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The barramundi (Lates calcarifer), a significant aquaculture species, typically displays silver to bronze coloration. However, attention is now drawn to rare variants like the "panda" phenotype, characterized by blotch-like patterns of black (PB) and golden (PG) patches. This phenotype presents an opportunity to explore the molecular mechanisms underlying color variations in teleosts. Unlike stable color patterns in many fish, the "panda" variant demonstrates phenotypic plasticity, responding dynamically to unknown cues. We propose a complex interplay of genetic factors and epigenetic modifications, focusing on DNA methylation. Through a multiomics approach, we analyze transcriptomic and methylation patterns between PB and PG patches. Our study reveals differential gene expression related to melanosome trafficking and chromatophore differentiation. Although the specific gene responsible for the PB-PG difference remains elusive, candidate genes like asip1, asip2, mlph, and mreg have been identified. Methylation emerges as a potential contributor to the "panda" phenotype, with changes in gene promoters like hand2 and dynamin possibly influencing coloration. This research lays the groundwork for further exploration into rare barramundi color patterns, enhancing our understanding of color diversity in teleosts. Additionally, it underscores the "panda" phenotype's potential as a model for studying adult skin coloration.
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The reactivity of the nitrate radical (NO3Ë) with organophosphorus and amidic actinide and lanthanide complexing agents of interest to nuclear solvent extraction applications was measured, resulting in the first-ever reported bimolecular rate constants for this radicals' reactions in dodecane solution. The order of reactivity for neutral organophosphorus compounds showed faster rate constants with increasing electron density on the phosphoryl phosphorus atom, indicating an increasing facility for electron abstraction reactions occurring in addition to H-atom abstraction from the ligand alkane chains. The only acidic organophosphorus compound investigated, HEH[EHP], showed low reactivity with the NO3Ë radical, attributed to its dimerization in this non-polar solvent. Amide ligand reaction rates were faster than for organophosphorus molecules, suggesting more facile H-atom abstraction from carbonyl activated methylene and amyl groups. While all rate constants were slower than the diffusion-limited rate they were still rapid enough to result in significant oxidation of solvent extraction ligands in dodecane solution.
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BACKGROUND: Acute coronary syndrome (ACS) is frequently accompanied by newly diagnosed atrial fibrillation (AF). AIMS: We aimed to compare the risk of major adverse cardiovascular events (MACE) in ACS patients presenting with known, newly diagnosed, or no AF. METHODS: In our multicentre, prospective registry study, we included patients with confirmed ACS. Patients are classified as having known, newly diagnosed or no AF. Newly diagnosed AF is subdivided according to the duration of the episode, time of onset, post-coronary artery bypass graft (CABG) or spontaneous occurrence, and treatment with oral anticoagulants (OAC). The primary endpoint is MACE at 1 year. Key secondary endpoints include ischaemic stroke and bleeding complications. RESULTS: Amongst 4,433 patients with confirmed ACS, 3,598 (81.2%) had no AF, 438 (9.9%) had newly diagnosed AF, and 397 (9.0%) had known AF. The rates of OAC treatment at discharge were 53.4% in patients with newly diagnosed AF and 89.2% in patients with known AF. After adjusting for baseline imbalances, only new AF was independently associated with increased rates of MACE, whereas known AF was not (hazard ratio [HR] 1.52, 95% confidence interval [CI]: 1.19-1.90 and HR 0.93, 95% CI: 0.70-1.23). For ACS patients with newly diagnosed AF, episodes lasting >24 hours were associated with a higher risk of MACE compared to episodes <24 hours (HR 1.99, 95% CI: 1.36-2.93). Episodes of new AF occurring post-CABG had more favourable outcomes compared to spontaneously occurring new AF (HR for MACE 0.52, 95% CI: 0.31-0.86). OAC treatment rates were higher in the new AF subcategories with higher rates of MACE and ischaemic stroke. CONCLUSIONS: Newly diagnosed AF in ACS patients was associated with higher rates of MACE and ischaemic stroke compared to ACS patients without or with known AF. Among the ACS patients with new AF, an episode lasting >24 hours was associated with worse outcomes than shorter episodes, while post-CABG occurrence of AF showed relatively better outcomes compared to spontaneously occurring AF. Only 53% of new AF patients were discharged on OAC therapy versus 89% with known AF.
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Síndrome Coronariana Aguda , Anticoagulantes , Fibrilação Atrial , Sistema de Registros , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/tratamento farmacológico , Fibrilação Atrial/complicações , Síndrome Coronariana Aguda/terapia , Síndrome Coronariana Aguda/complicações , Síndrome Coronariana Aguda/diagnóstico , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Estudos Prospectivos , Anticoagulantes/uso terapêutico , Ponte de Artéria Coronária/efeitos adversos , Resultado do Tratamento , Fatores de Risco , Idoso de 80 Anos ou mais , Hemorragia/induzido quimicamente , AVC Isquêmico/epidemiologia , AVC Isquêmico/etiologiaRESUMO
Soil microorganisms are pivotal in the global carbon cycle, but the viruses that affect them and their impact on ecosystems are less understood. In this study, we explored the diversity, dynamics, and ecology of soil viruses through 379 metagenomes collected annually from 2010 to 2017. These samples spanned the seasonally thawed active layer of a permafrost thaw gradient, which included palsa, bog, and fen habitats. We identified 5051 virus operational taxonomic units (vOTUs), doubling the known viruses for this site. These vOTUs were largely ephemeral within habitats, suggesting a turnover at the vOTU level from year to year. While the diversity varied by thaw stage and depth-related patterns were specific to each habitat, the virus communities did not significantly change over time. The abundance ratios of virus to host at the phylum level did not show consistent trends across the thaw gradient, depth, or time. To assess potential ecosystem impacts, we predicted hosts in silico and found viruses linked to microbial lineages involved in the carbon cycle, such as methanotrophy and methanogenesis. This included the identification of viruses of Candidatus Methanoflorens, a significant global methane contributor. We also detected a variety of potential auxiliary metabolic genes, including 24 carbon-degrading glycoside hydrolases, six of which are uniquely terrestrial. In conclusion, these long-term observations enhance our understanding of soil viruses in the context of climate-relevant processes and provide opportunities to explore their role in terrestrial carbon cycling.
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Metagenoma , Pergelissolo , Microbiologia do Solo , Vírus , Pergelissolo/microbiologia , Pergelissolo/virologia , Vírus/classificação , Vírus/genética , Vírus/isolamento & purificação , Ecossistema , Ciclo do Carbono , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificaçãoRESUMO
OBJECTIVE: Stable isotope studies have shown that hepatic de novo lipogenesis (DNL) plays an important role in the pathogenesis of intrahepatic lipid (IHL) deposition. Furthermore, previous research has demonstrated that fructose 1-phosphate (F1P) not only serves as a substrate for DNL, but also acts as a signalling metabolite that stimulates DNL from glucose. The aim of this study was to elucidate the mediators of F1P-stimulated DNL, with special focus on two key regulators of intrahepatic glucose metabolism, i.e., glucokinase regulatory protein (GKRP) and carbohydrate response element binding protein (ChREBP). METHODS: Aldolase B deficient mice (Aldob-/-), characterized by hepatocellular F1P accumulation, enhanced DNL, and hepatic steatosis, were either crossed with GKRP deficient mice (Gckr-/-) or treated with short hairpin RNAs directed against hepatic ChREBP. RESULTS: Aldob-/- mice showed higher rates of de novo palmitate synthesis from glucose when compared to wildtype mice (p < 0.001). Gckr knockout reduced de novo palmitate synthesis in Aldob-/- mice (p = 0.017), without affecting the hepatic mRNA expression of enzymes involved in DNL. In contrast, hepatic ChREBP knockdown normalized the hepatic mRNA expression levels of enzymes involved in DNL and reduced fractional DNL in Aldob-/- mice (p < 0.05). Of interest, despite downregulation of DNL in response to Gckr and ChREBP attenuation, no reduction in intrahepatic triglyceride levels was observed. CONCLUSIONS: Both GKRP and ChREBP mediate F1P-stimulated DNL in aldolase B deficient mice. Further studies are needed to unravel the role of GKRP and hepatic ChREBP in regulating IHL accumulation in aldolase B deficiency.
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Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Frutose-Bifosfato Aldolase , Lipogênese , Fígado , Camundongos Knockout , Triglicerídeos , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Camundongos , Fígado/metabolismo , Triglicerídeos/metabolismo , Frutose-Bifosfato Aldolase/metabolismo , Frutose-Bifosfato Aldolase/genética , Masculino , Camundongos Endogâmicos C57BL , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Glucose/metabolismo , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de TransporteRESUMO
Given the important role of patient-ventilator assessments in ensuring the safety and efficacy of mechanical ventilation, a team of respiratory therapists and a librarian used Grading of Recommendations, Assessment, Development, and Evaluation methodology to make the following recommendations: (1) We recommend assessment of plateau pressure to ensure lung-protective ventilator settings (strong recommendation, high certainty); (2) We recommend an assessment of tidal volume (VT) to ensure lung-protective ventilation (4-8 mL/kg/predicted body weight) (strong recommendation, high certainty); (3) We recommend documenting VT as mL/kg predicted body weight (strong recommendation, high certainty); (4) We recommend an assessment of PEEP and auto-PEEP (strong recommendation, high certainty); (5) We suggest assessing driving pressure to prevent ventilator-induced injury (conditional recommendation, low certainty); (6) We suggest assessing FIO2 to ensure normoxemia (conditional recommendation, very low certainty); (7) We suggest telemonitoring to supplement direct bedside assessment in settings with limited resources (conditional recommendation, low certainty); (8) We suggest direct bedside assessment rather than telemonitoring when resources are adequate (conditional recommendation, low certainty); (9) We suggest assessing adequate humidification for patients receiving noninvasive ventilation (NIV) and invasive mechanical ventilation (conditional recommendation, very low certainty); (10) We suggest assessing the appropriateness of the humidification device during NIV and invasive mechanical ventilation (conditional recommendation, low certainty); (11) We recommend that the skin surrounding artificial airways and NIV interfaces be assessed (strong recommendation, high certainty); (12) We suggest assessing the dressing used for tracheostomy tubes and NIV interfaces (conditional recommendation, low certainty); (13) We recommend assessing the pressure inside the cuff of artificial airways using a manometer (strong recommendation, high certainty); (14) We recommend that continuous cuff pressure assessment should not be implemented to decrease the risk of ventilator-associated pneumonia (strong recommendation, high certainty); and (15) We suggest assessing the proper placement and securement of artificial airways (conditional recommendation, very low certainty).
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Respiração Artificial , Volume de Ventilação Pulmonar , Humanos , Respiração Artificial/métodos , Respiração com Pressão Positiva/métodos , Respiração com Pressão Positiva/instrumentação , Ventiladores Mecânicos , Lesão Pulmonar Induzida por Ventilação Mecânica/prevenção & controleRESUMO
Hereditary fructose intolerance (HFI) is a painful and potentially lethal genetic disease caused by a mutation in aldolase B resulting in accumulation of fructose-1-phosphate (F1P). No cure exists for HFI and treatment is limited to avoid exposure to fructose and sugar. Using aldolase B deficient mice, here we identify a yet unrecognized metabolic event activated in HFI and associated with the progression of the disease. Besides the accumulation of F1P, here we show that the activation of the purine degradation pathway is a common feature in aldolase B deficient mice exposed to fructose. The purine degradation pathway is a metabolic route initiated by adenosine monophosphate deaminase 2 (AMPD2) that regulates overall energy balance. We demonstrate that very low amounts of fructose are sufficient to activate AMPD2 in these mice via a phosphate trap. While blocking AMPD2 do not impact F1P accumulation and the risk of hypoglycemia, its deletion in hepatocytes markedly improves the metabolic dysregulation induced by fructose and corrects fat and glycogen storage while significantly increasing the voluntary tolerance of these mice to fructose. In summary, we provide evidence for a critical pathway activated in HFI that could be targeted to improve the metabolic consequences associated with fructose consumption.
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AMP Desaminase , Intolerância à Frutose , Frutose-Bifosfato Aldolase , Frutose , Animais , Masculino , Camundongos , AMP Desaminase/genética , AMP Desaminase/metabolismo , Modelos Animais de Doenças , Metabolismo Energético/efeitos dos fármacos , Frutose/metabolismo , Intolerância à Frutose/metabolismo , Intolerância à Frutose/genética , Frutose-Bifosfato Aldolase/metabolismo , Frutose-Bifosfato Aldolase/genética , Frutosefosfatos/metabolismo , Hepatócitos/metabolismo , Hepatócitos/efeitos dos fármacos , Fígado/metabolismo , Hepatopatias/metabolismo , Hepatopatias/etiologia , Hepatopatias/genética , Camundongos Endogâmicos C57BL , Camundongos KnockoutRESUMO
This study offers a comprehensive morpho-histological analysis of the gastrointestinal tract (GIT) of the Malabar red snapper. A comparison of its GIT morphology with that of the Asian seabass reveals similarities and differences between the two species. Additionally, the moisture content, crude protein, and ash in the fillets of Malabar red snapper and Asian seabass were slightly different, with Malabar red snapper exhibiting higher levels of essential fatty acids. Furthermore, higher levels of the polyunsaturated fatty acid (PUFA)/saturated fatty acid (SFA) ratio and docosahexaenoic acid (DHA)/eicosapentaenoic acid (EPA) ratio, and a lower omega-6/omega-3 ratio, were observed in Malabar red snapper compared to Asian seabass. The Malabar red snapper's esophagus featured protective mechanisms such as simple columnar epithelial cells, mucous-secreting glands, and goblet cells that were predominantly stained for acid and neutral mucosubstances. Furthermore, its stomach, with mucus cells that were weakly stained for acid mucosubstances, exhibited distinct regions with varying glandular densities, with the pyloric region featuring few glands. The pyloric caeca of the fish were composed of five finger-like structures and few goblet cells. Several goblet cells gradually increased from the anterior to the posterior region of the intestine. These findings provide useful insights for the aquaculture sector, focusing on Malabar red snapper.
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Chronic exercise training is associated with an "athlete's artery" phenotype in young adults and an attenuated age-related decline in endothelium-dependent arterial function. Adolescence is associated with an influx of sex-specific hormones that may exert divergent effects on endothelial function, but whether training adaptations interact with biological maturation to produce a "youth athlete's artery" has not been explored. We investigated the influence of exercise-training status on endothelium-dependent arterial function during childhood and adolescence. Brachial artery flow-mediated dilation (FMD) was assessed in n = 102 exercise-trained (males, n = 25; females, n = 29) and untrained (males, n = 23; females, n = 25) youths, characterized as pre (males, n = 25; females, n = 26)- or post (males, n = 23; females, n = 28)-predicted age at peak height velocity (PHV). Baseline brachial artery diameter was larger in post- compared with pre-PHV youths (P ≤ 0.001), males compared with females (P ≤ 0.001), and trained compared with untrained youths (3.26 ± 0.51 vs. 3.11 ± 0.42 mm; P = 0.041). Brachial FMD was similar in pre- and post-PHV youths (P = 0.298), and males and females (P = 0.946). However, exercise-trained youths demonstrated higher FMD when compared with untrained counterparts (5.3 ± 3.3 vs. 3.0 ± 2.6%; P ≤ 0.001). Furthermore, brachial artery diameter (r2 = 0.142; P = 0.007 vs. r2 = 0.004; P = 0.652) and FMD (r2 = 0.138; P = 0.008 vs. r2 = 0.003; P = 0.706) were positively associated with cardiorespiratory fitness in post-, but not pre-PHV youths, respectively. Collectively, our data indicate that exercise training is associated with brachial artery remodeling and enhanced endothelial function during youth. However, arterial remodeling and endothelium-dependent function are only associated with elevated cardiorespiratory fitness during later stages of adolescence.NEW & NOTEWORTHY We report preliminary evidence of the "youth athlete's artery," characterized by training-related arterial remodeling and elevated endothelium-dependent arterial function in children and adolescents. However, training-related adaptations in brachial artery diameter and flow-mediated dilation (FMD) were associated with cardiorespiratory fitness in adolescents, but not in children. Our findings indicate that endothelium-dependent arterial function is modifiable with chronic exercise training during childhood, but the association between FMD and elevated cardiorespiratory fitness is only apparent during later stages of adolescence.
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Artéria Braquial , Exercício Físico , Vasodilatação , Humanos , Masculino , Feminino , Adolescente , Artéria Braquial/fisiologia , Artéria Braquial/diagnóstico por imagem , Criança , Exercício Físico/fisiologia , Endotélio Vascular/fisiologia , Fluxo Sanguíneo Regional , Adaptação Fisiológica , Atletas , Fatores EtáriosRESUMO
OBJECTIVE: Over recent years, there has been a growing interest in exploring the utility of seizure risk forecasting, particularly how it could improve quality of life for people living with epilepsy. This study reports on user experiences and perspectives of a seizure risk forecaster app, as well as the potential impact on mood and adjustment to epilepsy. METHODS: Active app users were asked to complete a survey (baseline and 3-month follow-up) to assess perspectives on the forecast feature as well as mood and adjustment. Post-hoc, nine neutral forecast users (neither agreed nor disagreed it was useful) completed semi-structured interviews, to gain further insight into their perspectives of epilepsy management and seizure forecasting. Non-parametric statistical tests and inductive thematic analyses were used to analyse the quantitative and qualitative data, respectively. RESULTS: Surveys were completed by 111 users. Responders consisted of "app users" (n = 58), and "app and forecast users" (n = 53). Of the "app and forecast users", 40 % believed the forecast was accurate enough to be useful in monitoring for seizure risk, and 60 % adopted it for purposes like scheduling activities and helping mental state. Feeling more in control was the most common response to both high and low risk forecasted states. In-depth interviews revealed five broad themes, of which 'frustrations with lack of direction' (regarding their current epilepsy management approach), 'benefits of increased self-knowledge' and 'current and anticipated usefulness of forecasting' were the most common. SIGNIFICANCE: Preliminary results suggest that seizure risk forecasting can be a useful tool for people with epilepsy to make lifestyle changes, such as scheduling daily events, and experience greater feelings of control. These improvements may be attributed, at least partly, to the improvements in self-knowledge experienced through forecast use.
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Convulsões , Humanos , Feminino , Masculino , Adulto , Convulsões/psicologia , Convulsões/diagnóstico , Pessoa de Meia-Idade , Adulto Jovem , Aplicativos Móveis , Previsões , Epilepsia/psicologia , Inquéritos e Questionários , Adolescente , Qualidade de Vida , Idoso , Risco , SeguimentosRESUMO
X-linked sideroblastic anemia (XLSA) and X-linked protoporphyria (XLPP) are uncommon diseases caused by loss-of-function and gain-of-function mutations, respectively, in the erythroid form of 5-aminolevulinic acid synthetase, ALAS2, which encodes the first enzyme in heme biosynthesis. A related sideroblastic anemia is due to mutations in SLC25A38, which supplies mitochondrial glycine for ALAS2 (SLC25A38-CSA). The lack of viable animal models has limited studies on the pathophysiology and development of therapies for these conditions. Here, using CRISPR-CAS9 gene editing technology, we have generated knock-in mouse models that recapitulate the main features of XLSA and XLPP, and, using conventional conditional gene targeting in embryonic stem cells, we also developed a faithful model of the SLC25A38-CSA. In addition to examining the phenotypes and natural history of each disease, we determine the effect of restriction or supplementation of dietary pyridoxine (vitamin B6), the essential cofactor of ALAS2, on the anemia and porphyria. In addition to the well-documented response of XLSA mutations to pyridoxine supplementation, we also demonstrate the relative insensitivity of the XLPP porphyria, severe sensitivity of the XLSA models, and an extreme hypersensitivity of the SLC25A38-CSA model to pyridoxine deficiency, a phenotype that is not shared with another mouse hereditary anemia model, Hbbth3/+ ï¢-thalassemia intermedia. Thus, in addition to generating animal models useful for examining the pathophysiology and treatment of these diseases, we have uncovered an unsuspected conditional synthetic lethality between the heme synthesis-related CSAs and pyridoxine deficiency. These findings have the potential to inform novel therapeutic paradigms for the treatment of these diseases.
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Infectious zoonotic disease emergence, through spillover events, is of global concern and has the potential to cause significant harm to society, as recently demonstrated by COVID-19. More than 70% of the 400 infectious diseases that emerged in the past five decades have a zoonotic origin, including all recent pandemics. There have been several approaches used to predict the risk of spillover through some of the known or suspected infectious disease emergence drivers, largely using correlative approaches. Here, we predict the spatial distribution of spillover risk by approximating general transmission through animal and human interactions. These mass action interactions are approximated through the multiplication of the spatial distribution of zoonotic virus diversity and human population density. Although our results indicate higher risk in regions along the equator and in Southeast Asia where both virus diversity and human population density are high, it should be noted that this is primarily a conceptual exercise. We compared our spillover risk map to key factors, including the model inputs of zoonotic virus diversity estimate map, human population density map, and the spatial distribution of species richness. Despite the limitations of this approach, this viral spillover map is a step towards developing a more comprehensive spillover risk prediction system to inform global monitoring.
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RAF inhibitors have transformed treatment for BRAF V600-mutant cancer patients, but clinical benefit is limited by adaptive induction of ERK signaling, genetic alterations that induce BRAF V600 dimerization, and poor brain penetration. Next-generation pan-RAF dimer inhibitors are limited by narrow therapeutic index. PF-07799933 (ARRY-440) is a brain-penetrant, selective, pan-mutant BRAF inhibitor. PF-07799933 inhibited signaling in vitro, disrupted endogenous mutant-BRAF:wild-type-CRAF dimers, and spared wild-type ERK signaling. PF-07799933 ± binimetinib inhibited growth of mouse xenograft tumors driven by mutant BRAF that functions as dimers and by BRAF V600E with acquired resistance to current RAF inhibitors. We treated patients with treatment-refractory BRAF-mutant solid tumors in a first-in-human clinical trial (NCT05355701) that utilized a novel, flexible, pharmacokinetics-informed dose escalation design that allowed rapid achievement of PF-07799933 efficacious concentrations. PF-07799933 ± binimetinib was well-tolerated and resulted in multiple confirmed responses, systemically and in the brain, in BRAF-mutant cancer patients refractory to approved RAF inhibitors.
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Pulse oximetry is arguably the most impactful monitor ever introduced into respiratory care practice. Recently there has been increased attention to the problem of occult hypoxemia in which patients are hypoxemic despite an acceptable SpO2 Although occult hypoxemia might be greater in Black patients than white patients, it is not insignificant in whites. In a given population of patients, the bias between SpO2 and arterial oxygen saturation (SaO2 ) might be close to zero. However, the limits of agreement can be wide, meaning that SpO2 might overestimate SaO2 in many individual patients, which can result in occult hypoxemia in some. Manufactures report accuracy of SpO2 derived from normal individuals, which might differ from that in the clinical setting. That SpO2 overestimates SaO2 in an important number of individuals has caused some to recommend higher SpO2 targets to avoid occult hypoxemia. There is also evidence that suggests that SpO2 might not accurately trend SaO2 Additional research is needed to investigate strategies to mitigate the bias between SpO2 and SaO2 Clinicians must be cognizant of the limitations of pulse oximetry when clinically using SpO2 The aim of this paper is to provide an update on pulse oximetry.
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Hipóxia , Oximetria , Saturação de Oxigênio , Oximetria/métodos , Humanos , Hipóxia/diagnóstico , Hipóxia/sangue , Saturação de Oxigênio/fisiologia , Oxigênio/sangueRESUMO
Over the past forty years there has been a drastic increase in fructose-related diseases, including obesity, heart disease and diabetes. Ketohexokinase (KHK), the first enzyme in the liver fructolysis pathway, catalyzes the ATP-dependent phosphorylation of fructose to fructose 1-phosphate. Understanding the role of KHK in disease-related processes is crucial for the management and prevention of this growing epidemic. Molecular insight into the structure-function relationship in ligand binding and catalysis by KHK is needed for the design of therapeutic inhibitory ligands. Ketohexokinase has two isoforms: ketohexokinase A (KHK-A) is produced ubiquitously at low levels, whereas ketohexokinase C (KHK-C) is found at much higher levels, specifically in the liver, kidneys and intestines. Structures of the unliganded and liganded human isoforms KHK-A and KHK-C are known, as well as structures of unliganded and inhibitor-bound mouse KHK-C (mKHK-C), which shares 90% sequence identity with human KHK-C. Here, a high-resolution X-ray crystal structure of mKHK-C refined to 1.79â Å resolution is presented. The structure was determined in a complex with both the substrate fructose and the product of catalysis, ADP, providing a view of the Michaelis-like complex of the mouse ortholog. Comparison to unliganded structures suggests that KHK undergoes a conformational change upon binding of substrates that places the enzyme in a catalytically competent form in which the ß-sheet domain from one subunit rotates by 16.2°, acting as a lid for the opposing active site. Similar kinetic parameters were calculated for the mouse and human enzymes and indicate that mice may be a suitable animal model for the study of fructose-related diseases. Knowledge of the similarity between the mouse and human enzymes is important for understanding preclinical efforts towards targeting this enzyme, and this ground-state, Michaelis-like complex suggests that a conformational change plays a role in the catalytic function of KHK-C.
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Frutoquinases , Animais , Frutoquinases/química , Frutoquinases/metabolismo , Camundongos , Cristalografia por Raios X , Isoenzimas/química , Modelos Moleculares , Conformação Proteica , Humanos , Frutose/metabolismo , Frutose/químicaRESUMO
Giant ichthyosaurs with body length estimates exceeding 20 m were present in the latest Triassic of the UK. Here we report on the discovery of a second surangular from the lower jaw of a giant ichthyosaur from Somerset, UK. The new find is comparable in size and morphology to a specimen from Lilstock, Somerset, described in 2018, but it is more complete and better preserved. Both finds are from the uppermost Triassic Westbury Mudstone Formation (Rhaetian), but the new specimen comes from Blue Anchor, approximately 10 km west along the coast from Lilstock. The more complete surangular would have been >2 m long, from an individual with a body length estimated at ~25 m. The identification of two specimens with the same unique morphology and from the same geologic age and geographic location warrants the erection of a new genus and species, Ichthyotitan severnensis gen. et sp. nov. Thin sections of the new specimen revealed the same histological features already observed in similar giant ichthyosaurian specimens. Our data also supports the previous suggestion of an atypical osteogenesis in the lower jaws of giant ichthyosaurs. The geological age and giant size of the specimens suggest shastasaurid affinities, but the material is too incomplete for a definitive referral. Ichthyotitan severnensis gen. et sp. nov., is the first-named giant ichthyosaur from the Rhaetian and probably represents the largest marine reptile formally described.
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Evolução Biológica , Fósseis , Animais , Filogenia , Répteis , Reino UnidoRESUMO
Statistical analysis is an important part of the research process. Researchers are advised to include a statistician from the moment that the study is being planned. The statistical plan informs the research process, including sample size requirements and the most robust data collection. Once the data are collected, descriptive and inferential statistical analyses are performed. The results of this analysis determine whether the findings are significant, which leads to an interpretation of the findings. The importance of the statistical plan and analysis for the researcher is self-evident. However, it is also important for the reader of published papers to have some knowledge of statistical analysis. This allows critical review of all aspects of the published manuscript. The intent of this paper is to review some basic statistical concepts and thus allow the reader to become a better consumer of the literature.
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Intenção , Projetos de Pesquisa , Humanos , Interpretação Estatística de Dados , Coleta de DadosRESUMO
Despite prior publications of clinical practice guidelines related to ventilator liberation, some questions remain unanswered. Many of these questions relate to the details of bedside implementation. We, therefore, formed a guidelines committee of individuals with experience and knowledge of ventilator liberation as well as a medical librarian. Using Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology, we make the following recommendations: (1) We suggest that calculation of a rapid shallow breathing index is not needed to determine readiness for a spontaneous breathing trial (SBT) (conditional recommendation; moderate certainty); (2) We suggest that SBTs can be conducted with or without pressure support ventilation (conditional recommendation, moderate certainty); (3) We suggest a standardized approach to assessment and, if appropriate, completion of an SBT before noon each day (conditional recommendation, very low certainty); and (4) We suggest that FIO2 should not be increased during an SBT (conditional recommendation, very low certainty). These recommendations are intended to assist bedside clinicians to liberate adult critically ill patients more rapidly from mechanical ventilation.
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Respiração Artificial , Desmame do Respirador , Humanos , Desmame do Respirador/métodos , Desmame do Respirador/normas , Adulto , Respiração Artificial/métodos , Respiração Artificial/normas , Respiração , Estado Terminal/terapiaRESUMO
To understand the speciation of solutes in aqueous solutions in high temperature radiation environments, we report the design and fabrication of a custom-built, high temperature (≤300 °C) titanium irradiation cell with in situ optical spectroscopy capabilities, as afforded by coupled fiber optic cables. The wetted surfaces of the 8-inch tall cylindrical cell with 3.5 in. diameter are entirely made of titanium, sapphire, and gold, which are chemically and radiolytically inert. The initial benchmarking results are reported, including the baseline spectrum of deionized water as a function of temperature, the stability of a spectrum over 4 h at 100 °C, and an irradiated Fricke dosimetry solution under ambient irradiator temperature conditions (27.0 ± 0.5 °C). The average gamma radiation dose rate in the cell in its current configuration is 26.1 ± 1.3 Gy min-1. This cell has application in studying several processes throughout the nuclear fuel cycle, including the reactor coolant behavior.
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Shellfish allergy affects ~2.5% of the global population and is a type I immune response resulting from exposure to crustacean and/or molluscan proteins. The Australian Redclaw crayfish (Cherax quadricarinatus) is a freshwater species endemic to and farmed in northern Australia and is becoming an aquaculture species of interest globally. Despite being consumed as food, allergenic proteins from redclaw have not been identified or characterised. In addition, as different body parts are often consumed, it is conceivable that redclaw tissues vary in allergenicity depending on tissue type and function. To better understand food-derived allergenicity, this study characterised allergenic proteins in various redclaw body tissues (the tail, claw, and cephalothorax) and how the stability of allergenic proteins was affected through cooking (raw vs. cooked tissues). The potential of redclaw allergens to cross-react and cause IgE-binding in patients allergic to other shellfish (i.e., shrimp) was also investigated. Raw and cooked extracts were prepared from each body part. SDS-PAGE followed by immunoblotting was performed to determine allergen-specific antibody reactivity to sarcoplasmic calcium-binding protein and hemocyanin, as well as to identify redclaw proteins binding to IgE antibodies from individual and pooled sera of shrimp-allergic patients. Liquid chromatography-mass spectrometry (LC/MS) was utilised to identify proteins and to determine the proportion within extracts. Known crustacean allergens were found in all tissues, with a variation in tissue distribution (e.g., higher levels of hemocyanin in the claw and cephalothorax than in the tail). The proportion of some allergens as a percentage of remaining heat-stable proteins increased in cooked tissues. Previously described heat-stable allergens (i.e., hemocyanin and sarcoplasmic calcium-binding protein) were found to be partially heat-labile. Immunoblotting indicated that shrimp-allergic patients cross-react to redclaw allergens. IgE-binding bands, analysed by LC/MS, identified up to 11 known shellfish allergens. The findings of this study provide fundamental knowledge into the diagnostic and therapeutic field of shellfish allergy.