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Background: Digital health literacy (DHL) enables healthy decisions, improves protective behaviors and adherence to COVID-19 measures, especially during the era of the "infodemic", and enhances psychological well-being. Objective: We aimed to explore the mediating roles of fear of COVID-19, information satisfaction, and the importance of online information searching on the association between DHL and well-being. Methods: A cross-sectional web-based survey was conducted among 1631 Taiwanese university students, aged 18 years and above, from June 2021 to March 2022. The collected data include sociodemographic characteristics (sex, age, social status, and financial satisfaction), the importance of online information searching, information satisfaction, fear of COVID-19, DHL, and well-being. A linear regression model was utilized to investigate factors associated with well-being, followed by a pathway analysis to assess the direct and indirect relationship between DHL and well-being. Results: The scores of DHL and overall well-being were 3.1 ± 0.4 and 74.4 ± 19.7, respectively. Social status (B = 2.40, 95% confidence interval (CI) 1.73-3.07, p < 0.001), DHL (B 0.29, 95% CI 0.10-0.49, p < 0.001), importance of online information searching (B = 0.78, 95% CI 0.38-1.17, p < 0.001), and information satisfaction (B = 3.59, 95% CI 2.22-4.94, p < 0.001) were positively associated with well-being, whereas higher fear of COVID-19 scores (B = -0.38, 95% CI -0.55-(-0.21), p < 0.001) and female (B = -2.99, 95% CI -5.02-0.6, p = 0.004) were associated with lower well-being, when compared with lower fear scores and male, respectively. Fear of COVID-19 (B = 0.03, 95% CI 0.016-0.04, p < 0.001), importance of online information searching (B = 0.03, 95% CI 0.01-0.05, p = 0.005), and information satisfaction (B = 0.05, 95% CI 0.023-0.067, p < 0.001) were significantly mediated the relationship between DHL and well-being. Conclusion: Higher DHL scores show direct and indirect associations with higher well-being scores. Fear, importance of online information searching, and information satisfaction significantly contributed to the association.
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Digital Health Literacy (DHL) helps online users with navigating the infodemic and co-existing conspiracy beliefs to avoid mental distress and maintain well-being. We aimed to investigate the association between DHL and future anxiety (FA); and examine the potential mediation roles of information satisfaction and fear of COVID-19 (F-CoV). A web-based cross-sectional survey was carried out among 1631 Taiwanese university students aged 18 years and above from June 2021 to March 2022. Data collected were socio-demographic characteristics (sex, age, social status, university location), information satisfaction, F-CoV, DHL and FA (using Future Dark scale). The linear regression model was used to explore factors associated with FA. The pathway analysis was further used to evaluate the direct and indirect relationship between DHL and FA. A higher score of DHL (B = -0.21; 95% CI, -0.37, -0.06; p = 0.006), and information satisfaction (B = -0.16; 95% CI, -0.24, -0.08; p < 0.001) were associated with a lower FA score, whereas a higher F-CoV score was associated with a higher FA score (B = 0.43; 95% CI, 0.36, 0.50; p < 0.001). DHL showed the direct impact (B = -0.1; 95% CI, -0.17, -0.04; p = 0.002) and indirect impact on FA as mediated by information satisfaction (B = -0.04; 95% CI, -0.06, -0.01; p = 0.002) and F-CoV (B = -0.06, 95% CI, -0.08, -0.04; p < 0.001). Strategic approaches to promote DHL, information satisfaction, lower F-CoV are suggested to reduce FA among students.
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COVID-19 , Alfabetización en Salud , Humanos , COVID-19/epidemiología , SARS-CoV-2 , Estudios Transversales , Encuestas y Cuestionarios , Ansiedad/epidemiologíaRESUMEN
BACKGROUND: School principals have been reported to have a higher prevalence of burnout and psychological problems than their colleagues. During the pandemic, extra workload and pressure from unprecedented situations potentially cause fear, stress and depression. Therefore, we aimed to explore associated factors of stress, fear of COVID-19 (F-CoV-19S) and depressive symptoms among school principals. METHODS: A cross-sectional online survey was conducted in Taiwan from 23 June to 16 July 2021. Data of 413 school principals were collected, including socio-demographic factors, COVID-19-related factors, work-related information, health status, sense of coherence (SoC), health literacy (HL), F-CoV-19S, stress and depression. Multiple linear and logistic regression models were utilized to explore associations. RESULTS: School principals with symptoms like COVID-19 (S-COVID-19-S), or with health-related activity limitations had a higher score of stress (B = 0.92; p = .039) (B = 1.52; p < .001) and a higher depression likelihood (OR = 3.38; p < .001) (OR = 3.06; p < .001), whereas those with a better SoC had a lower stress score (B = -1.39; p < .001) and a lower depression likelihood (OR = 0.76; p = .020). School principals confusing about COVID-19-related information had a higher score of stress (B = 2.47; p < .001) and fear (B = 3.77; p < .001). The longer working time was associated with a higher fear score (B = 1.69; p = .006). Additionally, school principals with a higher HL score had a lower stress score (B = -1.76; p < .001), a lower fear score (B = -1.85; p < .001) and a lower depression likelihood (OR = 0.53; p = .043). CONCLUSIONS: Health-related activity limitations, S-COVID-19-S, COVID-19-related information confusion and longer working hours were positively associated with at least one mental health problem (e.g. stress, fear and depression), whereas better SoC and HL showed the benefits to mitigate fear, stress and depressive symptoms in school principals. Our study provides evidence for appropriate strategies to improve principals' mental health during the pandemic.Key messages:School principals with health-related activity limitations or with symptoms like COVID-19 were more likely to be stressed and depressed.Higher levels of stress and fear were observed in school principals who confused about COVID-19-related information, and who had longer working time than before the pandemic.Better sense of coherence and higher health literacy could potentially mitigate the fear, stress and depressive symptoms in school principals.
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COVID-19 , Alfabetización en Salud , Sentido de Coherencia , Ansiedad/diagnóstico , COVID-19/epidemiología , Estudios Transversales , Depresión/diagnóstico , Miedo , Humanos , SARS-CoV-2 , Instituciones Académicas , Encuestas y CuestionariosRESUMEN
PURPOSES: To explore the associated factors of COVID-19 vaccine hesitancy and examine psychometric properties of the coronavirus-related health literacy questionnaire (HLS-COVID-Q22) and Oxford COVID-19 Vaccine Hesitancy questionnaire. METHODS: An online survey was conducted from 23 June to 16 July 2021 on 387 school principals across Taiwan. Data collection included socio-demographic characteristics, information related to work, physical and mental health, COVID-19 related perceptions, sense of coherence, coronavirus-related health literacy, and vaccine hesitancy. Principal component analysis, correlation analysis, linear regression models were used for validating HLS-COVID-Q22, Oxford COVID-19 Vaccine Hesitancy, and examining the associations. RESULTS: HLS-COVID-Q22 and Oxford COVID-19 Vaccine Hesitancy were found with satisfactory construct validity (items loaded on one component with factor loading values range 0.57 to 0.81, and 0.51 to 0.78), satisfactory convergent validity (item-scale correlations range 0.60 to 0.79, and 0.65 to 0.74), high internal consistency (Cronbach's alpha = 0.96 and 0.90), and without floor or ceiling effects (percentages of possibly lowest score and highest score <15%), respectively. Low scores of vaccine hesitancy were found in male principals (regression coefficient, B, -0.69; 95% confidence interval, 95%CI, -1.29, -0.10; p = 0.023), principals with better well-being (B, -0.25; 95%CI, -0.47, -0.03; p = 0.029), and higher HLS-COVID-Q22 (B, -1.22; 95%CI, -1.89, -0.54; p < 0.001). CONCLUSIONS: HLS-COVID-Q22 and Oxford COVID-19 Vaccine Hesitancy were valid and reliable tools. Male principals and those with better well-being, and higher health literacy had a lower level of vaccine hesitancy. Improving principals' health literacy and well-being is suggested to be a strategic approach to increase vaccine acceptance for themselves, their staff, and students.
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Protein post-translational modifications (PTMs) play a pivotal role in numerous biological processes by modulating regulation of protein function. We have developed iPTMnet (http://proteininformationresource.org/iPTMnet) for PTM knowledge discovery, employing an integrative bioinformatics approach-combining text mining, data mining, and ontological representation to capture rich PTM information, including PTM enzyme-substrate-site relationships, PTM-specific protein-protein interactions (PPIs) and PTM conservation across species. iPTMnet encompasses data from (i) our PTM-focused text mining tools, RLIMS-P and eFIP, which extract phosphorylation information from full-scale mining of PubMed abstracts and full-length articles; (ii) a set of curated databases with experimentally observed PTMs; and iii) Protein Ontology that organizes proteins and PTM proteoforms, enabling their representation, annotation and comparison within and across species. Presently covering eight major PTM types (phosphorylation, ubiquitination, acetylation, methylation, glycosylation, S-nitrosylation, sumoylation and myristoylation), iPTMnet knowledgebase contains more than 654 500 unique PTM sites in over 62 100 proteins, along with more than 1200 PTM enzymes and over 24 300 PTM enzyme-substrate-site relations. The website supports online search, browsing, retrieval and visual analysis for scientific queries. Several examples, including functional interpretation of phosphoproteomic data, demonstrate iPTMnet as a gateway for visual exploration and systematic analysis of PTM networks and conservation, thereby enabling PTM discovery and hypothesis generation.
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Bases de Datos de Proteínas , Bases del Conocimiento , Procesamiento Proteico-Postraduccional , Animales , Biología Computacional , Minería de Datos , Enzimas/metabolismo , Humanos , Internet , Fosforilación , Mapas de Interacción de Proteínas , Alineación de SecuenciaRESUMEN
Protein post-translational modification (PTM) is an essential cellular regulatory mechanism, and disruptions in PTM have been implicated in disease. PTMs are an active area of study in many fields, leading to a wealth of PTM information in the scientific literature. There is a need for user-friendly bioinformatics resources that capture PTM information from the literature and support analyses of PTMs and their functional consequences. This chapter describes the use of iPTMnet ( http://proteininformationresource.org/iPTMnet/ ), a resource that integrates PTM information from text mining, curated databases, and ontologies and provides visualization tools for exploring PTM networks, PTM crosstalk, and PTM conservation across species. We present several PTM-related queries and demonstrate how they can be addressed using iPTMnet.
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Biología Computacional/métodos , Bases de Datos de Proteínas , Procesamiento Proteico-Postraduccional , Programas Informáticos , Navegador Web , Animales , Minería de Datos/métodos , Humanos , Ratones , Fosfotransferasas , Proteínas de Plantas , Unión Proteica , Mapeo de Interacción de Proteínas/métodos , Mapas de Interacción de Proteínas , Ratas , Motor de Búsqueda , Interfaz Usuario-ComputadorRESUMEN
The Protein Ontology (PRO; http://purl.obolibrary.org/obo/pr) formally defines and describes taxon-specific and taxon-neutral protein-related entities in three major areas: proteins related by evolution; proteins produced from a given gene; and protein-containing complexes. PRO thus serves as a tool for referencing protein entities at any level of specificity. To enhance this ability, and to facilitate the comparison of such entities described in different resources, we developed a standardized representation of proteoforms using UniProtKB as a sequence reference and PSI-MOD as a post-translational modification reference. We illustrate its use in facilitating an alignment between PRO and Reactome protein entities. We also address issues of scalability, describing our first steps into the use of text mining to identify protein-related entities, the large-scale import of proteoform information from expert curated resources, and our ability to dynamically generate PRO terms. Web views for individual terms are now more informative about closely-related terms, including for example an interactive multiple sequence alignment. Finally, we describe recent improvement in semantic utility, with PRO now represented in OWL and as a SPARQL endpoint. These developments will further support the anticipated growth of PRO and facilitate discoverability of and allow aggregation of data relating to protein entities.
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Biología Computacional/métodos , Bases de Datos Genéticas , Proteínas , Animales , Humanos , Proteínas/química , Proteínas/genética , Navegador WebRESUMEN
Despite increasing application of the pre-grafting expansion during autologous fat transplantation in breast reconstruction, little is known about its mechanism of action. To address that, ventral skins of miniature pigs were treated over a 10-day or 21-day period, with continuous suction at -50 mm Hg via a 7-cm diameter rubber-lined suction-cup device. Soft tissue thickness increased immediately after this external volume expansion (EVE) treatment, such increase completely disappeared by the next day. In the dermis and subcutaneous fat, the EVE treated groups showed significant increases in blood vessel density evident by CD31 staining as well as in vascular networks layered with smooth muscle cells when compared with the control group. This finding was corroborated by the increased percentage of endothelial cells present in the treatment groups. There was no significant difference in the percentages of proliferating basal keratinocytes or adipocytes, nor in epidermal thickness. Moreover, the EVE had no effect on proliferation or differentiation potential of adipose stem cells. Taken together, the major effects of EVE appeared to be vascular remodeling and maturation of functional blood vessels. This understanding may help clinicians optimize the vascularity of the recipient bed to further improve fat graft survival.
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Adipocitos/citología , Tejido Adiposo/irrigación sanguínea , Piel/irrigación sanguínea , Expansión de Tejido/instrumentación , Adipocitos/metabolismo , Tejido Adiposo/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Dermis/irrigación sanguínea , Dermis/metabolismo , Modelos Animales , Miocitos del Músculo Liso/metabolismo , Neovascularización Fisiológica , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Piel/citología , Piel/metabolismo , Succión , Porcinos , Porcinos Enanos , Expansión de Tejido/métodosRESUMEN
The Protein Ontology (PRO) defines protein classes and their interrelationships from the family to the protein form (proteoform) level within and across species. One of the unique contributions of PRO is its representation of post-translationally modified (PTM) proteoforms. However, progress in adding PTM proteoform classes to PRO has been relatively slow due to the extensive manual curation effort required. Here we report an automated pipeline for creation of PTM proteoform classes that leverages two phosphorylation-focused text mining tools (RLIMS-P, which detects mentions of kinases, substrates, and phosphorylation sites, and eFIP, which detects phosphorylation-dependent protein-protein interactions (PPIs)) and our integrated PTM database, iPTMnet. By applying this pipeline, we obtained a set of ~820 substrate-site pairs that are suitable for automated PRO term generation with literature-based evidence attribution. Inclusion of these terms in PRO will increase PRO coverage of species-specific PTM proteoforms by 50%. Many of these new proteoforms also have associated kinase and/or PPI information. Finally, we show a phosphorylation network for the human and mouse peptidyl-prolyl cis-trans isomerase (PIN1/Pin1) derived from our dataset that demonstrates the biological complexity of the information we have extracted. Our approach addresses scalability in PRO curation and will be further expanded to advance PRO representation of phosphorylated proteoforms.
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One new acetogenin, 6-hydroxy-8-pentadecyloxocane-2,7-dione ( 1), and four new prenylated flavonoids, 4''a,5'',6'',7'',8'',8''a-hexahydro-5,3',4'-trihydroxy-5'',5'',8''a-trimethyl-4 H-chromeno[2'',3'':7,6]flavone ( 2), 4''a,5'',6'',7'',8'',8''a-hexahydro-5,3',4',-trihydroxy-5'',5'',8''a-trimethyl-4 H-chromeno[2'',3'':7,8]flavone ( 3), 2-(3,4-dihydroxyphenyl)-6-((2,2-dimethyl-6-methylenecyclohexyl)methyl)-5,7-dihydroxy-chroman-4-one ( 4), and 2-(3,4-dihydroxy-2-[(2,6,6-trimethylcyclohex-2-enyl)methyl]phenyl)-3,5,7-trihydroxy-4 H-chromen-4-one ( 5), together with six known compounds, were isolated and purified from the rhizomes of Helminthostachys zeylanica by column chromatography and high performance liquid chromatography (HPLC) via bioactivity-guided fractionation isolation. The structures of the new isolates were elucidated by spectroscopic methods. Compounds 1, 3, and 5 showed inhibitory activities on either superoxide anion generation or elastase release by human neutrophils in response to formyl-L-methionyl-L-leucyl-L-phenylalanine/cytochalasin B (FMLP/CB).
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Acetogeninas/química , Helechos/química , Flavonoides/química , Neutrófilos/efectos de los fármacos , Elastasa Pancreática/metabolismo , Superóxidos/metabolismo , Acetogeninas/aislamiento & purificación , Acetogeninas/toxicidad , Adolescente , Adulto , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Antiinflamatorios/toxicidad , Línea Celular Tumoral , Flavonoides/aislamiento & purificación , Flavonoides/toxicidad , Humanos , Neutrófilos/enzimología , Elastasa Pancreática/antagonistas & inhibidores , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Extractos Vegetales/toxicidad , Prenilación , Rizoma/química , Superóxidos/antagonistas & inhibidores , Adulto JovenRESUMEN
Eight new prenylated flavonoids, ugonins M-T (1-8), together with five known compounds, ugonins J-L (9-11), 5,4'-dihydroxy-4'',4''-dimethyl-5''-methyl-5''H-dihydrofurano[2'',3'':6,7]flavanone, and quercetin, were isolated and purified from the rhizomes of Helminthostachys zeylanica. The structures of the new isolates were elucidated by spectroscopic and chemical methods. Compounds 1, 3, 5, 7, 8, and 11 showed inhibition of superoxide anion generation and elastase release by human neutrophils in response to formyl-l-methionyl-l-leucyl-l-phenylalanine/cytochalasin B (FMLP/CB).
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Antiinflamatorios no Esteroideos/aislamiento & purificación , Antiinflamatorios no Esteroideos/farmacología , Flavonoides/aislamiento & purificación , Flavonoides/farmacología , Neutrófilos/efectos de los fármacos , Antiinflamatorios no Esteroideos/química , Citocalasina B/farmacología , Helechos/química , Flavonoides/química , Humanos , Estructura Molecular , N-Formilmetionina Leucil-Fenilalanina/farmacología , Rizoma/química , TaiwánRESUMEN
Ceramide accumulation in neurons during various disorders is associated with acute and chronic neurodegeneration. Here we investigate the neuroprotective effects of furopyrazole derivative of benzylindazole analogs on C2 ceramide-induced cell death in primary cortical neurons. Among the 12 furopyrazole derivative of benzylindazole analogs tested, carbinol derivatives exhibited strongest neuroprotection against C2 ceramide-induced apoptosis. The results suggest that furopyrazole derivative of benzylindazole analogs can be developed as useful neuroprotectants against neurodegenerative diseases.
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Apoptosis/efectos de los fármacos , Indazoles/farmacología , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/química , Pirazoles/farmacología , Esfingosina/análogos & derivados , Animales , Células Cultivadas , Corteza Cerebral , Inhibidores Enzimáticos , Humanos , Indazoles/química , Enfermedades Neurodegenerativas/tratamiento farmacológico , Neuronas/patología , Fármacos Neuroprotectores/farmacología , Pirazoles/química , Esfingosina/farmacología , Relación Estructura-ActividadRESUMEN
Oxidative stress plays an important role in the pathological processes of various neurodegenerative diseases. Ugonin K, a flavonoid isolated from the rhizomes of Helminthostachys zeylanica, possesses potent antioxidant property. In this study, we investigate the neuroprotective effects of ugonin K on hydrogen peroxide (H(2)O(2))-induced apoptosis in SH-SY5Y cells. Incubation of SH-SY5Y cells with H(2)O(2) for 24 h induced cell death measured with MTT assay. Hoechst 33258 staining confirmed that the reduced cell viability by H(2)O(2) was due to apoptosis. In addition, H(2)O(2) increased the expression of 17-kDa cleaved fragment of caspase-3 which could be reversed by pretreatment with ugonin K. Pretreatment with ugonin K attenuated H(2)O(2)-induced cell death in a dose-dependent manner. Neuroprotective effect of ugonin K was abolished by ERK and PI3K inhibitors. Pretreatment with JNK kinase and p38 MAPK inhibitors had no effect on ugonin K-mediated protection against H(2)O(2)-induced apoptosis. Western blotting with anti-phospho-ERK1/2 and anti-phospho-Akt (pS473) antibodies showed that ugonin K increased both ERK1/2 and Akt phosphorylation. These results suggest that ugonin K by activation of ERK1/2 and PI3K/Akt signal pathways protects SH-SY5Y cells from H(2)O(2)-induced apoptosis.
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Apoptosis/efectos de los fármacos , Citotoxinas/farmacología , Medicamentos Herbarios Chinos/farmacología , Flavonoides/farmacología , Peróxido de Hidrógeno/farmacología , Fármacos Neuroprotectores/farmacología , Caspasa 3/metabolismo , Línea Celular Tumoral , Activación Enzimática , Humanos , Proteína Quinasa 1 Activada por Mitógenos/fisiología , Proteína Quinasa 3 Activada por Mitógenos/fisiología , Proteína Quinasa 8 Activada por Mitógenos/fisiología , Proteína Quinasa 9 Activada por Mitógenos/fisiología , Neuroblastoma , Fosfatidilinositol 3-Quinasas/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismoRESUMEN
Abruquinone A, a natural isoflavanquinone, suppressed A23187- and formyl-Met-Leu-Phe (fMLP)-induced production of thromboxane B(2) and leukotriene B(4) from rat neutrophils. This compound failed to inhibit the enzymatic activity of ram seminal vesicles cyclooxygenase (COX) and human recombinant 5-lipoxygenase (5-LO) in cell-free systems. Abruquinone A diminished the arachidonic acid release from [(3)H]arachidonic acid-loaded neutrophils stimulated with either fMLP or A23187, whereas it had no inhibitory effect on the cytosolic phospholipase A(2) (cPLA(2)) activity of neutrophil cytosolic fraction. Based on the Western blot analysis, the nuclear membrane recruitment of cPLA(2) and 5-LO was inhibited by abruquinone A in A23187- as well as in fMLP-stimulated cells. Moreover, the phosphorylation of both cPLA(2) and extracellular signal regulated kinases (ERKs) induced by fMLP and A23187 was attenuated by abruquinone A in a parallel concentration-dependent manner. Abruquinone A attenuated both fMLP- and ionomycin-mediated [Ca(2+)](i) elevation in a concentration range that inhibited the recruitment of cPLA(2) to nuclear membrane. These results indicate that the blockade of leukotriene B(4) production by abruquinone A implicates the attenuation of 5-LO membrane translocation. Inhibition of thromboxane B(2) production by abruquinone A is due to the attenuation of cPLA(2) membrane recruitment and/or cPLA(2) phosphorylation through the blockade of [Ca(2+)](i) elevation and ERK activation, respectively.
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Antiinflamatorios no Esteroideos/farmacología , Benzopiranos/farmacología , Benzoquinonas/farmacología , Citosol/enzimología , Inhibidores de la Lipooxigenasa , Neutrófilos/enzimología , Inhibidores de Fosfolipasa A2 , Animales , Araquidonato 5-Lipooxigenasa/metabolismo , Ácidos Araquidónicos/metabolismo , Western Blotting , Calcimicina/antagonistas & inhibidores , Calcimicina/farmacología , Calcio/metabolismo , Ciclooxigenasa 2/metabolismo , Citosol/efectos de los fármacos , Eicosanoides/metabolismo , Quinasas MAP Reguladas por Señal Extracelular/antagonistas & inhibidores , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Leucotrieno B4/biosíntesis , Masculino , N-Formilmetionina Leucil-Fenilalanina/antagonistas & inhibidores , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Fosfolipasas A2/metabolismo , Ratas , Ratas Sprague-Dawley , Tromboxano B2/biosíntesisRESUMEN
A nonradioactive, sensitive, rapid, and specific method for the determination of methionine adenosyltransferase activity has been established. In this method, the methyl group of S-adenosyl-L-methionine was enzymatically transferred to esculetin with the aid of catechol-O-methyltransferase and then the resulting scopoletin was extracted with n-hexane:ethyl acetate (7:3, v/v) and measured by high-performance liquid chromatography with Si 60 column and fluorometric detection with excitation and emission wavelengths at 347 and 415 nm, respectively. The detection limit for scopoletin was about 100 fmol. Using this method to determine MAT activity in HL-60 cells required only about 2.5 microg of protein and the incubation time needed for enzymatic reaction is less than 30 min. The HPLC analysis procedure took only 5 min per sample. The kinetic study showed that MAT in HL-60 cells exhibited negative cooperativity with a Hill coefficient of 0.5. The values of K(m) and V(max) were 6.1+/-0.3 microM and 135.4+/-1.5 nmol AdoMet formed/mg protein/h, respectively.
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Catecol O-Metiltransferasa/metabolismo , Fluorometría/métodos , Metionina Adenosiltransferasa/análisis , Metionina Adenosiltransferasa/metabolismo , Calibración , Cromatografía Líquida de Alta Presión , Células HL-60 , Humanos , Cinética , Mitoguazona/farmacología , Estructura Molecular , Reproducibilidad de los Resultados , S-Adenosilmetionina/metabolismo , Escopoletina/metabolismo , Sensibilidad y Especificidad , Espectrometría de FluorescenciaRESUMEN
In this study, the cellular localization of the inhibitory effect of a natural flavonoid cirsimaritin against formyl-methionyl-leucyl-phenylalanine (fMLP)-induced respiratory burst in rat neutrophils was investigated. Cirsimaritin concentration-dependently inhibited the superoxide anion (O(*-)(2))generation and O(2) consumption (IC(50) 11.5+/-2.2 micro M and 17.0+/-3.9 micro M, respectively) of neutrophils. Cirsimaritin did not reduce, but slightly enhanced the O(*-)(2) generation in phorbol 12-myristate 13-acetate (PMA)-activated or arachidonic acid-stimulated NADPH oxidase preparation as well as during the autoxidation of dihydroxyfumaric acid. Cirsimaritin did not elevate cellular cAMP levels, and only partially inhibited the fMLP-induced [Ca(2+)](i) changes in the presence or absence of extracellular Ca(2+). The phosphorylation of protein tyrosine, extracellular signal-regulated protein kinase and Akt caused by fMLP were attenuated by cirsimaritin in a concentration-dependent manner. In contrast, cirsimaritin had no effect on the phosphorylation of p38 mitogen-activated protein kinase. Cirsimaritin produced a concentration-dependent reduction in the formation of phosphatidic acid and phosphatidylethanol, in the presence of ethanol, from fMLP-stimulated neutrophils (IC(50) 15.1+/-6.5 micro M and 15.6+/-3.4 micro M, respectively), but did not affect the phosphatidylethanol formation in response to PMA. Under the similar concentration range, cirsimaritin attenuated the membrane translocation of ARF and Rho A. However, the GTPgammaS-stimulated membrane-associated ARF and Rho in cell lysate were unaffected by cirsimaritin. Collectively, these results indicate that the inhibition of fMLP-induced respiratory burst by cirsimaritin in rat neutrophils is likely mainly through the blockade of phospholipase D signaling pathway.
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Flavonas , Flavonoides/farmacología , N-Formilmetionina Leucil-Fenilalanina/antagonistas & inhibidores , Neutrófilos/efectos de los fármacos , Fosfolipasa D/antagonistas & inhibidores , Estallido Respiratorio/efectos de los fármacos , Animales , Relación Dosis-Respuesta a Droga , Activación Enzimática/efectos de los fármacos , Activación Enzimática/fisiología , Inhibidores Enzimáticos/farmacología , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/enzimología , Fosfolipasa D/fisiología , Ratas , Estallido Respiratorio/fisiología , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
A simple and sensitive fluorometric method for the determination of nalidixic acid was established by using 0.75M sodium borohydride and 7.5% hydrogen peroxide solution as fluorogenic reagents. Analyte concentrations of 0.0232-11.6 pg/mL could be determined with high precision and accuracy by the method. A relative standard deviation of 1.75% was obtained for a nalidixic acid concentration of 0.232 pg/mL. The method was satisfactorily applied to the determination of nalidixic acid in human serum, fish muscle, and chicken muscle, and the calibration curves were linear from 0.23 to 58.00 pg/mL, from 9.28 to 32.48 mg/kg, and from 4.64 to 23.20 mg/kg, respectively. The specificity of the reaction is also discussed.