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1.
J Virol ; 97(9): e0055523, 2023 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-37668370

RESUMEN

In vitro investigations of host-virus interactions are reliant on suitable cell and tissue culture models. Results are only as good as the model they are generated in. However, choosing cell models for in vitro work often depends on availability and previous use alone. Despite the vast increase in coronavirus research over the past few years, scientists are still heavily reliant on: non-human, highly heterogeneous or not fully differentiated, or naturally unsusceptible cells requiring overexpression of receptors and other accessory factors. Complex primary or stem cell models are highly representative of human tissues but are expensive and time-consuming to develop and maintain with limited suitability for high-throughput experiments.Using tissue-specific expression patterns, we identified human kidney cells as an ideal target for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and broader coronavirus infection. We show the use of the well-characterized human kidney cell line Caki-1 for infection with three human coronaviruses (hCoVs): Betacoronaviruses SARS-CoV-2 and Middle Eastern respiratory syndrome coronavirus and Alphacoronavirus hCoV 229E. Caki-1 cells show equal or superior susceptibility to all three coronaviruses when compared to other commonly used cell lines for the cultivation of the respective virus. Antibody staining against SARS-CoV-2 N protein shows comparable replication rates. A panel of 26 custom antibodies shows the location of SARS-CoV-2 proteins during replication using immunocytochemistry. In addition, Caki-1 cells were found to be susceptible to two other human respiratory viruses, influenza A virus and respiratory syncytial virus, making them an ideal model for cross-comparison for a broad range of respiratory viruses. IMPORTANCE Cell lines remain the backbone of virus research, but results are only as good as their originating model. Despite increased research into human coronaviruses following the COVID-19 pandemic, researchers continue to rely on suboptimal cell line models of: non-human origin, incomplete differentiation, or lacking active interferon responses. We identified the human kidney Caki-1 cell line as a potential target for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This cell line could be shown to be infectable with a wide range of coronaviruses including common cold virus hCoV-229E, epidemic virus MERS-CoV, and SARS-CoV-2 as well as other important respiratory viruses influenza A virus and respiratory syncytial virus. We could show the localization of 26 SARS-CoV-2 proteins in Caki-1 cells during natural replication and the cells are competent of forming a cellular immune response. Together, this makes Caki-1 cells a unique tool for cross-virus comparison in one cell line.


Asunto(s)
Línea Celular , Infecciones por Coronaviridae , Coronaviridae , Humanos , Coronaviridae/fisiología , Riñón/citología , Pandemias , Infecciones por Coronaviridae/patología , Infecciones por Coronaviridae/virología
2.
Chemistry ; 30(40): e202401465, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-38743746

RESUMEN

The regiodivergent synthesis of 4- and 5-sulfenyl oxazoles from 1,4,2-dioxazoles and alkynyl thioethers has been achieved. Gold-catalysed conditions are used to favour the formation of 5-sulfenyl oxazoles via ß-selective attack of the nitrenoid relative to the sulfenyl group. In contrast, 4-sulfenyl oxazoles are formed by α-selective reaction under Brønsted acid conditions from the same substrates. The nature of stabilising gold-sulfur interactions have been investigated by natural bond orbital analysis, showing that the S→Au interactions are significantly stronger in the intermediate that favours the 5-sulfenyl oxazoles. A kinetic survey identifies catalyst inhibition processes. This study into the regiodivergent methods includes the development of telescoped annulation-oxidation protocols for regioselective access to oxazole sulfoxides and sulfones.

3.
PLoS Biol ; 19(2): e3001091, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33630831

RESUMEN

The recent emergence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the underlying cause of Coronavirus Disease 2019 (COVID-19), has led to a worldwide pandemic causing substantial morbidity, mortality, and economic devastation. In response, many laboratories have redirected attention to SARS-CoV-2, meaning there is an urgent need for tools that can be used in laboratories unaccustomed to working with coronaviruses. Here we report a range of tools for SARS-CoV-2 research. First, we describe a facile single plasmid SARS-CoV-2 reverse genetics system that is simple to genetically manipulate and can be used to rescue infectious virus through transient transfection (without in vitro transcription or additional expression plasmids). The rescue system is accompanied by our panel of SARS-CoV-2 antibodies (against nearly every viral protein), SARS-CoV-2 clinical isolates, and SARS-CoV-2 permissive cell lines, which are all openly available to the scientific community. Using these tools, we demonstrate here that the controversial ORF10 protein is expressed in infected cells. Furthermore, we show that the promising repurposed antiviral activity of apilimod is dependent on TMPRSS2 expression. Altogether, our SARS-CoV-2 toolkit, which can be directly accessed via our website at https://mrcppu-covid.bio/, constitutes a resource with considerable potential to advance COVID-19 vaccine design, drug testing, and discovery science.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19/diagnóstico , COVID-19/virología , Genética Inversa , SARS-CoV-2/genética , Células A549 , Enzima Convertidora de Angiotensina 2/metabolismo , Animales , Chlorocebus aethiops , Codón , Humanos , Hidrazonas/farmacología , Ratones , Morfolinas/farmacología , Sistemas de Lectura Abierta , Plásmidos/genética , Pirimidinas/farmacología , Serina Endopeptidasas/metabolismo , Células Vero , Proteínas Virales/metabolismo
4.
Beilstein J Org Chem ; 20: 621-627, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38533470

RESUMEN

A polysubstituted 3-aminoimidazo[5,1-b]oxazol-6-ium framework has been accessed from a new nitrenoid reagent by a two-step ynamide annulation and imidazolium ring-formation sequence. Metalation with Au(I), Cu(I) and Ir(I) at the C2 position provides an L-shaped NHC ligand scaffold that has been validated in gold-catalysed alkyne hydration and arylative cyclisation reactions.

5.
Bioorg Med Chem Lett ; 94: 129449, 2023 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-37591317

RESUMEN

The discovery of disease-modifying therapies for Parkinson's Disease (PD) represents a critical need in neurodegenerative medicine. Genetic mutations in leucine-rich repeat kinase 2 (LRRK2) are risk factors for the development of PD, and some of these mutations have been linked to increased LRRK2 kinase activity and neuronal toxicity in cellular and animal models. Furthermore, LRRK2 function as a scaffolding protein in several pathways has been implicated as a plausible mechanism underlying neurodegeneration caused by LRRK2 mutations. Given that both the kinase activity and scaffolding function of LRRK2 have been linked to neurodegeneration, we developed proteolysis-targeting chimeras (PROTACs) targeting LRRK2. The degrader molecule JH-XII-03-02 (6) displayed high potency and remarkable selectivity for LRKK2 when assessed in a of 468 panel kinases and serves the dual purpose of eliminating both the kinase activity as well as the scaffolding function of LRRK2.


Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina , Enfermedad de Parkinson , Animales , Modelos Animales , Mutación , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/genética , Fosforilación , Quimera Dirigida a la Proteólisis , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/antagonistas & inhibidores
6.
Bioessays ; 43(7): e2000305, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33984158

RESUMEN

It has long been recognized that cancer onset and progression represent a type of reversion to an ancestral quasi-unicellular phenotype. This general concept has been refined into the atavistic model of cancer that attempts to provide a quantitative analysis and testable predictions based on genomic data. Over the past decade, support for the multicellular-to-unicellular reversion predicted by the atavism model has come from phylostratigraphy. Here, we propose that cancer onset and progression involve more than a one-off multicellular-to-unicellular reversion, and are better described as a series of reversionary transitions. We make new predictions based on the chronology of the unicellular-eukaryote-to-multicellular-eukaryote transition. We also make new predictions based on three other evolutionary transitions that occurred in our lineage: eukaryogenesis, oxidative phosphorylation and the transition to adaptive immunity. We propose several modifications to current phylostratigraphy to improve age resolution to test these predictions. Also see the video abstract here: https://youtu.be/3unEu5JYJrQ.


Asunto(s)
Evolución Biológica , Neoplasias , Eucariontes , Células Eucariotas , Humanos , Neoplasias/genética , Fenotipo
7.
J Biol Chem ; 296: 100364, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33539918

RESUMEN

The K+/Cl- cotransporter KCC2 (SLC12A5) allows mature neurons in the CNS to maintain low intracellular Cl- levels that are critical in mediating fast hyperpolarizing synaptic inhibition via type A γ-aminobutyric acid receptors (GABAARs). In accordance with this, compromised KCC2 activity results in seizures, but whether such deficits directly contribute to the subsequent changes in neuronal structure and viability that lead to epileptogenesis remains to be assessed. Canonical hyperpolarizing GABAAR currents develop postnatally, which reflect a progressive increase in KCC2 expression levels and activity. To investigate the role that KCC2 plays in regulating neuronal viability and architecture, we have conditionally ablated KCC2 expression in developing and mature neurons. Decreasing KCC2 expression in mature neurons resulted in the rapid activation of the extrinsic apoptotic pathway. Intriguingly, direct pharmacological inhibition of KCC2 in mature neurons was sufficient to rapidly induce apoptosis, an effect that was not abrogated via blockade of neuronal depolarization using tetrodotoxin (TTX). In contrast, ablating KCC2 expression in immature neurons had no discernable effects on their subsequent development, arborization, or dendritic structure. However, removing KCC2 in immature neurons was sufficient to ablate the subsequent postnatal development of hyperpolarizing GABAAR currents. Collectively, our results demonstrate that KCC2 plays a critical role in neuronal survival by limiting apoptosis, and mature neurons are highly sensitive to the loss of KCC2 function. In contrast, KCC2 appears to play a minimal role in mediating neuronal development or architecture.


Asunto(s)
Neuronas/metabolismo , Simportadores/metabolismo , Animales , Apoptosis , Cloruros/metabolismo , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurogénesis/efectos de los fármacos , Neuronas/fisiología , Potasio/metabolismo , Cultivo Primario de Células , Receptores de GABA/metabolismo , Convulsiones , Simportadores/fisiología , Ácido gamma-Aminobutírico/metabolismo , Cotransportadores de K Cl
8.
EMBO J ; 37(12)2018 06 15.
Artículo en Inglés | MEDLINE | ID: mdl-29789389

RESUMEN

Mutations in the leucine-rich repeat kinase 2 (LRRK2) are associated with Parkinson's disease, chronic inflammation and mycobacterial infections. Although there is evidence supporting the idea that LRRK2 has an immune function, the cellular function of this kinase is still largely unknown. By using genetic, pharmacological and proteomics approaches, we show that LRRK2 kinase activity negatively regulates phagosome maturation via the recruitment of the Class III phosphatidylinositol-3 kinase complex and Rubicon to the phagosome in macrophages. Moreover, inhibition of LRRK2 kinase activity in mouse and human macrophages enhanced Mycobacterium tuberculosis phagosome maturation and mycobacterial control independently of autophagy. In vivo, LRRK2 deficiency in mice resulted in a significant decrease in M. tuberculosis burdens early during the infection. Collectively, our findings provide a molecular mechanism explaining genetic evidence linking LRRK2 to mycobacterial diseases and establish an LRRK2-dependent cellular pathway that controls M. tuberculosis replication by regulating phagosome maturation.


Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/inmunología , Macrófagos/inmunología , Mycobacterium tuberculosis/inmunología , Fagosomas/inmunología , Tuberculosis/inmunología , Animales , Proteínas Relacionadas con la Autofagia , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/inmunología , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Macrófagos/microbiología , Ratones , Ratones Noqueados , Fagosomas/genética , Fagosomas/microbiología , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/inmunología , Tuberculosis/genética
9.
NMR Biomed ; 35(2): e4630, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34647377

RESUMEN

1 H-magnetic resonance spectroscopy (MRS) provides noninvasive metabolite profiles with the potential to aid the diagnosis of brain tumours. Prospective studies of diagnostic accuracy and comparisons with conventional MRI are lacking. The aim of the current study was to evaluate, prospectively, the diagnostic accuracy of a previously established classifier for diagnosing the three major childhood cerebellar tumours, and to determine added value compared with standard reporting of conventional imaging. Single-voxel MRS (1.5 T, PRESS, TE 30 ms, TR 1500 ms, spectral resolution 1 Hz/point) was acquired prospectively on 39 consecutive cerebellar tumours with histopathological diagnoses of pilocytic astrocytoma, ependymoma or medulloblastoma. Spectra were analysed with LCModel and predefined quality control criteria were applied, leaving 33 cases in the analysis. The MRS diagnostic classifier was applied to this dataset. A retrospective analysis was subsequently undertaken by three radiologists, blind to histopathological diagnosis, to determine the change in diagnostic certainty when sequentially viewing conventional imaging, MRS and a decision support tool, based on the classifier. The overall classifier accuracy, evaluated prospectively, was 91%. Incorrectly classified cases, two anaplastic ependymomas, and a rare histological variant of medulloblastoma, were not well represented in the original training set. On retrospective review of conventional MRI, MRS and the classifier result, all radiologists showed a significant increase (Wilcoxon signed rank test, p < 0.001) in their certainty of the correct diagnosis, between viewing the conventional imaging and MRS with the decision support system. It was concluded that MRS can aid the noninvasive diagnosis of posterior fossa tumours in children, and that a decision support classifier helps in MRS interpretation.


Asunto(s)
Neoplasias Cerebelosas/diagnóstico , Espectroscopía de Resonancia Magnética/métodos , Adolescente , Neoplasias Cerebelosas/patología , Niño , Preescolar , Sistemas de Apoyo a Decisiones Clínicas , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Estudios Prospectivos
10.
J Cardiothorac Vasc Anesth ; 36(3): 684-689, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34479781

RESUMEN

OBJECTIVES: Recombinant activated factor VIIa (rVIIa) is used off-label for refractory bleeding after cardiac surgery. This study reviewed the indications, usage rates, and complications of rVIIa. DESIGN: A retrospective case-control observational study. SETTING: A single quaternary pediatric hospital. PARTICIPANTS: All children undergoing cardiac surgery with cardiopulmonary bypass over a three-year period. INTERVENTIONS: Administration of rVIIa as rescue therapy for refractory bleeding after weaning from cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Onethousand, five hundred fifteen cardiopulmonary bypass procedures were reviewed. Patients receiving rVIIa were each matched to two control patients by age, procedure type, and bypass time. Data collected included weight, crossclamp time, anticoagulant and antifibrinolytic dose, return to the operating room for bleeding, thrombotic events, and extracorporeal membrane oxygenation (ECMO) circuit interventions. Forty-two patients received rVIIa (2.8%). Major systemic thrombotic complications were observed in 19% (controls 12.5%) of patients; 80% of recombinant factor VIIa patients requiring postoperative ECMO had interventions for circuit thrombosis (controls 31.25%); 4.76% of rVIIa recipients required reexploration for intractable bleeding (controls 1.39%). CONCLUSIONS: This study added to understanding regarding the use of recombinant factor VIIa in pediatric cardiac surgery and reported increased thrombotic complications, especially for children who progress to ECMO. Prospective studies to better understand the pathophysiology of coagulopathy and hemorrhage in pediatric cardiac surgery and the role of hemostatic agents, such as rVIIa, are required.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Factor VIIa , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/métodos , Niño , Factor VIIa/efectos adversos , Humanos , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Estudios Retrospectivos
11.
Br J Neurosurg ; 36(6): 720-727, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35938178

RESUMEN

PURPOSE: This study assesses postoperative quality-of-life outcomes via the Glasgow Benefit Inventory (GBI) in patients undergoing transnasal endoscopic pituitary surgery for pituitary adenoma. METHODS: This was a retrospective cohort study in a UK tertiary referral centre. 145 patients who had undergone transnasal endoscopic pituitary surgery for pituitary adenoma over a 6-year period at one institution completed the GBI with at least 3 months' follow up. Patients with prior radiotherapy were excluded. The GBI is a patient-reported outcome measure that assesses post-intervention outcomes in three domains: 'general' functioning, 'social support' and 'physical' functioning. Pre- and post-operative visual loss scores were additionally assessed via a 1-5 Likert scale. GBI scores were assessed alongside these visual loss scores, clinical and surgical parameters and demographics. RESULTS: Mean age was 59.5 years (range 20-87 years) and mean follow up was 36 months. A total of 46 of 145 (31.7%) patients had secreting tumours. The most common primary symptom was visual loss. Mean total score for all patients was positive (+8.4); with 'general' domain score the most positive (+10.5). All patient groups had overall positive, 'general' and 'social support' domain scores. Patients with Cushing's disease reported significantly higher mean total scores (+29.6) than all other groups. Acromegaly (+7.9) and non-functioning adenoma (NFA) groups (+5.2) reported lower mean total scores. 'Physical' domain mean scores were negative for acromegaly and NFA groups. There was statistical significance between a pre- to post-operative improvement in visual score and mean total GBI score (p = 0.02) and mean 'general' domain GBI score (p = 0.02). CONCLUSIONS: These findings can aid preoperative counselling of patients undergoing this surgery. Those with NFA and no anticipated improvement to visual loss symptoms may be advised of possible worsened physical outcomes and of the option to delay the surgery until symptoms are present.


Asunto(s)
Acromegalia , Neoplasias Hipofisarias , Humanos , Lactante , Preescolar , Niño , Neoplasias Hipofisarias/cirugía , Calidad de Vida , Estudios Retrospectivos , Endoscopía , Resultado del Tratamiento
12.
Chem Rec ; 21(12): 3964-3977, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34708496

RESUMEN

The combination of a nucleophilic nitrene equivalent, a triple bond and a π-acid catalyst has underpinned numerous efficient transformations for the preparation of azacycles. This personal account details our efforts in developing an annulation strategy. Adding a nucleophilic nitrenoid to an activated alkyne can generate carbenoid character that is then quenched by a cyclisation onto the nitrenoid substituent. The use and development of N-acyl and N-heterocyclic pyridinium-N-aminides as 1,3-N,O and 1,3-N,N-dipole equivalents is discussed in the context of oxazole and heterocycle-fused imidazole formation, respectively. The resulting processes are highly efficient, practically straightforward, and tolerate considerable structural and functional group variation. Our use of heteroatom-substituted alkynes as enabling tools for reaction discovery is discussed. The reactivity accessed from the strong donor-like properties of ynamides is complemented by that obtained from alkynyl thioethers, which are emerging as interesting substrates for π-acid catalysis.

13.
Pharmacol Res ; 169: 105653, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33962015

RESUMEN

The signalling characteristics of the Zinc-Activated Channel (ZAC), a member of the Cys-loop receptor (CLR) superfamily, are presently poorly elucidated. The ZACN polymorphism c.454G>A encoding for the Thr128Ala variation in ZAC is found in extremely high allele frequencies across ethnicities. In this, the first study of ZAC in Xenopus oocytes by TEVC electrophysiology, ZACThr128 and ZACAla128 exhibited largely comparable pharmacological and signalling characteristics, but interestingly the Zn2+- and H+-evoked current amplitudes in ZACAla128-oocytes were dramatically smaller than those in ZACThr128-oocytes. While the variation thus appeared to impact cell surface expression and/or channel properties of ZAC, the similar expression properties exhibited by ZACThr128 and ZACAla128 in transfected mammalian cells indicated that their distinct functionalities could arise from the latter. In co-expression experiments, wild-type and variant ZAC subunits assembled efficiently into "heteromeric" complexes in HEK293 cells, while the concomitant presence of ZACAla128 in ZACThr128:ZACAla128-oocytes did not exert a dominant negative effect on agonist-evoked current amplitudes compared to those in ZACThr128-oocytes. Finally, the structural determinants of the functional importance of the 1-hydroxyethyl side-chain of Thr128 appeared to be subtle, as agonist-evoked current amplitudes in ZACSer128-, ZACVal128- and ZACIle128-oocytes also were substantially lower than those in ZACThr128-oocytes. In conclusion, the functional properties exhibited by ZAC in this work substantiate the notion of it being an atypical CLR. While the impact of the Thr128Ala variation on ZAC functionality in oocytes is striking, it remains to be investigated whether and to which extent this translates into an in vivo setting and thus could constitute a source of inter-individual variation in ZAC physiology.


Asunto(s)
Canales Iónicos/metabolismo , Zinc/metabolismo , Animales , Ensayo de Inmunoadsorción Enzimática , Inmunoprecipitación , Canales Iónicos/genética , Canales Iónicos/fisiología , Oocitos/metabolismo , Polimorfismo de Nucleótido Simple/genética , Xenopus laevis
14.
J Microsc ; 284(3): 189-202, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34313326

RESUMEN

Atomic force microscopy integrated with infrared spectroscopy (AFM-IR) has been used to topographically and chemically examine the medulla of human hair fibres with nanometre scale lateral resolution. The mapping of cross-sections of the medulla showed two distinct structural components which were subsequently characterised spectroscopically. One of these components was shown to be closely similar to cortical cell species, consistent with the fibrillar structures found in previous electron microscope (EM) investigations. The other component showed large chemical differences from cortical cells and was assigned to globular vacuole species, also confirming EM observations. Further characterisation of the two components was achieved through spectral deconvolution of the protein Amide-I and -II bands. This showed that the vacuoles have a greater proportion of the most thermodynamically stable conformation, namely the antiparallel ß-sheet structures. This chimes with the observed lower cysteine concentration, indicating a lower proportion of restrictive disulphide cross-link bonding. Furthermore, the large α-helix presence within the vacuoles points to a loss of matrix-like material as well as significant intermolecular stabilisation of the protein structures. By analysing the carbonyl stretching region, it was established that the fibrillar, cortical cell-like components showed considerable stabilisation from H-bonding interactions, similar to the cortex, involving amino acid side chains whereas, in contrast, the vacuoles were found to only be stabilised significantly by structural lipids.


Asunto(s)
Cabello , Lípidos/química , Proteínas , Humanos , Microscopía de Fuerza Atómica , Espectrofotometría Infrarroja
15.
EMBO Rep ; 20(7): e46436, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31267714

RESUMEN

All vertebrates share a segmented body axis. Segments form from the rostral end of the presomitic mesoderm (PSM) with a periodicity that is regulated by the segmentation clock. The segmentation clock is a molecular oscillator that exhibits dynamic clock gene expression across the PSM with a periodicity that matches somite formation. Notch signalling is crucial to this process. Altering Notch intracellular domain (NICD) stability affects both the clock period and somite size. However, the mechanism by which NICD stability is regulated in this context is unclear. We identified a highly conserved site crucial for NICD recognition by the SCF E3 ligase, which targets NICD for degradation. We demonstrate both CDK1 and CDK2 can phosphorylate NICD in the domain where this crucial residue lies and that NICD levels vary in a cell cycle-dependent manner. Inhibiting CDK1 or CDK2 activity increases NICD levels both in vitro and in vivo, leading to a delay of clock gene oscillations and an increase in somite size.


Asunto(s)
Relojes Biológicos , Proteína Quinasa CDC2/metabolismo , Quinasa 2 Dependiente de la Ciclina/metabolismo , Proteolisis , Receptores Notch/metabolismo , Animales , Ciclo Celular , Células Cultivadas , Secuencia Conservada , Células Madre Embrionarias/metabolismo , Células HEK293 , Humanos , Ratones , Fosforilación , Dominios Proteicos , Estabilidad Proteica , Receptores Notch/química
16.
Eur J Clin Pharmacol ; 77(4): 625-635, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33119787

RESUMEN

PURPOSE: The purpose of this international study was to investigate prescribing practices of dexmedetomidine by paediatric anaesthesiologists. METHODS: We performed an online survey on the prescription rate of dexmedetomidine, route of administration and dosage, adverse drug reactions, education on the drug and overall experience. Members of specialist paediatric anaesthesia societies of Europe (ESPA), New Zealand and Australia (SPANZA), Great Britain and Ireland (APAGBI) and the USA (SPA) were consulted. Responses were collected in July and August 2019. RESULTS: Data from 791 responders (17% of 5171 invitees) were included in the analyses. Dexmedetomidine was prescribed by 70% of the respondents (ESPA 53%; SPANZA 69%; APAGBI 34% and SPA 96%), mostly for procedural sedation (68%), premedication (46%) and/or ICU sedation (46%). Seventy-three percent had access to local or national protocols, although lack of education was the main reason cited by 26% of the respondents not to prescribe dexmedetomidine. The main difference in dexmedetomidine use concerned the age of patients (SPA primarily < 1 year, others primarily > 1 year). The dosage varied widely ranging from 0.2-5 µg kg-1 for nasal premedication, 0.2-8 µg kg-1 for nasal procedural sedation and 0-4 µg kg-1 intravenously as adjuvant for anaesthesia. Only ESPA members (61%) had noted an adverse drug reaction, namely bradycardia. CONCLUSION: The majority of anaesthesiologists use dexmedetomidine in paediatrics for premedication, procedural sedation, ICU sedation and anaesthesia, despite the off-label use and sparse evidence. The large intercontinental differences in prescribing dexmedetomidine call for consensus and worldwide education on the optimal use in paediatric practice.


Asunto(s)
Dexmedetomidina/administración & dosificación , Hipnóticos y Sedantes/administración & dosificación , Uso Fuera de lo Indicado/estadística & datos numéricos , Anestesiólogos , Anestesiología , Niño , Dexmedetomidina/efectos adversos , Humanos , Hipnóticos y Sedantes/efectos adversos , Pediatría , Encuestas y Cuestionarios
17.
Biophys J ; 119(8): 1474-1480, 2020 10 20.
Artículo en Inglés | MEDLINE | ID: mdl-33035449

RESUMEN

The air sensitivity of many substrates, and specifically biosurfaces, presents an experimental challenge for their analysis by vibrational spectroscopy and, in particular, infrared microscopy on a nanometer scale. The recent development of atomic-force-microscopy-based infrared spectroscopy (AFM-IR), which circumvents the Abbe diffraction limit, allows nanoscale chemical characterization of surfaces. Additionally, this technique has been shown to work for thin films under aqueous environments but is limited to substrates up to 10 nm thick, thus ruling out application to many biological surfaces. To circumvent this restriction, we have utilized hydrogels to cover such surfaces and maintain a more physiologically representative environment for biological substrates. We show that it is feasible to use AFM-IR to chemically characterize this type of substrate buried under a thin hydrogel film. Specifically, this work describes the AFM-IR spectra of red blood cells under polyvinyl alcohol hydrogels.


Asunto(s)
Eritrocitos , Hidrogeles , Espectrofotometría Infrarroja , Metilgalactósidos , Microscopía de Fuerza Atómica
18.
J Biol Chem ; 294(32): 12220-12230, 2019 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-31239352

RESUMEN

Neuroactive steroids (NASs) are synthesized within the brain and exert profound effects on behavior. These effects are primarily believed to arise from the activities of NASs as positive allosteric modulators (PAMs) of the GABA-type A receptor (GABAAR). NASs also activate a family of G protein-coupled receptors known as membrane progesterone receptors (mPRs). Here, using surface-biotinylation assays and electrophysiology techniques, we examined mPRs' role in mediating the effects of NAS on the efficacy of GABAergic inhibition. Selective mPR activation enhanced phosphorylation of Ser-408 and Ser-409 (Ser-408/9) within the GABAAR ß3 subunit, which depended on the activity of cAMP-dependent protein kinase A (PKA) and protein kinase C (PKC). mPR activation did not directly modify GABAAR activity and had no acute effects on phasic or tonic inhibition. Instead, mPR activation induced a sustained elevation in tonic current, which was blocked by PKA and PKC inhibition. Substitution of Ser-408/9 to alanine residues also prevented the effects of mPR activation on tonic current. Furthermore, this substitution abolished the effects of sustained NAS exposure on tonic inhibition. Interestingly, the allosteric effects of NAS on GABAergic inhibition were independent of Ser-408/9 in the ß3 subunit. Additionally, although allosteric effects of NAS on GABAergic inhibition were sensitive to a recently developed "NAS antagonist," the sustained effects of NAS on tonic inhibition were not. We conclude that metabotropic effects of NAS on GABAergic inhibition are mediated by mPR-dependent modulation of GABAAR phosphorylation. We propose that this mechanism may contribute to the varying behavioral effects of NAS.


Asunto(s)
Neuroesteroides/metabolismo , Receptores de GABA-A/metabolismo , Regulación Alostérica/efectos de los fármacos , Animales , Membrana Celular/metabolismo , Potenciales Evocados/efectos de los fármacos , Antagonistas de Receptores de GABA-A/farmacología , Células HEK293 , Hipocampo/metabolismo , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Mutagénesis Sitio-Dirigida , Neuroesteroides/farmacología , Fosforilación/efectos de los fármacos , Proteína Quinasa C/metabolismo , Subunidades de Proteína/química , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Receptores de GABA-A/química , Receptores de GABA-A/genética , Receptores de Progesterona/agonistas , Receptores de Progesterona/genética , Receptores de Progesterona/metabolismo
19.
Eur Spine J ; 29(4): 779-785, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32100105

RESUMEN

PURPOSE: Magnetic-controlled growing rods (MCGRs) are now routinely used in many centres to treat early-onset scoliosis (EOS). MCGR lengthening is done non-invasively by the external remote controller (ERC). Our experience suggests that there may be a discrepancy between the reported rod lengthening on the ERC and the actual rod lengthening. The aim of this study was to investigate this discrepancy. METHODS: This was a prospective series. Eleven patients who were already undergoing treatment for EOS using MCGRs were included in this study. RESULTS: One hundred and ninety-two sets of ultrasound readings were obtained (96 episodes of rod lengthening on dual-rod constructs) and compared to their ERC readings. Only 15/192 (7.8%) readings were accurate; 27 readings (14.9%) were false positive; and 8 readings (4.2%) were an underestimation while 142 readings (74.0%) were an overestimation by the ERC. Average over-reporting by the ERC was 5.31 times of the actual/ultrasound reading. When comparing interval radiographs with lengthening obtained on ultrasound, there was a discrepancy with an average overestimation of 1.35 times with ultrasound in our series. There was a significant difference between ERC and USS (p = 0.01) and ERC and XR (p = 0.001). However, there was no significant difference between USS and XR (p > 0.99). CONCLUSION: The reading on the ERC does not equate to the actual rod lengthening. The authors would recommend that clinicians using the MCGR for the treatment of early-onset scoliosis include pre- and post-extension imaging (radiographs or ultrasound) to confirm extension lengths at each outpatient extension. In centres with ultrasound facilities, we would suggest that patients should have ultrasound to monitor each lengthening after distraction but also 6-month radiographs. These slides can be retrieved under Electronic Supplementary Material.


Asunto(s)
Escoliosis , Niño , Preescolar , Femenino , Humanos , Fenómenos Magnéticos , Masculino , Estudios Prospectivos , Radiografía , Escoliosis/diagnóstico por imagen , Escoliosis/cirugía , Ultrasonografía
20.
Cephalalgia ; 39(5): 641-647, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30409039

RESUMEN

AIM: To explore post traumatic headache characteristics and risk factors in compensation claimants by observational retrospective cohort analysis. CASE RESULTS: Medicolegal reports on 116 consecutive compensation claimants aged 41.9 ± 15.0 years were reviewed 21 ± 14 months after injury. Eighty eight had suffered head and neck injuries, 21 reported only neck injury and seven had "other injuries". Ninety four percent of the head injuries were "mild". The incidence of post traumatic headache following neck injury did not differ from that following head and neck injury, and none of the "other injuries" cases developed post traumatic headache. We anticipated that all head and neck injury claimants would seek compensation for post traumatic headache, but 25% denied developing headache. Post traumatic headache was very strongly correlated with a past history of primary headache ( p < 0.0001) but no other risk factors were identified. Post traumatic headache semiology was consistent with "migraine" or "probable migraine" in 90% of cases. Headache resolved in 30% of claimants between 3 and 24 months after injury but 70% continued to suffer headaches at the time of assessment. Forty one percent of claimants had received no treatment for post traumatic headache in primary care. CONCLUSIONS: Our data suggest that post traumatic headache is essentially "migraine" provoked by head or neck concussion. It is not clear why so many post traumatic headache sufferers receive poor or inadequate treatment for this condition.


Asunto(s)
Conmoción Encefálica/complicaciones , Síndrome Posconmocional/etiología , Cefalea Postraumática/etiología , Adulto , Estudios de Cohortes , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Trastornos Migrañosos/epidemiología , Trastornos Migrañosos/etiología , Síndrome Posconmocional/epidemiología , Cefalea Postraumática/epidemiología , Estudios Retrospectivos , Factores de Riesgo , Reino Unido/epidemiología
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