Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.792
Filtrar
1.
J Phys Chem B ; 2024 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-39500582

RESUMEN

Complementary X-ray absorption fine structure (XAFS) and Raman spectroscopy studies were conducted on various UCl3 concentrations in alkali chloride salt compositions. The samples were 5 mol % UCl3 in LiCl (S1), 5 mol % UCl3 in KCl (S2), 5 mol % UCl3 in LiCl-KCl eutectic (S4), 50 mol % UCl3 in KCl (S5), and 20 mol % UCl3 in KCl (S6) molar concentrations. Samples were heated to 800 °C and allowed to cool to room temperature with measurements performed at selected temperatures; the highest temperatures showed the most stability and will be primarily referenced for conclusions. The processing and interpretation of the Raman and extended X-ray absorption fine structure (EXAFS) peaks revealed several uranium-oxygen bond lengths and symmetries in the samples before, during, and after heating. Based on published thermodynamic data of similar systems, X-ray absorption fine structure spectroscopy, and identification of Raman peaks, a ß variation of α-U3O8, typical at room temperature, is the suspected dominant phase of all samples at high temperatures (800 °C). In the existing literature, this ß structure of U3O8 was synthesized by slow cooling of uranium oxides from 1350 °C. This paper suggests the rapid formation of the compound due to the decomposition of the uranium chlorides or oxychlorides at increasing temperatures and O2 reaction kinetics.

2.
Mov Disord ; 2024 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-39450564

RESUMEN

BACKGROUND: Orthostatic tremor (OT) is a rare movement disorder characterized by a feeling of unsteadiness and a high-frequency tremor in the legs (13-18 Hz) relieved by sitting or walking. OBJECTIVES: The aims were to study the brain electrophysiology captured chronically in a person with medication-refractory OT while standing and walking and in the semi-recumbent position using bilateral ventral intermedius nucleus deep brain stimulation (DBS) (Medtronic Percept PC) and to describe the clinical use of closed-loop DBS. METHODS: A sensing survey was used to capture baseline local field potentials (LFPs) while standing. Livestreamed LFPs were synchronized with data collected from two accelerometers (legs) and gait analysis during OFF stimulation and continuous and closed-loop DBS. RESULTS: Strong oscillatory coupling between thalamic LFP and leg tremor with significant coherence at 14.65 Hz was found during weight-bearing. Single-threshold adaptive DBS (sensing at this frequency) was superior to continuous stimulation in reducing tremor and stimulation-related gait ataxia. CONCLUSIONS: This study provides new insights into both the pathophysiology and management of OT. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

3.
J Chem Phys ; 161(3)2024 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-39017424

RESUMEN

A double harmonic oscillator model is applied to compute the negative ion photoelectron spectra (NIPES) of the 1- and 2-cyanonaphthalene (CNN) radical anions. The computed Franck-Condon factors utilize optimized structures and harmonic vibrational frequencies obtained using density functional theory with the B3LYP 6-311++G (2d,2p) basis set while considering the mode-mixing Duschinsky effects. To test the accuracy of our model, the NIPES of α and ß naphthyl radical anions were computed, and a strong agreement between the slow electron velocity-map ion imaging spectra and the predicted spectra was found. The adiabatic electron affinities (EAs) of the ground singlet states (S0) in 1-CNN and 2-CNN are 0.856 and 0.798 eV, respectively. The origin of the lowest-lying triplet (T1) states in 1-CNN and 2-CNN is found to be 3.226 and 3.266 eV, resulting in singlet-triplet energy splittings (ΔEST) of 2.370 and 2.468 eV, respectively. Both the NIPES for electron detachment to the S0 and T1 states exhibit well-resolved vibrational features, allowing for the assignment of several vibrational fundamental frequencies. Following deprotonation, several isomers are formed, with the most stable deprotonated radical anions in 1-CNN and 2-CNN, corresponding to the removal of the most acidic proton, with EAs of 2.062 and 2.16 eV. The rich spectroscopic and thermochemical data obtained in the current study make the CNN radical anions and their deprotonated species interesting systems for investigation in gas-phase, negative-ion experiments.

4.
Exp Hematol ; 136: 104280, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39009276

RESUMEN

Hematopoietic stem cells (HSCs) are a population of tissue-specific stem cells that reside in the bone marrow of adult mammals, where they self-renew and continuously regenerate the adult hematopoietic lineages over the life of the individual. Prominence as a stem cell model and clinical usefulness have driven interest in understanding the physiologic processes that lead to the specification of HSCs during embryonic development. High-efficiency directed differentiation of HSCs by the instruction of defined progenitor cells using sequentially defined instructive molecules and conditions remains impossible, indicating that comprehensive knowledge of the complete set of precursor intermediate identities and required inductive inputs remains incompletely understood. Recently, interest in the molecular and cellular microenvironment where HSCs are specified from endothelial precursors-the "specification niche"-has increased. Here we review recent progress in understanding these niche spaces across vertebrate phyla, as well as how a better characterization of the origin and molecular phenotypes of the niche cell populations has helped inform and complicate previous understanding of signaling required for HSC emergence and maturation.


Asunto(s)
Diferenciación Celular , Células Madre Hematopoyéticas , Nicho de Células Madre , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Animales , Humanos , Linaje de la Célula , Transducción de Señal , Hematopoyesis
5.
J Hosp Infect ; 149: 119-125, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38723904

RESUMEN

BACKGROUND: Interview and questionnaire studies have identified barriers and challenges to preventing surgical site infections (SSIs) by focusing on compliance with recommendations and care bundles using interviews, questionnaires and expert panels. This study proposes a more comprehensive investigation by using observations of clinical practice plus interviews which will enable a wider focus. AIM: To comprehensively identify the factors which affect SSI prevention using cardiac surgery as an exemplar. METHODS: The study consisted of 130 h of observed clinical practice followed by individual semi-structured interviews with 16 surgeons, anaesthetists, theatre staff, and nurses at four cardiac centres in England. Data were analysed thematically. FINDINGS: The factors were complex and existed at the level of the intervention, the individual, the team, the organization, and even the wider society. Factors included: the attributes of the intervention; the relationship between evidence, personal beliefs, and perceived risk; power and hierarchy; leadership and culture; resources; infrastructure; supplies; organization and planning; patient engagement and power; hospital administration; workforce shortages; COVID-19 pandemic; 'Brexit'; and the war in Ukraine. CONCLUSION: This is one of the first studies to provide a comprehensive overview of the factors affecting SSI prevention. The factors are complex and need to be fully understood when trying to reduce SSIs. A strong evidence base was insufficient to ensure implementation of an intervention.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Entrevistas como Asunto , Infección de la Herida Quirúrgica , Humanos , Infección de la Herida Quirúrgica/prevención & control , Infección de la Herida Quirúrgica/epidemiología , Inglaterra , Control de Infecciones/métodos , Control de Infecciones/normas , COVID-19/prevención & control , COVID-19/epidemiología , Investigación Cualitativa , Encuestas y Cuestionarios
6.
J Anal Toxicol ; 48(4): 210-216, 2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38581653

RESUMEN

Monofluoroacetate is a highly lethal toxin that causes death by inhibiting cellular adenosine triphosphate (ATP) production. The heart and brain are the primary target organs. Acute death is attributed to cardiac fibrillation and/or convulsions. Although it occurs naturally in some plants, a major source of animal intoxication is access to sodium monofluoroacetate (NaMFA) pesticide, which continues to be a concern in the USA and around the world despite restricted use in some countries including the USA. There are also concerns about misuse of this pesticide for malicious poisoning. Currently, a tissue-based diagnostic method for NaMFA intoxication in animals is lacking. There is a critical need by the veterinary diagnostic community for a simple, sensitive and reliable tissue-based diagnostic test to confirm NaMFA poisoning in animals. We have developed and extensively evaluated a sensitive novel liquid chromatography combined with tandem mass spectrometry method suitable for this purpose. The limits of detection and limits of quantitation are 1.7 and 5.0 ng/g, respectively. The accuracy and precision met or exceeded expectations. The method performance was verified using the incurred kidney obtained from animal diagnostic cases. This novel kidney-based method is now available for clinical use and can help with diagnostic purposes, including detecting potential issues related to animal foods.


Asunto(s)
Fluoroacetatos , Riñón , Espectrometría de Masas en Tándem , Fluoroacetatos/envenenamiento , Animales , Riñón/metabolismo , Cromatografía Liquida , Límite de Detección , Reproducibilidad de los Resultados , Cromatografía Líquida con Espectrometría de Masas
7.
J Phys Chem A ; 128(10): 1837-1852, 2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38437617

RESUMEN

Isomer-specific negative ion photoelectron spectra (NIPES) of cyanoindene (C9H7CN) and cyanofluorene (C14H9N), acquired through the computation of Franck-Condon (FC) factors that utilize harmonic vibrational frequencies and normal mode vectors derived from density functional theory (DFT) at the B3LYP/aug-cc-pVQZ and 6-311++G(2d,2p) basis sets, are reported. The adiabatic electron affinity (EA) values of the ground singlet (S0) and the lowest lying triplet (T1) states are used to predict site-specific S0-T1 energies (ΔEST). The vibrational spectra of the S0 and T1 states are typified by ring distortion and ring C-C stretching vibrational progressions. Among all the S0 isomers in C9H7CN, the 2-cyanoindene (2-C9H7CN) is found to be the most stable at an EA of 0.716 eV, with the least stable isomer being the 1-C9H7CN at an EA of 0.208 eV. In C14H9N, the most stable S0 isomer, 2-cyanofluorene (2-C14H9N), has an EA of 0.781 eV. The least stable S0 isomer in C14H9N is the 9-C14H9N, with an EA of 0.364 eV. The FC calculations are designed to mimic simulations that would be performed to aid in the analysis of experimental spectra obtained in NIPE spectroscopic techniques. The vibrational spectra, adiabatic EAs, and ΔEST values reported in this study are intended to act as a guide for future gas-phase ion spectroscopic experiments and astronomical searches, especially with regard to the hitherto largely unexplored C14H9N isomers.

9.
J Zoo Wildl Med ; 54(4): 713-720, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38251994

RESUMEN

The Humboldt penguin (Spheniscus humboldti) population at the Punta San Juan Marine Protected Area in Peru is considered critical to the long-term sustainability of this endangered species in Peru. Exposure of the rookery to environmental toxicants is a mounting concern because of regional growth of industries and human populations. Whole blood samples were collected from 30 free-ranging penguins in 2011 as part of a broader population health monitoring program. Dried blood spots (DBS) containing 50 µl of blood were prepared and analyzed to assess exposure to five groups of environmental contaminants. Concentrations of elements arsenic, cadmium, iron, lead, mercury, selenium, and thallium were analyzed using inductively coupled plasma mass spectrometry. Persistent organic pollutant concentrations were measured using gas chromatography-tandem mass spectrometry to analyze organochlorine pesticides (OCP; p,p'-DDT, p,p'-DDE, ß-hexachlorocyclohexane, t-nonachlor, and oxychlordane), polychlorinated biphenyls (congeners 138 and 153), and polybrominated flame retardants (polybrominated biphenyl-153 and polybrominated diphenyl ether congeners 47 and 99). Per- and polyfluoroalkyl substances, including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid were measured using liquid chromatography-tandem mass spectrometry. Results revealed low levels of exposure to these selected contaminants, at levels not considered to be of concern for wildlife health. DBS methodology was considered effective in a field-based setting for quantification of whole blood concentrations of environmental contaminants in penguins.


Asunto(s)
Spheniscidae , Animales , Humanos , Perú , Contaminantes Orgánicos Persistentes , Animales Salvajes , Cromatografía Liquida/veterinaria , DDT , Diclorodifenil Dicloroetileno
10.
Occup Med (Lond) ; 74(1): 120-127, 2024 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-38029429

RESUMEN

BACKGROUND: Healthcare workers were a priority group for coronavirus disease 2019 (COVID-19) vaccination during the pandemic. Occupational exposure may account for some of the increased risk faced. AIMS: Describe COVID-19 vaccine uptake and infection rates in staff across a large NHS board in Scotland to better understand occupational risk during the pandemic. METHODS: Descriptive cross-sectional study. Demographic data were extracted on 5 August 2021 from 26 058 members of staff. COVID-19 vaccination status and positive polymerase chain reaction (PCR) results were extracted on two separate dates to describe the timeline of staff infections between March 2020 and January 2022. RESULTS: There was high uptake of all three vaccine doses across all demographic groups in hospital staff. PCR positivity decreased with increasing age and Scottish Index of Multiple Deprivation score. Staff and nosocomial COVID-19 infections followed peaks in community infection rates. CONCLUSIONS: NHS Lothian is a typical NHS workforce with good vaccine uptake. Beyond very early cases, there seems to be minimal evidence of occupational acquisition of COVID-19. The large number of nosocomial infections at the start of the pandemic may, in fact, reflect lack of community testing at this time. Despite protection from high vaccine coverage, job type and good Infection Prevention and Control practices, it seems that staff remain at high risk of catching the highly transmissible omicron variant from the community rather than work.


Asunto(s)
COVID-19 , Infección Hospitalaria , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Estudios Transversales , Medicina Estatal , SARS-CoV-2 , Vacunación , Personal de Hospital , Recursos Humanos
11.
Nutr Rev ; 82(2): 193-209, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-37290429

RESUMEN

CONTEXT: There is substantial evidence that reduced short-chain fatty acids (SCFAs) in the gut are associated with obesity and type 2 diabetes, although findings from clinical interventions that can increase SCFAs are inconsistent. OBJECTIVE: This systematic review and meta-analysis aimed to assess the effect of SCFA interventions on fasting glucose, fasting insulin, and homeostatic model assessment of insulin resistance (HOMA-IR). DATA SOURCES: Relevant articles published up to July 28, 2022, were extracted from PubMed and Embase using the MeSH (Medical Subject Headings) terms of the defined keywords [(short-chain fatty acids) AND (obesity OR diabetes OR insulin sensitivity)] and their synonyms. Data analyses were performed independently by two researchers who used the Cochrane meta-analysis checklist and the PRISMA guidelines. DATA EXTRACTION: Clinical studies and trials that measured SCFAs and reported glucose homeostasis parameters were included in the analysis. Standardized mean differences (SMDs) with 95%CIs were calculated using a random-effects model in the data extraction tool Review Manager version 5.4 (RevMan 5.4). The risk-of-bias assessment was performed following the Cochrane checklist for randomized and crossover studies. DATA ANALYSIS: In total, 6040 nonduplicate studies were identified, 23 of which met the defined criteria, reported fasting insulin, fasting glucose, or HOMA-IR values, and reported change in SCFA concentrations post intervention. Meta-analyses of these studies indicated that fasting insulin concentrations were significantly reduced (overall effect: SMD = -0.15; 95%CI = -0.29 to -0.01, P = 0.04) in treatment groups, relative to placebo groups, at the end of the intervention. Studies with a confirmed increase in SCFAs at the end of intervention also had a significant effect on lowering fasting insulin (P = 0.008). Elevated levels of SCFAs, compared with baseline levels, were associated with beneficial effects on HOMA-IR (P < 0.00001). There was no significant change in fasting glucose concentrations. CONCLUSION: Increased postintervention levels of SCFAs are associated with lower fasting insulin concentrations, offering a beneficial effect on insulin sensitivity. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42021257248.


Asunto(s)
Diabetes Mellitus Tipo 2 , Resistencia a la Insulina , Humanos , Diabetes Mellitus Tipo 2/prevención & control , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Insulina , Obesidad , Glucosa , Ácidos Grasos Volátiles/uso terapéutico , Glucemia/análisis
12.
PLoS Genet ; 19(12): e1011102, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38117861

RESUMEN

Acute lymphoblastic leukemia/lymphoma (ALL) is the most common pediatric cancer and is a malignancy of T or B lineage lymphoblasts. Dysregulation of intracellular Ca2+ levels has been observed in patients with ALL, leading to improper activation of downstream signaling. Here we describe a new zebrafish model of B ALL, generated by expressing human constitutively active CaMKII (CA-CaMKII) in tp53 mutant lymphocytes. In this model, B cell hyperplasia in the kidney marrow and spleen progresses to overt leukemia/lymphoma, with only 29% of zebrafish surviving the first year of life. Leukemic fish have reduced productive genomic VDJ recombination in addition to reduced expression and improper splicing of ikaros1, a gene often deleted or mutated in patients with B ALL. Inhibiting CaMKII in human pre-B ALL cells induced cell death, further supporting a role for CaMKII in leukemogenesis. This research provides novel insight into the role of Ca2+-directed signaling in lymphoid malignancy and will be useful in understanding disease development and progression.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Niño , Animales , Humanos , Pez Cebra/genética , Proteína Quinasa Tipo 2 Dependiente de Calcio Calmodulina/genética , Calcio , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología
13.
Sci Rep ; 13(1): 18129, 2023 10 24.
Artículo en Inglés | MEDLINE | ID: mdl-37875542

RESUMEN

Changes in mitochondrial dynamics are often associated with dietary patterns, medical treatments, xenobiotics, and diseases. Toxic exposures to hydrogen sulfide (H2S) harm mitochondria by inhibiting Complex IV and via other mechanisms. However, changes in mitochondrial dynamics, including morphology following acute exposure to H2S, are not yet fully understood. This study followed mitochondrial morphology changes over time after a single acute LCt50 dose of H2S by examining electron microscopy thalami images of surviving mice. Our findings revealed that within the initial 48 h after H2S exposure, mitochondrial morphology was impaired by H2S, supported by the disruption and scarcity of the cristae, which are required to enhance the surface area for ATP production. At the 72-h mark point, a spectrum of morphological cellular changes was observed, and the disordered mitochondrial network, accompanied by the probable disruption of mitophagy, was tied to changes in mitochondrial shape. In summary, this study sheds light on how acute exposure to high levels of H2S triggers alterations in mitochondrial shape and structure as early as 24 h that become more evident at 72 h post-exposure. These findings underscore the impact of H2S on mitochondrial function and overall cellular health.


Asunto(s)
Sulfuro de Hidrógeno , Ratones , Animales , Sulfuro de Hidrógeno/metabolismo , Mitocondrias/metabolismo , Complejo IV de Transporte de Electrones/metabolismo , Encéfalo/metabolismo
14.
J Hosp Infect ; 141: 112-118, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37734675

RESUMEN

BACKGROUND: Surgical site infection (SSI) surveillance aims to facilitate a reduction in SSIs through identifying infection rates, benchmarking, triggering clinical review and instituting infection control measures. Participation in surveillance is, however, variable suggesting opportunities to improve wider adoption. AIM: To gain an in-depth understanding of the barriers and facilitators for SSI surveillance in a high-income European setting. METHODS: Key informant interviews with 16 surveillance staff, infection prevention staff, nurses and surgeons from nine cardiac hospitals in England. Data were analysed thematically. FINDINGS: SSI surveillance was reported to be resource intensive. Barriers to surveillance included challenges associated with data collection: data being located in numerous places, multiple SSI data reporting schemes, difficulty in finding denominator data, lack of interface between computerized systems, 'labour intensive' or 'antiquated' methods to collect data (e.g., using postal systems for patient questionnaires). Additional reported concerns included: relevance of definitions, perceived variability in data reporting, lack of surgeon engagement, unsupportive managers, low priority of SSIs among staff, and a 'blame culture' around high SSI rates. Facilitators were increased resources, better use of digital technologies (e.g., remote digital wound monitoring), integrating surveillance within routine clinical work, having champions, mandating surveillance, ensuring a closer relationship between surveillance and improved patient outcomes, increasing the focus on post-discharge surveillance, and integration with primary care data. CONCLUSION: Using novel interviews with 'front-line' staff, identified opportunities for improving participation in SSI surveillance. Translating these findings into action will increase surveillance activity and bring patient safety benefits to a larger pool of surgical patients.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Infección de la Herida Quirúrgica , Humanos , Adulto , Infección de la Herida Quirúrgica/epidemiología , Infección de la Herida Quirúrgica/prevención & control , Cuidados Posteriores , Alta del Paciente , Control de Infecciones/métodos
15.
Mov Disord Clin Pract ; 10(Suppl 2): S9-S17, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37637980
16.
J Phys Chem B ; 127(27): 6091-6101, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37399503

RESUMEN

Complementary X-ray absorption fine structure (XAFS) spectroscopy and Raman spectroscopy studies were conducted on several UCl3 concentrations in several chloride salt compositions. The samples were 5% UCl3 in LiCl (S1), 5% UCl3 in KCl (S2), 5% UCl3 in LiCl-KCl eutectic (S3), 5% UCl3 in LiCl-KCl eutectic (S4), 50% UCl3 in KCl (S5), and 20% UCl3 in KCl (S6) molar concentrations. Sample S3 had UCl3 sourced from Idaho National Laboratory (INL), and all other samples were UCl3 sourced from TerraPower. The initial compositions were prepared in an inert and oxygen-free atmosphere. XAFS measurements were performed in the atmosphere at a beamline, and Raman spectroscopy was conducted inside a glovebox. Raman spectra were able to confirm initial UCl3. XAFS and later Raman spectra measured, however, did not correctly match the literature and computational spectra for the prepared UCl3 salt. Rather, the data shows some complex uranium oxychloride phases at room temperature that transition into uranium oxides upon heating. Oxygen pollution due to failure of the sealing mechanism can result in oxidation of the UCl3 salts. The oxychlorides present may be both a function of the unknown O2 exposure concentration, depending on the source of the leak and the salt composition. Evidence of this oxychloride claim and its subsequent decomposition is justified in this work.

17.
bioRxiv ; 2023 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-37503202

RESUMEN

The sclerotome in vertebrates comprises an embryonic population of cellular progenitors that give rise to diverse adult tissues including the axial skeleton, ribs, intervertebral discs, connective tissue, and vascular smooth muscle. In the thorax, this cell population arises in the ventromedial region of each of the segmented tissue blocks known as somites. How and when sclerotome adult tissue fates are specified and how the gene signatures that predate those fates are regulated has not been well studied. We have identified a previously unknown role for Ca 2+ /calmodulin-dependent protein kinase II (CaMKII) in regulating sclerotome patterning in zebrafish. Mechanistically, CaMKII regulates the activity of parallel signaling inputs that pattern sclerotome gene expression. In one downstream arm, CaMKII regulates distribution of the established sclerotome-inductive morphogen sonic hedgehog (Shh), and thus Shh-dependent sclerotome genes. In the second downstream arm, we show a previously unappreciated inductive requirement for Bmp signaling, where CaMKII activates expression of bmp4 and consequently Bmp activity. Bmp activates expression of a second subset of stereotypical sclerotome genes, while simultaneously repressing Shh-dependent markers. Our work demonstrates that CaMKII promotes parallel Bmp and Shh signaling as a mechanism to first promote global sclerotome specification, and that these pathways subsequently regionally activate and refine discrete compartmental genetic programs. Our work establishes how the earliest unique gene signatures that likely drive distinct cell behaviors and adult fates arise within the sclerotome.

18.
Methods Mol Biol ; 2678: 117-134, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37326708

RESUMEN

Diabetic retinopathy (DR) is a vascular complication of diabetes that can lead to partial or complete loss of vision. Early detection and treatment of DR can prevent blindness. Regular clinical examination is recommended for DR diagnosis; however, it is not always possible or feasible due to limited resources, expertise, time, and infrastructure. Several clinical and molecular biomarkers are proposed for the prediction of DR including microRNAs. MicroRNAs are a class of small non-coding RNAs that are found in biofluids and can be measured using reliable and sensitive methods. The most commonly used biofluid for microRNA profiling is plasma or serum; however, tear fluid (tears) is also demonstrated to contain microRNAs. MicroRNAs isolated from tears present a non-invasive source for DR detection. Different methods of microRNA profiling are available including digital PCR-based methods that can detect up to a single copy of microRNA in the biofluids. Here, we describe microRNA isolation from tears using manual method as well as using a high-throughput automated platform followed by microRNA profiling using digital PCR system.


Asunto(s)
Diabetes Mellitus , Retinopatía Diabética , MicroARNs , Humanos , Retinopatía Diabética/diagnóstico , Retinopatía Diabética/genética , MicroARNs/genética , MicroARNs/análisis , Diagnóstico Precoz , Lágrimas/química , Biomarcadores/análisis
19.
J Phys Chem A ; 127(18): 4063-4076, 2023 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-37116201

RESUMEN

In this work, the negative ion photoelectron spectra of 1-, 2-, and 9-cyanoanthracene (anthracenecarbonitrile, ACN) radical anions, obtained via the calculation of Franck-Condon (FC) factors based on a harmonic oscillator model, are reported. The FC calculations utilize harmonic vibrational frequencies and normal mode vectors derived from density functional theory using the B3LYP/6-311++G (2d,2p) basis set. The removal of an electron from the doublet anion allows for the computation of the negative ion photoelectron spectra that represents the neutral ground singlet state (So) and the lowest triplet state (T1) in each of the three ACN molecules. The respective adiabatic electron affinity (EA) values for the So state in 1-, 2-, and 9-ACN isomers are calculated to be 1.353, 1.360, and 1.423 eV. The calculated EA of the 9-cyanoanthracene singlet isomer is in close agreement with the previously reported experimental value of 1.27 ± 0.1 eV. Calculations show that the T1 states in 1-, 2-, and 9-ACN are located 1.656, 1.663, and 1.599 eV above the So state. The calculated T1 negative ion spectra exhibit intense vibrational origins and weak FC activity beyond the origins, indicating little change in geometry following electron detachment from the doublet anionic state. Upon deprotonation, the EA values of the radical isomers increase by ∼400-700 meV, resulting in neutral deprotonated radicals with EAs between 1.740 and 2.220 eV. The calculated site-specific gas-phase acidity values of ACN isomers indicate that ACN molecules are more acidic than benzonitrile.

20.
Toxicol Sci ; 2023 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-36882182

RESUMEN

Acute exposure to high concentrations of hydrogen sulfide (H2S) leads to sudden death and, if survived, lingering neurological disorders. Clinical signs include seizures, loss of consciousness, and dyspnea. The proximate mechanisms underlying H2S-induced acute toxicity and death have not been clearly elucidated. We investigated electrocerebral, cardiac and respiratory activity during H2S exposure using electroencephalogram (EEG), electrocardiogram (EKG) and plethysmography. H2S suppressed electrocerebral activity and disrupted breathing. Cardiac activity was comparatively less affected. To test whether Ca2+ dysregulation contributes to H2S-induced EEG suppression, we developed an in vitro real-time rapid throughput assay measuring patterns of spontaneous synchronized Ca2+ oscillations in cultured primary cortical neuronal networks loaded with the indicator Fluo-4 using the fluorescent imaging plate reader (FLIPR-Tetra®). Sulfide >5 ppm dysregulated synchronous calcium oscillation (SCO) patterns in a dose-dependent manner. Inhibitors of NMDA and AMPA receptors magnified H2S-induced SCO suppression. Inhibitors of L-type voltage gated Ca2+ channels and transient receptor potential channels prevented H2S-induced SCO suppression. Inhibitors of T-type voltage gated Ca2+ channels, ryanodine receptors, and sodium channels had no measurable influence on H2S-induced SCO suppression. Exposures to > 5 ppm sulfide also suppressed neuronal electrical activity in primary cortical neurons measured by multi-electrode array (MEA), an effect alleviated by pretreatment with the nonselective transient receptor potential channel inhibitor, 2-APB. 2-APB also reduced primary cortical neuronal cell death from sulfide exposure. These results improve our understanding of the role of different Ca2+ channels in acute H2S-induced neurotoxicity and identify transient receptor potential channel modulators as novel structures with potential therapeutic benefits.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...