated abnormal interregional metabolic correlations, associated with impaired cognitive performance, and was stable over 15 months. DTI analyses demonstrated 4 clusters of decreased microstructural integrity in white matter tracts adjacent to hypermetabolic regions and significantly diminished connecting tracts in SLE subjects. Decreased microstructural integrity in the parahippocampal gyrus correlated with impaired spatial memory and increased serum titers of DNRAb, a neurotoxic autoantibody associated with neuropsychiatric lupus. These findings of regional hypermetabolism, associated with decreased microstructural integrity and poor cognitive performance and not associated with disease duration, disease activity, medications, or comorbid disease, suggest that this is a reproducible, stable marker for SLE-associated CD that may be may be used for early disease detection and to discriminate between groups, evaluate response to treatment strategies, or assess disease progression.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa