Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 97
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nature ; 631(8021): 544-548, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39020036

RESUMEN

A long-standing challenge is how to formulate proteins and vaccines to retain function during storage and transport and to remove the burdens of cold-chain management. Any solution must be practical to use, with the protein being released or applied using clinically relevant triggers. Advanced biologic therapies are distributed cold, using substantial energy, limiting equitable distribution in low-resource countries and placing responsibility on the user for correct storage and handling. Cold-chain management is the best solution at present for protein transport but requires substantial infrastructure and energy. For example, in research laboratories, a single freezer at -80 °C consumes as much energy per day as a small household1. Of biological (protein or cell) therapies and all vaccines, 75% require cold-chain management; the cost of cold-chain management in clinical trials has increased by about 20% since 2015, reflecting this complexity. Bespoke formulations and excipients are now required, with trehalose2, sucrose or polymers3 widely used, which stabilize proteins by replacing surface water molecules and thereby make denaturation thermodynamically less likely; this has enabled both freeze-dried proteins and frozen proteins. For example, the human papilloma virus vaccine requires aluminium salt adjuvants to function, but these render it unstable against freeze-thaw4, leading to a very complex and expensive supply chain. Other ideas involve ensilication5 and chemical modification of proteins6. In short, protein stabilization is a challenge with no universal solution7,8. Here we designed a stiff hydrogel that stabilizes proteins against thermal denaturation even at 50 °C, and that can, unlike present technologies, deliver pure, excipient-free protein by mechanically releasing it from a syringe. Macromolecules can be loaded at up to 10 wt% without affecting the mechanism of release. This unique stabilization and excipient-free release synergy offers a practical, scalable and versatile solution to enable the low-cost, cold-chain-free and equitable delivery of therapies worldwide.


Asunto(s)
Almacenaje de Medicamentos , Hidrogeles , Desnaturalización Proteica , Estabilidad Proteica , Proteínas , Jeringas , Humanos , Excipientes , Liofilización , Hidrogeles/química , Proteínas/administración & dosificación , Proteínas/química , Proteínas/economía , Trehalosa , Congelación , Refrigeración , Vacunas contra Papillomavirus/química , Almacenaje de Medicamentos/economía , Almacenaje de Medicamentos/métodos
2.
New Phytol ; 243(3): 909-921, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38877705

RESUMEN

Leaf decomposition varies widely across temperate forests, shaped by factors like litter quality, climate, soil properties, and decomposers, but forest heterogeneity may mask local tree influences on decomposition and litter-associated microbiomes. We used a 24-yr-old common garden forest to quantify local soil conditioning impacts on decomposition and litter microbiology. We introduced leaf litter bags from 10 tree species (5 arbuscular mycorrhizal; 5 ectomycorrhizal) to soil plots conditioned by all 10 species in a full-factorial design. After 6 months, we assessed litter mass loss, C/N content, and bacterial and fungal composition. We hypothesized that (1) decomposition and litter-associated microbiome composition would be primarily shaped by the mycorrhizal type of litter-producing trees, but (2) modified significantly by underlying soil, based on mycorrhizal type of the conditioning trees. Decomposition and, to a lesser extent, litter-associated microbiome composition, were primarily influenced by the mycorrhizal type of litter-producing trees. Interestingly, however, underlying soils had a significant secondary influence, driven mainly by tree species, not mycorrhizal type. This secondary influence was strongest under trees from the Pinaceae. Temperate trees can locally influence underlying soil to alter decomposition and litter-associated microbiology. Understanding the strength of this effect will help predict biogeochemical responses to forest compositional change.


Asunto(s)
Microbiota , Micorrizas , Hojas de la Planta , Microbiología del Suelo , Suelo , Especificidad de la Especie , Árboles , Árboles/microbiología , Suelo/química , Hojas de la Planta/microbiología , Hojas de la Planta/metabolismo , Micorrizas/fisiología , Clima
3.
BMC Psychiatry ; 24(1): 576, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39180055

RESUMEN

BACKGROUND: Major depressive disorder (MDD) is a disabling mental illness that can affect all aspects of daily life and is a leading cause of healthcare resource utilisation (HCRU). AIMS: We aimed to characterise patients with MDD with moderate-to-high-suicide-intent, compare their HCRU to patients with MDD without moderate-to-high-suicide-intent, and better understand their patient pathways. METHODS: This retrospective cohort study used data collected from primary care electronic health records from Clinical Practice Research Datalink (CPRD), linked to Hospital Episode Statistics, Mental Health Services Data Set, and Office for National Statistics in England. Adults diagnosed with ≥ 1 MDD diagnosis between 04/2007 and 11/2015 were categorised by suicide intent. RESULTS: 307,476 patients with MDD were included (294,259 patients without moderate-to-high-suicide-intent and 13,217 with moderate-to-high-suicide-intent). Patients with MDD with moderate-to-high-suicide-intent were younger on average (39.0 vs. 44.8 years) and included a lower percentage of females (58% vs. 65%) compared to patients without moderate-to-high-suicide-intent. HCRU was greater among patients with moderate-to-high-suicide-intent than patients without moderate-to-high-suicide-intent during the first follow-up year for general practitioner consultations (38.5 vs. 29.4), psychiatric outpatient visits (1.5 vs. 0.1), psychiatrist visits (3.6 vs. 0.3), emergency visits (1.5 vs. 0.3), and hospitalisations (86% vs. 26%). Overall, 56% of patients with moderate-to-high-suicide-intent had an antidepressant prescription within 30 days from the initial moderate-to-high-suicide-intent. CONCLUSIONS: Patients with MDD and moderate-to-high-suicide-intent were younger, included more males and incurred greater HCRU than those without moderate-to-high-suicide-intent. These results suggest a greater need for effective medical care and appropriate treatments for patients with moderate-to-high-suicide-intent, which could help reduce associated symptoms, mortality, and HCRU.


Asunto(s)
Trastorno Depresivo Mayor , Aceptación de la Atención de Salud , Humanos , Femenino , Masculino , Trastorno Depresivo Mayor/epidemiología , Adulto , Inglaterra , Estudios Retrospectivos , Persona de Mediana Edad , Aceptación de la Atención de Salud/estadística & datos numéricos , Servicios de Salud Mental/estadística & datos numéricos , Intento de Suicidio/estadística & datos numéricos , Adulto Joven , Atención Primaria de Salud/estadística & datos numéricos , Adolescente , Anciano , Hospitalización/estadística & datos numéricos , Ideación Suicida
4.
Plant Cell Environ ; 46(12): 3919-3932, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37675977

RESUMEN

Traditionally, fine roots were grouped using arbitrary size categories, rarely capturing the heterogeneity in physiology, morphology and functionality among different fine root orders. Fine roots with different functional roles are rarely separated in microbiome-focused studies and may result in confounding microbial signals and host-filtering across different root microbiome compartments. Using a 26-year-old common garden, we sampled fine roots from four temperate tree species that varied in root morphology and sorted them into absorptive and transportive fine roots. The rhizoplane and rhizosphere were characterized using 16S rRNA gene and internal transcribed spacer region amplicon sequencing and shotgun metagenomics for the rhizoplane to identify potential microbial functions. Fine roots were subject to metabolomics to spatially characterize resource availability. Both fungi and bacteria differed according to root functional type. We observed additional differences between the bacterial rhizoplane and rhizosphere compartments for absorptive but not transportive fine roots. Rhizoplane bacteria, as well as the root metabolome and potential microbial functions, differed between absorptive and transportive fine roots, but not the rhizosphere bacteria. Functional differences were driven by sugar transport, peptidases and urea transport. Our data highlights the importance of root function when examining root-microbial relationships, emphasizing different host selective pressures imparted on different root microbiome compartments.


Asunto(s)
Bacterias , Raíces de Plantas , Raíces de Plantas/microbiología , ARN Ribosómico 16S/genética , Bacterias/genética , Rizosfera , Hongos , Microbiología del Suelo
5.
Telemed J E Health ; 28(9): 1379-1385, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35007435

RESUMEN

Introduction: Since the onset of the COVID-19 pandemic, there has been rapid expansion in the use of telehealth. As a result, many providers who had no prior experience using telehealth are now using it to provide patient care. The goal of this study was to survey health care providers on a wide range of telehealth topics including their experiences examining and connecting with patients digitally, identifying which types of patients may be best suited to telehealth, and identifying technical and logistical areas for improvement when using telehealth. Methods: Physicians and advanced practice providers (n = 944) at a large midwestern academic system were invited to complete an anonymous online survey during a 2-week period in October 2020. Results: Surveys, completed and analyzed (n = 178), indicated 86.6% of respondents felt confident in their clinical assessment, and 86.1% felt they formed an adequate personal connection with the patient in the majority of telehealth visits. A majority (58.5%) of providers felt telehealth was not effective for new patients, but 83% of providers felt it was effective for providing care to established patients. Respondents identified several areas for technological improvement including issues with video (27.5%) and audio (16.8%) quality. In 24.4% of visits, these technology issues were severe enough providers needed to convert an audiovisual appointment to telephone. Conclusions: Provider experience with telehealth has largely been positive at our institution. Although telehealth may not be appropriate for new patients, providers did feel it was an effective means of providing care for established patients. To continue improving the quality of telehealth, a multiteam approach should be considered, including members of technology and clinical operations teams working closely with those providers experienced in telehealth.


Asunto(s)
COVID-19 , Telemedicina , COVID-19/epidemiología , Personal de Salud , Humanos , Pandemias , Encuestas y Cuestionarios
6.
J Nurs Manag ; 30(8): 4472-4479, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36326282

RESUMEN

AIM: The aim of this study is to explore the influence of a talent management scheme in an English National Health Service (NHS) Trust on registered nurses' retention intentions. BACKGROUND: The retention of nurses is a global challenge, and talent management initiatives can play a role in improving retention. Talent management in its broadest sense is a way in which an organization recruits and retains the workforce that it needs to optimize the services it delivers. METHODS: In this qualitative study, eight in-depth semi-structured interviews were conducted with registered nurses who had participated in a talent management initiative, at an English acute NHS Trust. Data were collected in July 2019. RESULTS: The talent management initiative influenced positive retention intentions. Retention of nurses was facilitated by the creation of networks and networking. CONCLUSION: Networks and networking can be viewed as a form of social capital, which was a facilitating factor for positive retention intentions for nurses. IMPLICATIONS FOR NURSING MANAGEMENT: Talent management initiatives for nurses should be developed and directed to include the building of networks and networking to enable development of social capital. Although this talent management scheme is within the NHS, the issue of nursing retention is global. Application of learning from this paper to other health care systems is possible.


Asunto(s)
Intención , Enfermeras y Enfermeros , Humanos , Medicina Estatal , Atención a la Salud , Recursos Humanos
7.
J Neurosci ; 40(34): 6536-6556, 2020 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-32669356

RESUMEN

The dendritic arbor of neurons constrains the pool of available synaptic partners and influences the electrical integration of synaptic currents. Despite these critical functions, our knowledge of the dendritic structure of cortical neurons during early postnatal development and how these dendritic structures are modified by visual experience is incomplete. Here, we present a large-scale dataset of 849 3D reconstructions of the basal arbor of pyramidal neurons collected across early postnatal development in visual cortex of mice of either sex. We found that the basal arbor grew substantially between postnatal day 7 (P7) and P30, undergoing a 45% increase in total length. However, the gross number of primary neurites and dendritic segments was largely determined by P7. Growth from P7 to P30 occurred primarily through extension of dendritic segments. Surprisingly, comparisons of dark-reared and typically reared mice revealed that a net gain of only 15% arbor length could be attributed to visual experience; most growth was independent of experience. To examine molecular contributions, we characterized the role of the activity-regulated small GTPase Rem2 in both arbor development and the maintenance of established basal arbors. We showed that Rem2 is an experience-dependent negative regulator of dendritic segment number during the visual critical period. Acute deletion of Rem2 reduced directionality of dendritic arbors. The data presented here establish a highly detailed, quantitative analysis of basal arbor development that we believe has high utility both in understanding circuit development as well as providing a framework for computationalists wishing to generate anatomically accurate neuronal models.SIGNIFICANCE STATEMENT Dendrites are the sites of the synaptic connections among neurons. Despite their importance for neural circuit function, only a little is known about the postnatal development of dendritic arbors of cortical pyramidal neurons and the influence of experience. Here we show that the number of primary basal dendritic arbors is already established before eye opening, and that these arbors primarily grow through lengthening of dendritic segments and not through addition of dendritic segments. Surprisingly, visual experience has a modest net impact on overall arbor length (15%). Experiments in KO animals revealed that the gene Rem2 is positive regulator of dendritic length and a negative regulator of dendritic segments.


Asunto(s)
Dendritas/fisiología , Células Piramidales/fisiología , Corteza Visual/crecimiento & desarrollo , Corteza Visual/fisiología , Animales , Femenino , Masculino , Ratones Noqueados , Proteínas de Unión al GTP Monoméricas/genética , Proteínas de Unión al GTP Monoméricas/fisiología , Neuritas/fisiología , Células Piramidales/citología , Corteza Visual/citología
8.
Am J Hum Genet ; 103(4): 621-630, 2018 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-30290154

RESUMEN

Aberrant activation or inhibition of potassium (K+) currents across the plasma membrane of cells has been causally linked to altered neurotransmission, cardiac arrhythmias, endocrine dysfunction, and (more rarely) perturbed developmental processes. The K+ channel subfamily K member 4 (KCNK4), also known as TRAAK (TWIK-related arachidonic acid-stimulated K+ channel), belongs to the mechano-gated ion channels of the TRAAK/TREK subfamily of two-pore-domain (K2P) K+ channels. While K2P channels are well known to contribute to the resting membrane potential and cellular excitability, their involvement in pathophysiological processes remains largely uncharacterized. We report that de novo missense mutations in KCNK4 cause a recognizable syndrome with a distinctive facial gestalt, for which we propose the acronym FHEIG (facial dysmorphism, hypertrichosis, epilepsy, intellectual disability/developmental delay, and gingival overgrowth). Patch-clamp analyses documented a significant gain of function of the identified KCNK4 channel mutants basally and impaired sensitivity to mechanical stimulation and arachidonic acid. Co-expression experiments indicated a dominant behavior of the disease-causing mutations. Molecular dynamics simulations consistently indicated that mutations favor sealing of the lateral intramembrane fenestration that has been proposed to negatively control K+ flow by allowing lipid access to the central cavity of the channel. Overall, our findings illustrate the pleiotropic effect of dysregulated KCNK4 function and provide support to the hypothesis of a gating mechanism based on the lateral fenestrations of K2P channels.


Asunto(s)
Activación del Canal Iónico/genética , Mutación/genética , Trastornos del Neurodesarrollo/genética , Canales de Potasio/genética , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Simulación de Dinámica Molecular
9.
Bioconjug Chem ; 31(10): 2392-2403, 2020 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-32951418

RESUMEN

Glycomaterials display enhanced binding affinity to carbohydrate-binding proteins due to the nonlinear enhancement associated with the cluster glycoside effect. Gold nanoparticles bearing glycans have attracted significant interest in particular. This is due to their versatility, their highly tunable gold cores (size and shape), and their application in biosensors and diagnostic tools. However, conjugating glycans onto these materials can be challenging, necessitating either multiple protecting group manipulations or the use of only simple glycans. This results in limited structural diversity compared to glycoarrays which can include hundreds of glycans. Here we report a method to generate glyconanoparticles from unprotected glycans by conjugation to polymer tethers bearing terminal amino-oxy groups, which are then immobilized onto gold nanoparticles. Using an isotope-labeled glycan, the efficiency of this reaction was probed in detail to confirm conjugation, with 25% of end-groups being functionalized, predominantly in the ring-closed form. Facile post-glycosylation purification is achieved by simple centrifugation/washing cycles to remove excess glycan and polymer. This streamlined synthetic approach may be particularly useful for the preparation of glyconanoparticle libraries using automation, to identify hits to be taken forward using more conventional synthetic methods. Exemplar lectin-binding studies were undertaken to confirm the availability of the glycans for binding and show this is a powerful tool for rapid assessment of multivalent glycan binding.


Asunto(s)
Oro/química , Nanopartículas del Metal/química , Polímeros/química , Polisacáridos/química , Aminación , Ligandos , Nanotecnología , Polímeros/síntesis química , Polisacáridos/síntesis química
10.
Biomacromolecules ; 21(4): 1604-1612, 2020 04 13.
Artículo en Inglés | MEDLINE | ID: mdl-32191036

RESUMEN

During influenza infection, hemagglutinins (HAs) on the viral surface bind to sialic acids on the host cell's surface. While all HAs bind sialic acids, human influenza targets terminal α2,6 sialic acids and avian influenza targets α2,3 sialic acids. For interspecies transmission (zoonosis), HA must mutate to adapt to these differences. Here, multivalent gold nanoparticles bearing either α2,6- or α2,3-sialyllactosamine have been developed to interrogate a panel of HAs from pathogenic human, low pathogenic avian, and other species' influenza. This method exploits the benefits of multivalent glycan presentation compared to monovalent presentation to increase affinity and investigate how multivalency affects selectivity. Using a library-orientated approach, parameters including polymer coating and core diameter were optimized for maximal binding and specificity were probed using galactosylated particles and a panel of biophysical techniques [ultraviolet-visible spectroscopy, dynamic light scattering, and biolayer interferometry]. The optimized particles were then functionalized with sialyllactosamine and their binding analyzed against a panel of HAs derived from pathogenic influenza strains including low pathogenic avian strains. This showed significant specificity crossover, which is not observed in monovalent formats, with binding of avian HAs to human sialic acids and vice versa in agreement with alternate assay formats. These results demonstrate that precise multivalent presentation is essential to dissect the interactions of HAs and may aid the discovery of tools for disease and zoonosis transmission.


Asunto(s)
Gripe Humana , Nanopartículas del Metal , Animales , Oro , Hemaglutininas , Humanos , Polímeros
11.
BMC Evol Biol ; 19(1): 141, 2019 07 11.
Artículo en Inglés | MEDLINE | ID: mdl-31296160

RESUMEN

BACKGROUND: The LysM receptor-like kinases (LysM-RLKs) are important to both plant defense and symbiosis. Previous studies described three clades of LysM-RLKs: LysM-I/LYKs (10+ exons per gene and containing conserved kinase residues), LysM-II/LYRs (1-5 exons per gene, lacking conserved kinase residues), and LysM-III (two exons per gene, with a kinase unlike other LysM-RLK kinases and restricted to legumes). LysM-II gene products are presumably not functional as conventional receptor kinases, but several are known to operate in complexes with other LysM-RLKs. One aim of our study was to take advantage of recently mapped wild tomato transcriptomes to evaluate the evolutionary history of LysM-RLKs within and between species. The second aim was to place these results into a broader phylogenetic context by integrating them into a sequence analysis of LysM-RLKs from other functionally well-characterized model plant species. Furthermore, we sought to assess whether the Group III LysM-RLKs were restricted to the legumes or found more broadly across Angiosperms. RESULTS: Purifying selection was found to be the prevailing form of natural selection within species at LysM-RLKs. No signatures of balancing selection were found in species-wide samples of two wild tomato species. Most genes showed a greater extent of purifying selection in their intracellular domains, with the exception of SlLYK3 which showed strong purifying selection in both the extracellular and intracellular domains in wild tomato species. The phylogenetic analysis did not reveal a clustering of microbe/functional specificity to groups of closely related proteins. We also discovered new putative LysM-III genes in a range of Rosid species, including Eucalyptus grandis. CONCLUSIONS: The LysM-III genes likely originated before the divergence of E. grandis from other Rosids via a fusion of a Group II LysM triplet and a kinase from another RLK family. SlLYK3 emerges as an especially interesting candidate for further study due to the high protein sequence conservation within species, its position in a clade of LysM-RLKs with distinct LysM domains, and its close evolutionary relationship with LYK3 from Arabidopsis thaliana.


Asunto(s)
Evolución Molecular , Proteínas Serina-Treonina Quinasas/genética , Solanum lycopersicum/enzimología , Solanum lycopersicum/genética , Secuencia de Aminoácidos , Filogenia , Dominios Proteicos , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Selección Genética , Transcriptoma
12.
J Neurophysiol ; 120(2): 854-866, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29766767

RESUMEN

Circuit operations are determined jointly by the properties of the circuit elements and the properties of the connections among these elements. In the nervous system, neurons exhibit diverse morphologies and branching patterns, allowing rich compartmentalization within individual cells and complex synaptic interactions among groups of cells. In this review, we summarize work detailing how neuronal morphology impacts neural circuit function. In particular, we consider example neurons in the retina, cerebral cortex, and the stomatogastric ganglion of crustaceans. We also explore molecular coregulators of morphology and circuit function to begin bridging the gap between molecular and systems approaches. By identifying motifs in different systems, we move closer to understanding the structure-function relationships that are present in neural circuits.


Asunto(s)
Corteza Cerebral/citología , Corteza Cerebral/fisiología , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/fisiología , Neuronas Retinianas/citología , Neuronas Retinianas/fisiología , Animales , Corteza Cerebral/crecimiento & desarrollo , Crustáceos/citología , Crustáceos/fisiología , Dendritas , Ganglios de Invertebrados/crecimiento & desarrollo , Humanos , Vías Nerviosas/citología , Vías Nerviosas/fisiología , Neuronas/citología , Neuronas/fisiología , Estrigiformes/anatomía & histología , Estrigiformes/fisiología
13.
Chemistry ; 24(52): 13758-13761, 2018 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-30069965

RESUMEN

There is an urgent need to identify new, non-traditional antimicrobials. The discovery of new polymeric antimicrobials is limited by current low-throughput synthetic tools, which means that limited chemical space has been explored. Herein, we employ photochemical "in-air" reversible addition-fragmentation chain-transfer (RAFT) polymerization with microwell plates, using liquid-handling robots to assemble large libraries of cationic polymers, without the need for degassing or purification steps, facilitating transfer to screening. Several lead polymers were identified including a co-polymer with propylene glycol side chains with significantly enhanced antimicrobial activity and increased therapeutic window. Mechanistic studies showed that this polymer was bacteriostatic, and surprisingly did not lyse the cell membranes, implying an alternative mode of action. This versatile method using simple robotics will help to develop new biomaterials with emergent properties.


Asunto(s)
Antibacterianos/síntesis química , Polímeros/síntesis química , Cationes , Evaluación Preclínica de Medicamentos , Escherichia coli/efectos de los fármacos , Humanos , Luz , Metacrilatos/química , Mycobacterium/efectos de los fármacos , Procesos Fotoquímicos , Polimerizacion , Bibliotecas de Moléculas Pequeñas/síntesis química
14.
Biomacromolecules ; 19(1): 256-264, 2018 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-29195272

RESUMEN

Because of the emergence of antimicrobial resistance to traditional small-molecule drugs, cationic antimicrobial polymers are appealing targets. Mycobacterium tuberculosis is a particular problem, with multi- and total drug resistance spreading and more than a billion latent infections globally. This study reports nanoparticles bearing variable densities of poly(dimethylaminoethyl methacrylate) and the unexpected and distinct mechanisms of action this multivalent presentation imparts against Escherichia coli versus Mycobacterium smegmatis (model of M. tuberculosis), leading to killing or growth inhibition, respectively. A convergent "grafting to" synthetic strategy was used to assemble a 50-member nanoparticle library, and using a high-throughput screen identified that only the smallest (2 nm) particles were stable in both saline and complex cell media. Compared with the linear polymers, the nanoparticles displayed two- and eight-fold enhancements in antimicrobial activity against M. smegmatis and E. coli, respectively. Mechanistic studies demonstrated that the antimicrobial particles were bactericidal against E. coli due to rapid disruption of the cell membranes. Conversely, against M. smegmatis the particles did not lyse the cell membrane but rather had a bacteriostatic effect. These results demonstrate that to develop new polymeric antituberculars the widely assumed, broad spectrum, membrane-disrupting mechanism of polycations must be re-evaluated. It is clear that synthetic nanomaterials can engage in more complex interactions with mycobacteria, which we hypothesize is due to the unique cell envelope at the surface of these bacteria.


Asunto(s)
Antibacterianos/farmacología , Antituberculosos/farmacología , Escherichia coli/efectos de los fármacos , Mycobacterium smegmatis/efectos de los fármacos , Mycobacterium tuberculosis/efectos de los fármacos , Nanopartículas , Polímeros/farmacología , Antibacterianos/química , Antituberculosos/química , Pruebas de Sensibilidad Microbiana , Nanopartículas/química
15.
J Clin Nurs ; 27(15-16): 3081-3090, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29700874

RESUMEN

AIMS AND OBJECTIVES: To examine how the concept of compassion is socially constructed within UK discourse, in response to recommendations that aspiring nurses gain care experience prior to entering nurse education. BACKGROUND: Following a report of significant failings in care, the UK government proposed prior care experience for aspiring nurses as a strategy to enhance compassion amongst the profession. Media reporting of this generated substantial online discussion, which formed the data for this research. There is a need to define how compassion is constructed through language as a limited understanding exists, of what compassion means in health care. This is important, for any meaningful evaluation of quality, compassionate practices. DESIGN: A corpus-informed discourse analysis. METHODS: A 62,626-word corpus of data was analysed using Laurence Anthony software "AntCon", a free corpus analysis toolkit. Frequent words were retrieved and used as a focal point for further analysis. Concordance lines were computed and analysed in the context of which frequent word-types occurred. Patterns of language were revealed and interpreted through researcher immersion. RESULTS: Findings identified that compassion was frequently described in various ways as a natural characteristic attribute. A pattern of language also referred to compassion as something that was not able to be taught, but could be developed through the repetition of behaviours observed in practice learning. In the context of compassion, the word-type "nurse" was used positively. CONCLUSION: This study adds to important debates highlighting how compassion is constructed and defined in the context of nursing. Compassion is constructed as both an individual, personal trait and a professional behaviour to be learnt. Educational design could include effective interpersonal skills training, which may help enhance and develop compassion from within the nursing profession. Likewise, ways of thinking, behaving and communicating should also be addressed by established practitioners to maintain compassionate interactions between professionals as well as nurse-patient relationships. Future research should focus on how compassionate practice is defined by both health professionals and patients. RELEVANCE TO CLINICAL PRACTICE: To maintain nursing as an attractive profession to join, it is important that nurses are viewed as compassionate. This holds implications for professional morale, associated with the continued retention and recruitment of the future workforce. Existing ideologies within the practice placement, the prior care experience environment, as well as the educational and organisational design, are crucial factors to consider, in terms of their influences on the expression of compassion in practice.


Asunto(s)
Formación de Concepto , Empatía , Rol de la Enfermera , Relaciones Enfermero-Paciente , Competencia Clínica , Humanos , Aprendizaje , Reino Unido
16.
Biomacromolecules ; 18(5): 1592-1599, 2017 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-28365981

RESUMEN

Antimicrobial resistance is a global healthcare problem with a dwindling arsenal of usable drugs. Tuberculosis, caused by Mycobacterium tuberculosis, requires long-term combination therapy and multi- and totally drug resistant strains have emerged. This study reports the antibacterial activity of cationic polymers against mycobacteria, which are distinguished from other Gram-positive bacteria by their unique cell wall comprising a covalently linked mycolic acid-arabinogalactan-peptidoglycan complex (mAGP), interspersed with additional complex lipids which helps them persist in their host. The present study finds that poly(dimethylaminoethyl methacrylate) has particularly potent antimycobacterial activity and high selectivity over two Gram-negative strains. Removal of the backbone methyl group (poly(dimethylaminoethyl acrylate)) decreased antimycobacterial activity, and poly(aminoethyl methacrylate) also had no activity against mycobacteria. Hemolysis assays revealed poly(dimethylaminoethyl methacrylate) did not disrupt red blood cell membranes. Interestingly, poly(dimethylaminoethyl methacrylate) was not found to permeabilize mycobacterial membranes, as judged by dye exclusion assays, suggesting the mode of action is not simple membrane disruption, supported by electron microscopy analysis. These results demonstrate that synthetic polycations, with the correctly tuned structure are useful tools against mycobacterial infections, for which new drugs are urgently required.


Asunto(s)
Antituberculosos/química , Metacrilatos/química , Mycobacterium/efectos de los fármacos , Nylons/química , Poliaminas/química , Antituberculosos/efectos adversos , Antituberculosos/farmacología , Membrana Celular/efectos de los fármacos , Eritrocitos/efectos de los fármacos , Hemólisis , Metacrilatos/farmacología , Nylons/farmacología , Poliaminas/efectos adversos , Poliaminas/farmacología , Polielectrolitos
17.
Analyst ; 141(14): 4305-12, 2016 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-27181289

RESUMEN

The development of new analytical tools as point-of-care biosensors is crucial to combat the spread of infectious diseases, especially in the context of drug-resistant organisms, or to detect biological warfare agents. Glycan/lectin interactions drive a wide range of recognition and signal transduction processes within nature and are often the first site of adhesion/recognition during infection making them appealing targets for biosensors. Glycosylated gold nanoparticles have been developed that change colour from red to blue upon interaction with carbohydrate-binding proteins and may find use as biosensors, but are limited by the inherent promiscuity of some of these interactions. Here we mimic the natural heterogeneity of cell-surface glycans by displaying mixed monolayers of glycans on the surface of gold nanoparticles. These are then used in a multiplexed, label-free bioassay to create 'barcodes' which describe the lectin based on its binding profile. The increased information content encoded by using complex mixtures of a few sugars, rather than increased numbers of different sugars makes this approach both scalable and accessible. These nanoparticles show increased lectin identification power at a range of lectin concentrations, relative to single-channel sensors. It was also found that some information about the concentration of the lectins can be extracted, all from just a simple colour change, taking this technology closer to being a realistic biosensor.


Asunto(s)
Técnicas Biosensibles , Oro , Lectinas/química , Nanopartículas del Metal , Polisacáridos/química
18.
J Clin Apher ; 31(5): 434-42, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26415895

RESUMEN

Plerixafor is an effective haematopoietic stem cell mobilising agent in candidates for autologous transplantation, including patients with myeloma and lymphoma. Here we compare 98 plerixafor recipients in the PHANTASTIC trial with 151 historic controls mobilised by conventional chemotherapy (each with granulocyte colony-stimulating factor, G-CSF). Seventy (71.4%) plerixafor-mobilised patients achieved the composite primary endpoint of ≥4 × 10(6) CD34+ cells kg(-1) in ≤2 aphereses and no clinically significant neutropenia, compared to 48 (31.8%) historic controls (P < 0.001), and this significant advantage was maintained in scenario analyses testing components of this composite endpoint. A patient-level cost analysis was undertaken for 249 patients, which included the cost of remobilising patients where initial mobilisation had failed. Combined mean treatment cost for plerixafor mobilised patients was £12,679 compared with £11,694 for historical controls. However, plerixafor produces an average saving of £3,828 per lymphoma patient but average cost increase by £5,245 per myeloma patient. The present data demonstrate cost-effectiveness for plerixafor as a first line mobilisation agent, certainly for lymphoma patients, where substantial resource savings and achievement of the primary endpoint are likely. J. Clin. Apheresis 31:434-442, 2016. © 2015 Wiley Periodicals, Inc.


Asunto(s)
Movilización de Célula Madre Hematopoyética/métodos , Compuestos Heterocíclicos/uso terapéutico , Bencilaminas , Análisis Costo-Beneficio , Costos y Análisis de Costo , Ciclamas , Factor Estimulante de Colonias de Granulocitos/economía , Factor Estimulante de Colonias de Granulocitos/uso terapéutico , Movilización de Célula Madre Hematopoyética/economía , Compuestos Heterocíclicos/economía , Estudio Históricamente Controlado , Humanos , Linfoma/economía , Linfoma/terapia , Mieloma Múltiple/economía , Mieloma Múltiple/terapia
19.
J Exp Bot ; 66(17): 5375-84, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26019259

RESUMEN

The root meristem of Arabidopsis thaliana harbours a pool of stem cells, which divide to give rise to the differentiated cells of the various root tissues. Regulatory networks of inter-cellular signalling molecules control the homeostasis of stem cell number and position so that both stem and differentiated cells are consistently available. This work focuses on the transcription factor WUSCHEL-RELATED HOMEOBOX 5 (WOX5), the signalling peptide CLAVATA3/EMBRYO-SURROUNDING REGION 40 (CLE40) and the feedback loops involving them, which maintain the columella stem cells (CSCs). WOX5 signals from the quiescent centre (QC) to promote stem cell fate, while CLE40 is secreted from the differentiated columella cells (CCs) to promote differentiation. Our analyses of mathematical models of this network show that, when cell fate is controlled primarily by antagonistic factors, homeostasis requires a spatial component and inter-cellular signalling. We have also found that WOX5 contributes to, but is not absolutely necessary for, CSC maintenance. Furthermore, our modelling led us to postulate an additional signalling molecule that promotes CSC maintenance. We propose that this WOX5-independent signal originates in the QC, is targeted by CLE40 signalling and is capable of maintaining CSCs.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/fisiología , Regulación de la Expresión Génica de las Plantas , Proteínas de Homeodominio/genética , Modelos Genéticos , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Diferenciación Celular , Proteínas de Homeodominio/metabolismo , Homeostasis , Meristema/fisiología , Raíces de Plantas/fisiología , Células Madre/citología , Células Madre/fisiología
20.
Int J Neuropsychopharmacol ; 18(9)2015 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-25857821

RESUMEN

BACKGROUND: Acute stress triggers transient alterations in the synaptic release and metabolism of brain monoamine neurotransmitters. These rapid changes are essential to activate neuroplastic processes aimed at the appraisal of the stressor and enactment of commensurate defensive behaviors. Threat evaluation has been recently associated with the dendritic morphology of pyramidal cells in the orbitofrontal cortex (OFC) and basolateral amygdala (BLA); thus, we examined the rapid effects of restraint stress on anxiety-like behavior and dendritic morphology in the BLA and OFC of mice. Furthermore, we tested whether these processes may be affected by deficiency of monoamine oxidase A (MAO-A), the primary enzyme catalyzing monoamine metabolism. METHODS: Following a short-term (1-4h) restraint schedule, MAO-A knockout (KO) and wild-type (WT) mice were sacrificed, and histological analyses of dendrites in pyramidal neurons of the BLA and OFC of the animals were performed. Anxiety-like behaviors were examined in a separate cohort of animals subjected to the same experimental conditions. RESULTS: In WT mice, short-term restraint stress significantly enhanced anxiety-like responses, as well as a time-dependent proliferation of apical (but not basilar) dendrites of the OFC neurons; conversely, a retraction in BLA dendrites was observed. None of these behavioral and morphological changes were observed in MAO-A KO mice. CONCLUSIONS: These findings suggest that acute stress induces anxiety-like responses by affecting rapid dendritic remodeling in the pyramidal cells of OFC and BLA; furthermore, our data show that MAO-A and monoamine metabolism are required for these phenomena.


Asunto(s)
Ansiedad/enzimología , Complejo Nuclear Basolateral/patología , Dendritas/patología , Monoaminooxidasa/metabolismo , Corteza Prefrontal/patología , Células Piramidales/patología , Estrés Psicológico/enzimología , Animales , Ansiedad/etiología , Modelos Animales de Enfermedad , Masculino , Ratones , Ratones de la Cepa 129 , Monoaminooxidasa/deficiencia , Estrés Psicológico/complicaciones
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA