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Cobalt (Co) and Nickel (Ni) are used nowadays in various industrial applications like lithium-ion batteries, raising concerns about their environmental release and public health threats. Both metals are potentially carcinogenic and may cause neurological and cardiovascular dysfunctions, though underlying toxicity mechanisms have to be further elucidated. This study employs untargeted transcriptomics to analyze downstream cellular effects of individual and combined Co and Ni toxicity in human liver carcinoma cells (HepG2). The results reveal a synergistic effect of Co and Ni, leading to significantly higher number of differentially expressed genes (DEGs) compared to individual exposure. There was a clear enrichment of Nrf2 regulated genes linked to pathways such as glycolysis, iron and glutathione metabolism, and sphingolipid metabolism, confirmed by targeted analysis. Co and Ni exposure alone and combined caused nuclear Nrf2 translocation, while only combined exposure significantly affects iron and glutathione metabolism, evidenced by upregulation of HMOX-1 and iron storage protein FTL. Both metals impact sphingolipid metabolism, increasing dihydroceramide levels and decreasing ceramides, sphingosine and lactosylceramides, along with diacylglycerol accumulation. By combining transcriptomics and analytical methods, this study provides valuable insights into molecular mechanisms of Co and Ni toxicity, paving the way for further understanding of metal stress.
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Cobalto , Neoplasias Hepáticas , Factor 2 Relacionado con NF-E2 , Níquel , Transcriptoma , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/genética , Níquel/toxicidad , Cobalto/toxicidad , Transcriptoma/efectos de los fármacos , Células Hep G2 , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Perfilación de la Expresión Génica , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacosRESUMEN
BACKGROUND: The essential trace element copper is relevant for many important physiological processes. Changes in copper homeostasis can result from disease and affect human health. A reliable assessment of copper status by suitable biomarkers may enable fast detection of subtle changes in copper metabolism. To this end, additional biomarkers besides serum copper and ceruloplasmin (CP) concentrations are required. OBJECTIVES: The aim of this study was to investigate the emerging copper biomarkers CP oxidase (CPO) activity, exchangeable copper (CuEXC) and labile copper in serum of healthy women and compare them with the conventional biomarkers total serum copper and CP. METHOD AND MAIN FINDINGS: This observational study determined CPO activity, the non CP-bound copper species CuEXC and labile copper, total serum copper and CP in sera of 110 healthy women. Samples were collected at four time points over a period of 24 weeks. The concentrations of total serum copper and CP were within the reference ranges. The comparison of all five biomarkers provided insight into their relationship, the intra- and inter-individual variability as well as the age dependence. The correlation and Principal Component Analyses (PCA) indicated that CP, CPO activity and total copper correlated well, followed by CuEXC, while the labile copper pool was unrelated to the other parameters. CONCLUSIONS: This study suggests that the non-CP-bound copper species represent copper pools that are differently regulated from total copper or CP-bound copper, making them interesting complementary biomarkers to enable a more complete assessment of body copper status with potential relevance for clinical application.
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Biomarcadores , Cobre , Humanos , Cobre/sangre , Femenino , Biomarcadores/sangre , Adulto , Persona de Mediana Edad , Ceruloplasmina/metabolismo , Ceruloplasmina/análisis , Adulto Joven , Voluntarios Sanos , AncianoRESUMEN
The selective reduction of an aromatic trifluoromethyl substituent to a difluoromethyl substituent may be achieved by base-promoted elimination to form a difluoro-p-quinomethide which is trapped by an intramolecular nucleophile. High yields are obtained when the nucleophilic trap entails the conformationally favoured cyclisation of an aminoisobutyric acid (Aib) derivative. The resulting cyclised difluoromethyl-substituted arylimidazolidinone products are readily converted to versatile difluoromethyl-substituted aldehydes by reduction and hydrolysis. Defluorination is successful on a range of benzenoid (both para and ortho CF3-substituted) and heterocyclic substrates. Double defluorination may likewise be achieved sequentially, or in a single step, from an Aib dipeptide derivative.
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Allied health primary contact clinic models of care have increasingly been used as a strategy to increase public health service capacity. A recent systematic review found little consistency or agreement on how primary contact clinics are evaluated. The concept of value of primary contact clinics, which has important implications for evaluation, has not yet been explored in-depth. To explore allied health clinicians' perceptions of the value of allied health primary contact clinics, with the goal of informing an evaluation framework, a descriptive qualitative approach utilizing semi-structured interviews was employed. Participants included allied health staff embedded in clinical lead roles within primary contact clinics across four acute care hospitals in a metropolitan health service located in South-East Queensland, Australia. Lead staff from 30 identified primary contact clinic models in the health service were approached to take part via email. All eligible participants who provided consent were included. An inductive thematic analysis approach was used. A total of 23 clinicians (n = 23) representing 22 diverse models of primary contact clinics participated. Most participants were physiotherapists, dietitians, or occupational therapists, although speech pathology, audiology, and podiatry were also represented. Participant perceptions of the 'value' of PCCs were a highly complex phenomenon, comprising five intersecting domains: (i) patient satisfaction; (ii) clinical outcomes; (iii) care pathway and resource use; (iv) health service performance; and (v) staff satisfaction and professional standing. These five core value domains were positively or negatively influenced by 12 perceived benefits and 8 perceived drawbacks, respectively. Value domains were also highly interrelated and impacted upon each other. The concept of 'value' relating to primary contact clinics involves multiple intersecting domains encompassing different perspectives. This study highlighted potential benefits and drawbacks of primary contact clinics that have not yet been measured or explored in the literature, and as such may be useful for healthcare administrators to consider. The findings of this study will inform an evaluation framework including health economics calculator for primary contact clinics.
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Instituciones de Atención Ambulatoria , Pacientes , Humanos , Australia , Satisfacción del PacienteRESUMEN
INTRODUCTION: Therapeutic alliance is a relevant aspect of healthcare and may influence patient outcomes. So far, little is known about the therapeutic alliance in telerehabilitation. PURPOSE: To identify and describe central elements of therapeutic alliance in the setting of telerehabilitation and compare it to those in conventional rehabilitation. METHODS: In this qualitative study, a literature search and in-depth semi-structured interviews with rehabilitation and telerehabilitation experts were conducted from 15.5.-10.8.2020 on elements influencing the therapeutic alliance in rehabilitation and telerehabilitation. Using a combined deductive and inductive approach, qualitative content analysis was used to identify categories and derive central themes. RESULTS: The elements bond, communication, agreement on goals and tasks and external factors were identified in the literature search and informed the development of the interview guide. Twelve purposively sampled experts from the fields of physiotherapy, occupational therapy, speech and language therapy, psychology, general medicine, sports science and telerehabilitation software development participated in the interviews. We identified three central themes: building effective communication; nurturing a mutual relationship of trust and respect; and agreement on goals and tasks and drivers of motivation. CONCLUSIONS: In this qualitative study, key elements of therapeutic alliance in rehabilitation confirmed those reported in the literature, with additional elements in telerehabilitation comprising support from others for ensuring physical safety and technical connectedness, caregivers acting as co-therapists and applying professional touch, and promoting patient autonomy and motivation using specific strategies.
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Terapia Ocupacional , Telerrehabilitación , Alianza Terapéutica , Humanos , Telerrehabilitación/métodos , Investigación Cualitativa , Modalidades de FisioterapiaRESUMEN
BACKGROUND: Integrated speech-language pathology (SLP) services within the emergency department (ED) may facilitate timely dysphagia management. However, there are multiple patient and logistical factors specific to the ED that challenge the delivery of optimal dysphagia referral and management practices within this setting. The aim of the current study was to engage a stakeholder group to identify prioritised, actionable goals that could help enhance dysphagia management within the ED. METHODS AND PROCEDURES: Applying concept mapping methodology, 16 ED stakeholders from SLP, medical, nursing, and leadership participated in semi-structured interviews to develop action statements which were sorted and ranked for importance and changeability. Multidimensional scaling and hierarchical cluster analysis were used to organise data in clusters with unifying themes before statements were ranked by importance and changeability. OUTCOMES AND RESULTS: Stakeholders identified 53 unique statements, grouped into 8 clusters. Review of the 8 clusters identified 3 overarching aspects for change: (a) Improving processes related to identification and referral of patients as well as communication; (b) Teamwork and collaboration amongst the ED multidisciplinary team and SLP; and (c) Improving staffing and access to training resources for SLP and nursing teams. Seventeen statements were within the Go-zone rated highest for importance and changeability) with the highest rated statement being: Clear documentation by SLP re: recommendations. CONCLUSION: The current data identified multiple aspects of service provision that require change to facilitate improved dysphagia referral and management services in the ED. Collaborative actions are required by both SLP and the ED multidisciplinary team to help optimise dysphagia services.
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Trastornos de Deglución , Servicio de Urgencia en Hospital , Patología del Habla y Lenguaje , Trastornos de Deglución/terapia , Trastornos de Deglución/diagnóstico , Humanos , Servicio de Urgencia en Hospital/organización & administración , Patología del Habla y Lenguaje/métodos , Derivación y Consulta , Mejoramiento de la Calidad , Grupo de Atención al Paciente/organización & administración , Participación de los Interesados , Masculino , FemeninoRESUMEN
PURPOSE: To examine referral pathways, clinical demographics, and timeliness of dysphagia management within an emergency department (ED) setting utilising both ED staff and speech-language pathology (SLP) initiated referral pathways. METHOD: Six-month retrospective service review of patients who received dysphagia assessment by SLP within a major Australian ED. Data were collected on demographics, referral information, and SLP assessment and service outcomes. RESULT: Three hundred and ninety-three patients were assessed by SLP staff in the ED, consisting of 200 stroke and 193 non-stroke referrals. In the stroke cohort, 57.5% of referrals were initiated by ED staff, while 42.5% were SLP initiated. ED staff initiated 91% of non-stroke referrals, with few (9%) proactively identified by SLP staff. SLP staff identified a higher proportion of non-stroke patients within 4 hr of presentation compared to ED staff. Stroke patients identified by SLP staff were more likely to have assessments completed within 8 hr compared to the ED referral pathway. Collectively, 51% of patients required ongoing dysphagia management following initial assessment. CONCLUSION: Findings provide an overview of SLP services and referral pathways in an ED context. The SLP initiated referral pathway facilitated early assessment of stroke patients, and collaboration with ED staff was integral in referring other at risk populations. SLP/ED synergy is needed for appropriate and timely dysphagia management practices in an ED.
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Trastornos de Deglución , Patología del Habla y Lenguaje , Accidente Cerebrovascular , Humanos , Estudios Retrospectivos , Australia , Estudios LongitudinalesRESUMEN
Mitochondria play multifaceted roles in cellular function, and impairments across domains of mitochondrial biology are known to promote cellular integrated stress response (ISR) pathways as well as systemic metabolic adaptations. However, the temporal dynamics of specific mitochondrial ISR related to physiological variations in tissue-specific energy demands remains unknown. Here, we conducted a comprehensive 24-hour muscle and plasma profiling of male and female mice with ectopic mitochondrial respiratory uncoupling in skeletal muscle (mUcp1-transgenic, TG). TG mice are characterized by increased muscle ISR, elevated oxidative stress defense, and increased secretion of FGF21 and GDF15 as ISR-induced myokines. We observed a temporal signature of both cell-autonomous and systemic ISR in the context of endocrine myokine signaling and cellular redox balance, but not of ferroptotic signature which was also increased in TG muscle. We show a progressive increase of muscle ISR on transcriptional level during the active phase (night time), with a subsequent peak in circulating FGF21 and GDF15 in the early resting phase. Moreover, we found highest levels of muscle oxidative defense (GPX and NQO1 activity) between the late active to early resting phase, which could aim to counteract excessive iron-dependent lipid peroxidation and ferroptosis in muscle of TG mice. These findings highlight the temporal dynamics of cell-autonomous and endocrine ISR signaling under skeletal muscle mitochondrial uncoupling, emphasizing the importance of considering such dissociation in translational strategies and sample collection for diagnostic biomarker analysis.
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Ferroptosis , Ratones , Masculino , Femenino , Animales , Ratones Transgénicos , Mitocondrias/metabolismo , Músculo Esquelético/metabolismo , Oxidación-ReducciónRESUMEN
BACKGROUND: Electronic medical records (EMRs) have the potential to improve and streamline the quality and safety of patient care. Harnessing the full benefits of EMR implementation depends on the utilisation of advanced features, defined as "mature usage." At present, little is known about the maturity of EMR usage by allied health professionals (AHPs). OBJECTIVE: To examine current maturity of EMR use by AHPs and explore perceived barriers to mature EMR utilisation and optimisation. METHOD: AHPs were recruited from three health services. Participants completed a 27-question electronic questionnaire based on the EMR Adoption Framework, which measures clinician EMR utilisation (0 = paper chart, 5 = theoretical maximum) across 10 EMR feature categories. Interviews were conducted with both clinicians and managers to explore the nature of current EMR utilisation and perceived facilitators and barriers to mature usage. RESULTS: Questionnaire responses were obtained from 192 AHPs. The majority of questions (74%) showed a mean score of <3, indicating a lack of mature EMR use. Pockets of mature usage were identified in the categories of health information, referrals and administration processes. Interviews with 18 clinicians and managers revealed barriers to optimisation across three themes: (1) limited understanding of EMR opportunities; (2) complexity of the EMR change process and (3) end-user and environmental factors. CONCLUSION: Mature usage across EMR feature categories of the EMR Adoption Framework was low. However, questionnaire and qualitative interview data suggested pockets of mature utilisation. IMPLICATIONS: Achieving mature allied health EMR use will require strategies implemented at the clinician, EMR support, and service levels.
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Plant-based diets usually contain more nutrient-dense foods such as vegetables, legumes, whole grains, and fruits than a standard Western diet. Yet, the amount and especially the bioavailability of several nutrients, such as trace elements, is supposed to be lower in comparison to diets with consumption of animal-derived foods. Based on this, the Nutritional Evaluation (NuEva) study (172 participants) was initiated to compare the trace element status of omnivores, flexitarians, vegetarians, and vegans. Serum selenium, zinc, and copper concentrations and biomarkers were evaluated at baseline and during a 12-month intervention with energy- and nutrient-optimized menu plans. The implementation of optimized menu plans did not substantially influence the status of trace elements. At baseline, serum selenium biomarkers were lower in vegetarians and vegans compared to omnivores and flexitarians. The zinc intake of vegetarians and vegans was significantly lower compared to omnivores, whereas the Phytate Diet Score was increased. Accordingly, total serum zinc concentrations were reduced in vegans which was, however, only significant in women and was further supported by the analysis of free zinc. Regarding copper status, no differences were observed for total serum copper. Overall, we identified selenium and zinc as critical nutrients especially when maintaining a vegan diet.
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Selenio , Oligoelementos , Animales , Humanos , Veganos , Dieta Vegana , Cobre , Zinc , Vegetarianos , VerdurasRESUMEN
The use of nucleic acids (NAs) has revolutionized medical approaches and ushered in a new era of combating various diseases. Accordingly, there is an increasing demand for accurate identification, localization, quantification, and characterization of NAs encapsulated in nonviral or viral vectors. The vast spectrum of molecular dimensions and intra- and intermolecular interactions presents a formidable obstacle for NA analytical development. Typically, the comprehensive analysis of encapsulated NAs, free NAs, and their spatial distribution poses a challenge that is seldom tackled in its complete complexity. The identification of appropriate physicochemical methodologies for large nonencapsulated or encapsulated NAs is particularly intricate and necessitates an evaluation of the analytical outcomes and their appropriateness in addressing critical quality attributes. In this work, we examine the analytics of non-encapsulated or encapsulated large NAs (>500 nucleotides) utilizing capillary electrophoresis (CE) and liquid chromatography (LC) methodologies such as free zone CE, gel CE, affinity CE, and ion pair high-performance liquid chromatography (HPLC). These methodologies create a complete picture of the NA's critical quality attributes, including quantity, identity, purity, and content ratio.
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Background and aims: Preclinical data suggest that activation of the adaptive immune system is critical for myocardial repair processes in acute myocardial infarction. The aim of the present study was to determine the clinical value of baseline effector T cell chemokine IP-10 blood levels in the acute phase of ST-segment elevation myocardial infarction (STEMI) for the prediction of the left ventricular function changes and cardiovascular outcomes after STEMI. Methods: Serum IP-10 levels were retrospectively quantified in two independent cohorts of STEMI patients undergoing primary percutaneous coronary intervention. Results: We report a biphasic response of the effector T cell trafficking chemokine IP-10 characterized by an initial increase of its serum levels in the acute phase of STEMI followed by a rapid reduction at 90min post reperfusion. Patients at the highest IP-10 tertile presented also with more CD4 effector memory T cells (CD4 TEM cells), but not other T cell subtypes, in blood. In the Newcastle cohort (n=47), patients in the highest IP-10 tertile or CD4 TEM cells at admission exhibited an improved cardiac systolic function 12 weeks after STEMI compared to patients in the lowest IP-10 tertile. In the Heidelberg cohort (n=331), STEMI patients were followed for a median of 540 days for major adverse cardiovascular events (MACE). Patients presenting with higher serum IP-10 levels at admission had a lower risk for MACE after adjustment for traditional risk factors, CRP and high-sensitivity troponin-T levels (highest vs. rest quarters: HR [95% CI]=0.420 [0.218-0.808]). Conclusion: Increased serum levels of IP-10 in the acute phase of STEMI predict a better recovery in cardiac systolic function and less adverse events in patients after STEMI.
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Infarto del Miocardio , Infarto del Miocardio con Elevación del ST , Humanos , Quimiocina CXCL10 , Corazón , Estudios Retrospectivos , Infarto del Miocardio con Elevación del ST/terapiaRESUMEN
Selenium-binding protein 1 (SELENBP1) was reported to act as a methanethiol oxidase (MTO) in humans, catalyzing the conversion of methanethiol to hydrogen peroxide, hydrogen sulfide and formaldehyde. Here, we identify copper ions as essential to this novel MTO activity. Site-directed mutagenesis of putative copper-binding sites in human SELENBP1 produced as recombinant protein in E. coli resulted in loss of its enzymatic function. On the other hand, the eponymous binding of selenium (as selenite) was no requirement for MTO activity and only moderately increased SELENBP1-catalyzed oxidation of methanethiol. Furthermore, SEMO-1, the SELENBP1 ortholog recently identified in the nematode C. elegans, also requires copper ions, and MTO activity was enhanced or abrogated, respectively, if worms were grown in the presence of cupric chloride or of a Cu chelator. In addition to methanethiol, we identified novel substrates of SELENBP1 from the group of volatile sulfur compounds, ranging from ethanethiol to 1-pentanethiol as well as 2-propene-1-thiol. Gut microbiome-derived methanethiol as well as food-derived volatile sulfur compounds (VSCs) account for malodors that may contribute to extraoral halitosis in humans, if not metabolized properly. As SELENBP1 is particularly abundant in tissues exposed to VSCs, such as colon, liver, and lung, it appears to contribute to copper-dependent VSC degradation.
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Caenorhabditis elegans , Cobre , Animales , Humanos , Cobre/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Unión al Selenio/genética , Proteínas de Unión al Selenio/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Compuestos de Sulfhidrilo/metabolismo , Compuestos de Azufre/química , Oxidorreductasas/metabolismo , Ceruloplasmina/metabolismoRESUMEN
Selenium homeostasis depends on hepatic biosynthesis of selenoprotein P (SELENOP) and SELENOP-mediated transport from the liver to e.g. the brain. In addition, the liver maintains copper homeostasis. Selenium and copper metabolism are inversely regulated, as increasing copper and decreasing selenium levels are observed in blood during aging and inflammation. Here we show that copper treatment increased intracellular selenium and SELENOP in hepatocytes and decreased extracellular SELENOP levels. Hepatic accumulation of copper is a characteristic of Wilson's disease. Accordingly, SELENOP levels were low in serum of Wilson's disease patients and Wilson's rats. Mechanistically, drugs targeting protein transport in the Golgi complex mimicked some of the effects observed, indicating a disrupting effect of excessive copper on intracellular SELENOP transport resulting in its accumulation in the late Golgi. Our data suggest that hepatic copper levels determine SELENOP release from the liver and may affect selenium transport to peripheral organs such as the brain.
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Degeneración Hepatolenticular , Selenio , Animales , Ratas , Selenoproteína P , CobreRESUMEN
BACKGROUND: Trace elements exhibit essential functions in many physiological processes. Thus, for research focusing on trace element homeostasis and metabolism analytical methods allowing for multi-element analyses are fundamental. Small sample amounts may be a big challenge in trace element analyses especially if also other end points want to be addressed in the same sample. Therefore, the aim of the present study was to examine trace elements (iron, copper, zinc, and selenium) in murine liver tissue prepared by a RIPA buffer-based lyses method. METHODS AND RESULTS: After centrifugation, lysates and pellets were obtained and trace elements were analyzed with TXRF in liver lysates. The results were compared to that obtained by a standard microwave-assisted acidic digestion with subsequent ICP-MS/MS analysis of the same liver tissue, liver lysates, and remaining pellets. In addition, trace element concentrations, determined in murine serum with both methods, were compared. For serum samples, both TXRF and ICP-MS/MS provide similar and highly correlating results. Furthermore, in liver lysate samples prepared with RIPA buffer, comparable trace element concentrations were measured by TXRF as with the standard digestion technique and ICP-MS/MS. Only marginal amounts of trace elements were detected in the pellets. CONCLUSION: Taken together, the results obtained by the present study indicate that the RIPA buffer-based method is suitable for sample preparation for trace element analyses via TXRF, at least for the here investigated murine liver samples.
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Oligoelementos , Animales , Ratones , Oligoelementos/análisis , Espectrometría de Masas en Tándem , Cobre , Zinc , Hígado/químicaRESUMEN
Objective To utilise a concept mapping process to identify key opportunities for electronic medical record (EMR) optimisation for allied health professionals (AHPs). Methods A total of 26 participants (allied health managers, clinicians and healthcare consumers) completed the concept mapping process, which included generating statements, and then subsequently sorting all statements into groups, and also ranking each statement for importance and changeability (0 = not important/changeable, 4 extremely important/changeable). Multivariate analysis and multidimensional scaling were then used to identify core priorities for digital optimisation. Results Participants generated 98 discrete statements that were grouped into 13 conceptual clusters. Of these, 36 statements were subsequently determined to fall within the 'green zone' on the Go-Zone plot of importance and changeability (changeability ≥2.44, importance ≥2.79), and formed the set of key optimisation priorities. Clusters with the most items in the Go-Zone plot were 'training and business rules ' and 'service statistics .' Conclusion Concept mapping facilitated identification of 36 key optimisation priorities considered both changeable and important to assist EMR optimisation for AHPs. Addressing these priorities requires action related to end-user skills and training, EMR system capacity, and streamlining of governance and collaboration for the optimisation process.
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Atención a la Salud , Registros Electrónicos de Salud , Humanos , Análisis Multivariante , Instituciones de Salud , Técnicos Medios en SaludRESUMEN
The space of advanced therapeutic modalities is currently evolving in rapid pace necessitating continuous improvement of analytical quality control methods. In order to evaluate the identity of nucleic acid species in gene therapy products, we propose a capillary electrophoresis-based gel free hybridization assay in which fluorescently labeled peptide nucleic acids (PNAs) are applied as affinity probes. PNAs are engineered organic polymers that share the base pairing properties with DNA and RNA but have an uncharged peptide backbone. In the present study, we conduct various proof-of-concept studies to identify the potential of PNA probes for advanced analytical characterization of novel therapeutic modalities like oligonucleotides, plasmids, mRNA, and DNA released by recombinant adeno-associated virus. For single-stranded nucleic acids up to 1000 nucleotides, the method is an excellent choice that proved to be highly specific by detecting DNA traces in complex samples, while having a limit of quantification in the picomolar range when multiple probes are used. For double-stranded samples, only fragments that are similar in size to the probe could be quantified. This limitation can be circumvented when target DNA is digested and multiple probes are used opening an alternative to quantitative PCR.
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Ácidos Nucleicos de Péptidos , Ácidos Nucleicos de Péptidos/química , Hibridación de Ácido Nucleico , ADN/genética , ADN/química , ARN/química , Péptidos , Electroforesis Capilar/métodos , ARN MensajeroRESUMEN
A practical, transition metal-free method allows the enantioselective synthesis of α,α-diarylmethylamines by asymmetric α-arylation of benzylamines. Enantioselective lithiation of N'-aryl-N-benzyl-N-isopropyl ureas using a chiral lithium amide base generates a benzyllithium that undergoes an unactivated stereospecific intramolecular nucleophilic aromatic substitution to generate an α,α-diarylmethylamine in the form of its urea derivative, in up to >99 % ee. Treatment with acid induces an "azatropic shift" with retention of configuration, the product of which may be hydrolysed to the target amine.
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Five out of eight human glutathione peroxidases (GPXs) are selenoproteins, representing proteins that contain selenium as part of the amino acid selenocysteine. The GPXs are important for reducing hydroperoxides in a glutathione-consuming manner and thus regulate cellular redox homeostasis. GPX1, GPX2, and GPX4 represent the three main cytosolic GPXs, but they differ in their expression patterns with GPX1 and GPX4 being expressed ubiquitously, whereas GPX2 is mainly expressed in epithelial cells. GPX1 and GPX2 have been described to reduce soluble hydroperoxides, while GPX4 reduces complex lipid hydroperoxides, thus protecting cells from lipid peroxidation and ferroptosis. But most of these data are derived from cells that are devoid of one of the isoforms and thus, compensation or other cellular effects might affect the conclusions. So far, the use of isolated recombinant human selenoprotein glutathione peroxidases in pure enzyme assays has not been employed to study their substrate specificities side by side. Using recombinant GPX1, GPX2, and GPX4 produced in E. coli we here assessed their GPX activities by a NADPH-consuming glutathione reductase-coupled assay with 17 different peroxides (all at 50 µM) as substrates. GPX4 was clearly the only isoform able to reduce phosphatidylcholine hydroperoxide. In contrast, small soluble hydroperoxides such as H2O2, cumene hydroperoxide, and tert-butyl hydroperoxide were reduced by all three isoforms, but with approximately 10-fold higher efficiency for GPX1 in comparison to GPX2 and GPX4. Also, several fatty acid-derived hydroperoxides were reduced by all three isoforms and again GPX1 had the highest activity. Interestingly, the stereoisomerism of the fatty acid-derived hydroperoxides clearly affected the activity of the GPX enzymes. Overall, distinct substrate specificity is obvious for GPX4, but not so when comparing GPX1 and GPX2. Clearly GPX1 was the most potent isoform of the three GPXs in terms of turnover in reduction of soluble and fatty-acid derived hydroperoxides.
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Escherichia coli , Peróxido de Hidrógeno , Humanos , Escherichia coli/genética , Escherichia coli/metabolismo , Ácidos Grasos , Glutatión , Glutatión Peroxidasa/genética , Glutatión Peroxidasa/metabolismo , Peróxido de Hidrógeno/metabolismo , Especificidad por SustratoRESUMEN
PURPOSE: Timely speech-language pathology (SLP) involvement with dysphagic patients in the Emergency Department (ED) may improve patient outcomes. This study utilised qualitative interviews to understand current models and explore factors which have influenced establishment and current dysphagia service provision in Australian EDs. METHOD: Semi-structured interviews were conducted with representatives from 12 acute hospital facilities with a SLP ED service. Interview transcripts were analysed using plain content analysis to identify key themes. Sub-analysis using the Consolidated Framework for Implementation Research (CFIR) model was undertaken for facilities with more "expanded" models (n = 4). RESULT: SLP ED service models ranged from referral-only services, to models with referral-only and proactive SLP-led screening procedures (classified as "expanded"). Patient-related factors, the ED setting, SLP service factors and perceptions of dysphagia management were key themes reported to impact service delivery. With expanded models, 14 CFIR constructs (innovation source, external policy and incentives, networks and communications, stakeholders and relative priority) were identified as facilitators, while four constructs (adaptability, cost, compatibility, available resources) were barriers to services. CONCLUSION: There are service-specific issues with providing SLP care within the ED. Factors related to the unique ED environment must be considered by SLP departments when establishing/optimising dysphagia management within the ED.