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Prostaglandin E2 is produced in response to inflammation, often associated with human disease. As prostaglandins are rapidly metabolized, quantification of end urinary metabolites depend on chemical synthesis of isotopically labeled standards to support metabolite quantification. A concise synthesis of tetranor-PGE1 is described including a late stage incorporation of an isotopically labeled side-chain.
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Background: Acute kidney injury independently predicts mortality in falciparum malaria. It is unknown whether acetaminophen's capacity to inhibit plasma hemoglobin-mediated oxidation is renoprotective in severe malaria. Methods: This phase 2, open-label, randomized controlled trial conducted at two hospitals in Bangladesh assessed effects on renal function, safety, pharmacokinetic (PK) properties and pharmacodynamic (PD) effects of acetaminophen. Febrile patients (>12 years) with severe falciparum malaria were randomly assigned to receive acetaminophen (1 g 6-hourly for 72 hours) or no acetaminophen, in addition to intravenous artesunate. Primary outcome was the proportional change in creatinine after 72 hours stratified by median plasma hemoglobin. Results: Between 2012 and 2014, 62 patients were randomly assigned to receive acetaminophen (n = 31) or no acetaminophen (n = 31). Median (interquartile range) reduction in creatinine after 72 hours was 23% (37% to 18%) in patients assigned to acetaminophen, versus 14% (29% to 0%) in patients assigned to no acetaminophen (P = .043). This difference in reduction was 37% (48% to 22%) versus 14% (30% to -71%) in patients with hemoglobin ≥45000 ng/mL (P = .010). The proportion with progressing kidney injury was higher among controls (subdistribution hazard ratio, 3.0; 95% confidence interval, 1.1 to 8.5; P = .034). PK-PD analyses showed that higher exposure to acetaminophen increased the probability of creatinine improvement. No patient fulfilled Hy's law for hepatotoxicity. Conclusions: In this proof-of-principle study, acetaminophen showed renoprotection without evidence of safety concerns in patients with severe falciparum malaria, particularly in those with prominent intravascular hemolysis. Clinical Trials Registration: NCT01641289.
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Acetaminofen/uso terapêutico , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/prevenção & controle , Artesunato/efeitos adversos , Artesunato/uso terapêutico , Malária Falciparum/tratamento farmacológico , Acetaminofen/administração & dosagem , Acetaminofen/farmacocinética , Adolescente , Adulto , Analgésicos não Narcóticos/administração & dosagem , Analgésicos não Narcóticos/farmacocinética , Analgésicos não Narcóticos/uso terapêutico , Antimaláricos/efeitos adversos , Antimaláricos/uso terapêutico , Área Sob a Curva , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: Triamterene, because of its potassium-sparing properties, is frequently used in combination with hydrochlorothiazide (HCTZ) to treat patients with hypertension. By inhibiting the epithelial sodium channel (ENaC) in the cortical collecting duct, triamterene reduces potassium secretion, thus reducing the risk of hypokalemia. Whether triamterene has an independent effect on blood pressure (BP) has not been well studied. OBJECTIVE: To determine if triamterene provides an effect to further lower BP in patients treated with HCTZ. DESIGN: We conducted an observational study using electronic medical record data from the Indiana Network for Patient Care. Participants were 17,291 patients with the diagnosis of hypertension between 2004 and 2012. MAIN MEASURES: BP was the primary outcome. We compared the BP between patients who were taking HCTZ, with and without triamterene, either alone or in combination with other antihypertensive medications, by using a propensity score analysis. For each medication combination, we estimated the propensity score (i.e., probability) of a patient receiving triamterene using a logistic regression model. Patients with similar propensity scores were stratified into subclasses and BP was compared between those taking triamterene or not within each subclass; the effect of triamterene was then assessed by combining BP differences estimated from all subclasses. KEY RESULTS: The mean systolic BP in the triamterene + HCTZ group was 3.8 mmHg lower than in the HCTZ only group (p < 0.0001); systolic BP was similarly lower for patients taking triamterene with other medication combinations. Systolic BP reduction was consistently observed for different medication combinations. The range of systolic BP reduction was between 1 and 4 mm Hg, depending on the concurrently used medications. CONCLUSIONS: In the present study, triamterene was found to enhance the effect of HCTZ to lower BP. In addition to its potassium-sparing action, triamterene's ability to lower BP should also be considered.
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Pressão Sanguínea/efeitos dos fármacos , Hidroclorotiazida/administração & dosagem , Hipertensão/tratamento farmacológico , Triantereno/administração & dosagem , Diuréticos/administração & dosagem , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Seguimentos , Humanos , Hipertensão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The thromboxane synthase converts prostaglandin H(2) to thromboxane A(2) and malondialdehyde (MDA) in approximately equimolar amounts. A reactive dicarbonyl, MDA forms covalent adducts of amino groups, including the ε-amine of lysine, but the importance of this reaction in platelets was unknown. Utilizing a novel LC/MS/MS method for analysis of one of the MDA adducts, the dilysyl-MDA cross-link, we demonstrated that dilysyl-MDA cross-links in human platelets are formed following platelet activation via the cyclooxygenase (COX)-1/thromboxane synthase pathway. Salicylamine and analogs of salicylamine were shown to react with MDA preferentially, thereby preventing formation of lysine adducts. Dilysyl-MDA cross-links were measured in two diseases known to be associated with increased platelet activation. Levels of platelet dilysyl-MDA cross-links were increased by 2-fold in metabolic syndrome relative to healthy subjects, and by 1.9-fold in sickle cell disease (SCD). In patients with SCD, the reduction of platelet dilysyl-MDA cross-links following administration of nonsteroidal anti-inflammatory drug provided evidence that MDA modifications of platelet proteins in this disease are derived from the COX pathway. In summary, MDA adducts of platelet proteins that cross-link lysines are formed on platelet activation and are increased in diseases associated with platelet activation. These protein modifications can be prevented by salicylamine-related scavengers.
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Ácidos Aminossalicílicos/farmacologia , Malondialdeído/sangue , Adulto , Idoso , Anemia Falciforme/sangue , Plaquetas/efeitos dos fármacos , Plaquetas/metabolismo , Proteínas Sanguíneas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Humanos , Síndrome Metabólica/sangue , Pessoa de Meia-Idade , Ativação PlaquetáriaRESUMO
OBJECTIVES: This trial evaluated the efficacy of acetaminophen in reducing oxidative injury, as measured by plasma F2-isoprostanes, in adult patients with severe sepsis and detectable plasma cell-free hemoglobin. DESIGN: Single-center, randomized, double-blind, placebo-controlled phase II trial. SETTING: Medical ICU in a tertiary, academic medical center. PATIENTS: Critically ill patients 18 years old or older with severe sepsis and detectable plasma cell-free hemoglobin. INTERVENTIONS: Patients were randomized 1:1 to enteral acetaminophen 1 g every 6 hours for 3 days (n = 18) or placebo (n = 22) with the same dosing schedule and duration. MEASUREMENTS AND MAIN RESULTS: F2-Isoprostanes on study day 3, the primary outcome, did not differ between acetaminophen (30 pg/mL; interquartile range, 24-41) and placebo (36 pg/mL; interquartile range, 25-80; p = 0.35). However, F2-isoprostanes were significantly reduced on study day 2 in the acetaminophen group (24 pg/mL; interquartile range, 19-36) when compared with placebo (36 pg/mL; interquartile range, 23-55; p = 0.047). Creatinine on study day 3, a secondary outcome, was significantly lower in the acetaminophen group (1.0 mg/dL; interquartile range, 0.6-1.4) when compared with that in the placebo (1.3 mg/dL; interquartile range, 0.83-2.0; p = 0.039). There was no statistically significant difference in hospital mortality (acetaminophen 5.6% vs placebo 18.2%; p = 0.355) or adverse events (aspartate aminotransferase or alanine aminotransferase > 400; acetaminophen 9.5% vs placebo 4.3%; p = 0.599). CONCLUSIONS: In adults with severe sepsis and detectable plasma cell-free hemoglobin, treatment with acetaminophen within 24 hours of ICU admission may reduce oxidative injury and improve renal function. Additional study is needed to confirm these findings and determine the effect of acetaminophen on patient-centered outcomes.
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Acetaminofen/uso terapêutico , Analgésicos não Narcóticos/uso terapêutico , F2-Isoprostanos/sangue , Oxirredução/efeitos dos fármacos , Sepse/tratamento farmacológico , Acetaminofen/administração & dosagem , Acetaminofen/efeitos adversos , Adulto , Analgésicos não Narcóticos/efeitos adversos , Sistema Livre de Células , Creatinina/sangue , Estado Terminal , Método Duplo-Cego , Feminino , Hemoglobinas/análise , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Propofol/administração & dosagem , Respiração Artificial , Sepse/mortalidade , Sepse/fisiopatologiaRESUMO
Inflammation and subsequent cyclooxygenase-2 (COX-2) activity has long been linked with the development of cancer, although little is known about any epigenetic effects of COX-2. A product of COX-2 activation, levuglandin (LG) quickly forms covalent bonds with nearby primary amines, such as those in lysine, which leads to LG-protein adducts. Here, we demonstrate that COX-2 activity causes LG-histone adducts in cultured cells and liver tissue, detectable through LC-MS, with the highest incidence in histone H4. Adduction is blocked by a γ-ketoaldehyde scavenger, which has no effect on COX-2 activity as measured by PGE2 production. Formation of the LG-histone adduct is associated with an increased histone solubility in NaCl, indicating destabilization of the nucleosome structure; this is also reversed with scavenger treatment. These data demonstrate that COX-2 activity can cause histone adduction and loosening of the nucleosome complex, which could lead to altered transcription and contribute to carcinogenesis.
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Ciclo-Oxigenase 2/química , DNA/química , Histonas/química , Prostaglandina D2/análogos & derivados , Prostaglandinas E/química , Cromatografia Líquida , Espectrometria de Massas , Prostaglandina D2/química , SolubilidadeRESUMO
Base propenals are products of the reaction of DNA with oxidants such as peroxynitrite and bleomycin. The most reactive base propenal, adenine propenal, is mutagenic in Escherichia coli and reacts with DNA to form covalent adducts; however, the reaction of adenine propenal with protein has not yet been investigated. A survey of the reaction of adenine propenal with amino acids revealed that lysine and cysteine form adducts, whereas histidine and arginine do not. N(ε)-Oxopropenyllysine, a lysine-lysine cross-link, and S-oxopropenyl cysteine are the major products. Comprehensive profiling of the reaction of adenine propenal with human serum albumin and the DNA repair protein, XPA, revealed that the only stable adduct is N(ε)-oxopropenyllysine. The most reactive sites for modification in human albumin are K190 and K351. Three sites of modification of XPA are in the DNA-binding domain, and two sites are subject to regulatory acetylation. Modification by adenine propenal dramatically reduces XPA's ability to bind to a DNA substrate.
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Adenina/análogos & derivados , Albumina Sérica/química , Proteína de Xeroderma Pigmentoso Grupo A/química , Adenina/química , Sequência de Aminoácidos , Cromatografia Líquida de Alta Pressão , Cisteína/química , Polarização de Fluorescência , Humanos , Lisina/química , Dados de Sequência Molecular , Peptídeos/análise , Peptídeos/química , Espectrometria de Massas em TandemRESUMO
BACKGROUND: The quality of the parent-child relationship has an important effect on a wide range of child outcomes. The evaluation of interventions to promote healthy parenting and family relationships is dependent on outcome measures which can quantify the quality of parent-child relationships. Between the Mothers' Object Relations - Short Form (MORS-SF) scale for babies and the Child-parent Relationship Scale (C-PRS) there is an age gap where no validated scales are available. We report the development and testing of an adaptation of the MORS-SF; the MORS (Child) scale and its use in children from the age of 2 years to 4 years. This scale aims to capture the nature of the parent-child relationship in a form which is short enough to be used in population surveys and intervention evaluations. METHODS: Construct and criterion validity, item salience and internal consistency were assessed in a sample of 166 parents of children aged 2-4 years old and compared with that of the C-PRS. The performance of the MORS (Child) as part of a composite measure with the HOME inventory was compared with that of the C-PRS using data collected in a randomised controlled trial and the national evaluation of Sure Start. RESULTS: MORS (Child) performed well in children aged 2-4 with high construct and criterion validity, item salience and internal consistency. One item in the C-PRS failed to load on either subscale and parents found this scale slightly more difficult to complete than the MORS (Child). The two measures performed very similarly in a factor analysis with the HOME inventory producing almost identical loadings. CONCLUSIONS: Adapting the MORS-SF for children aged 2-4 years old produces a scale to assess parent-child relationships that is easy to use and outperforms the more commonly used C-PRS in several respects.
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Relações Mãe-Filho , Pré-Escolar , Feminino , Humanos , Masculino , Relações Pais-Filho , Pais/psicologia , Reprodutibilidade dos Testes , Inquéritos e Questionários/normasRESUMO
Hemoproteins, hemoglobin and myoglobin, once released from cells can cause severe oxidative damage as a consequence of heme redox cycling between ferric and ferryl states that generates radical species that induce lipid peroxidation. We demonstrate in vitro that acetaminophen inhibits hemoprotein-induced lipid peroxidation by reducing ferryl heme to its ferric state and quenching globin radicals. Severe muscle injury (rhabdomyolysis) is accompanied by the release of myoglobin that becomes deposited in the kidney, causing renal injury. We previously showed in a rat model of rhabdomyolysis that redox cycling between ferric and ferryl myoglobin yields radical species that cause severe oxidative damage to the kidney. In this model, acetaminophen at therapeutic plasma concentrations significantly decreased oxidant injury in the kidney, improved renal function, and reduced renal damage. These findings also provide a hypothesis for potential therapeutic applications for acetaminophen in diseases involving hemoprotein-mediated oxidative injury.
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Acetaminofen/farmacologia , Hemeproteínas/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Insuficiência Renal/prevenção & controle , Rabdomiólise/complicações , Animais , Ácidos Araquidônicos/química , Ácidos Araquidônicos/metabolismo , Catálise/efeitos dos fármacos , Relação Dose-Resposta a Droga , Hemeproteínas/química , Hemoglobinas/química , Hemoglobinas/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Concentração de Íons de Hidrogênio , Ferro/química , Ferro/metabolismo , Masculino , Mioglobina/química , Mioglobina/metabolismo , Oxirredução/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Insuficiência Renal/etiologia , Insuficiência Renal/patologia , Rabdomiólise/metabolismo , EspectrofotometriaRESUMO
The critically endangered western gorillas (Gorilla gorilla) are divided into two subspecies: the western lowland (G. g. gorilla) and the Cross River (G. g. diehli) gorilla. Given the difficulty in sampling wild great ape populations and the small estimated size of the Cross River gorilla population, only one whole genome of a Cross River gorilla has been sequenced to date, hindering the study of this subspecies at the population level. In this study, we expand the number of whole genomes available for wild western gorillas, generating 41 new genomes (25 belonging to Cross River gorillas) using single shed hairs collected from gorilla nests. By combining these genomes with publicly available wild gorilla genomes, we confirm that Cross River gorillas form three population clusters. We also found little variation in genome-wide heterozygosity among them. Our analyses reveal long runs of homozygosity (>10 Mb), indicating recent inbreeding in Cross River gorillas. This is similar to that seen in mountain gorillas but with a much more recent bottleneck. We also detect past gene flow between two Cross River sites, Afi Mountain Wildlife Sanctuary and the Mbe Mountains. Furthermore, we observe past allele sharing between Cross River gorillas and the northern western lowland gorilla sites, as well as with the eastern gorilla species. This is the first study using single shed hairs from a wild species for whole genome sequencing to date. Taken together, our results highlight the importance of implementing conservation measures to increase connectivity among Cross River gorilla sites.
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Gorilla gorilla , Hominidae , Animais , Humanos , Gorilla gorilla/genética , Endogamia , Hominidae/genética , Genoma/genética , Fluxo GênicoRESUMO
Cytochrome (cyt) c can uncouple from the respiratory chain following mitochondrial stress and catalyze lipid peroxidation. Accumulating evidence shows that this phenomenon impairs mitochondrial respiratory function and also initiates the apoptotic cascade. Therefore, under certain conditions a pharmacological approach that can inhibit cyt c catalyzed lipid peroxidation may be beneficial. We recently showed that acetaminophen (ApAP) at normal pharmacologic concentrations can prevent hemoprotein-catalyzed lipid peroxidation in vitro and in vivo by reducing ferryl heme to its ferric state. We report here, for the first time, that ApAP inhibits cytochrome c-catalyzed oxidation of unsaturated free fatty acids and also the mitochondrial phospholipid, cardiolipin. Using isolated mitochondria, we also showed that ApAP inhibits cardiolipin oxidation induced by the pro-apoptotic protein, tBid. We found that the IC(50) of the inhibition of cardiolipin oxidation by ApAP is similar in both intact isolated mitochondria and cardiolipin liposomes, suggesting that ApAP penetrates well into the mitochondria. Together with our previous results, the findings presented herein suggest that ApAP is a pleiotropic inhibitor of peroxidase catalyzed lipid peroxidation. Our study also provides a potentially novel pharmacological approach for inhibiting the cascade of events that can result from redox cycling of cyt c.
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Acetaminofen/farmacologia , Analgésicos não Narcóticos/farmacologia , Citocromos c/metabolismo , Ácidos Graxos Insaturados/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Ácido Araquidônico/metabolismo , Cardiolipinas/metabolismo , Catálise , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Oxirredução/efeitos dos fármacosRESUMO
OBJECTIVE: The rate-limiting step in the biosynthesis of thromboxane A(2) (TxA(2)) and 12-hydroxyeicosatetraenoic acid (12-HETE) by platelets is activation of cytosolic phospholipase A(2α) (cPLA(2α)), which releases arachidonic acid, which is the substrate for cyclooxygenase-1 (COX-1) and 12-lipoxygenase. We evaluated signaling via the human platelet thrombin receptors, protease-activated receptor (PAR) 1 and PAR4, to the activation of cPLA(2α), which provides a substrate for the biosynthesis of TxA(2) and 12-HETE. METHODS AND RESULTS: Stimulating washed human platelets resulted in delayed biosynthesis of 12-HETE, which continues after maximal formation of TxA(2) is completed, suggesting that 12-HETE is not formed by the same pool of arachidonic acid that provides a substrate to COX-1. PAR1-induced formation of TxA(2) was inhibited by the phosphatidylinositol kinase inhibitor LY294002, whereas this inhibitor did not block 12-HETE biosynthesis. Both 1-butanol and propranolol also blocked TxA(2) biosynthesis but did not inhibit 12-HETE formation. CONCLUSIONS: The concerted evidence indicates that the platelet thrombin receptors signal activation of cPLA(2α) coupled to COX-1 by a pathway different from that signaling activation of the cPLA(2α) coupled to 12-lipoxygenase.
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Araquidonato 12-Lipoxigenase/metabolismo , Plaquetas/metabolismo , Ciclo-Oxigenase 1/metabolismo , Citosol/metabolismo , Fosfolipases A2 do Grupo IV/metabolismo , Receptores Ativados por Proteinase/metabolismo , Transdução de Sinais/fisiologia , 1-Butanol/farmacologia , Ácido 12-Hidroxi-5,8,10,14-Eicosatetraenoico/metabolismo , Ácido Araquidônico/metabolismo , Plaquetas/citologia , Plaquetas/efeitos dos fármacos , Cálcio/metabolismo , Cromonas/farmacologia , Eicosanoides/metabolismo , Inibidores Enzimáticos/farmacologia , Humanos , Técnicas In Vitro , Morfolinas/farmacologia , Propranolol/farmacologia , Proteína Quinase C/metabolismo , Tromboxano A2/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
INTRODUCTION: The Mothers' Object Relations Scale (MORS) was developed by John M. Oates (Open University, Milton Keynes, UK) in the late 1990s. The MORS is an appropriate instrument for gathering parental perceptions about the child and the parent-infant relationship. The questionnaire and its short form were improved further and validated in British and Hungarian samples in the beginning of the 2000s and the questionnaire was used in several applied studies in the UK where its predictive validity was further confirmed. METHODS: The development and validation phases were based on small samples. The diverse social-demographic characteristics of the For Healthy Offspring project, allowed for further testing the reliability and validity of the Hungarian short-form in a large (n=1164) sample. RESULTS: High internal consistency was found in the original and the imputed data obtained from parents of 0-3-year old children for both of H-MORS-SF dimensions: Invasion and Warmth. The scales had interpretable and systematic cross-correlations with measures of infant temperament (IBQ-R, ECBQ) and mental state (DS1K) of both parents. These results confirm and exceed the previous results based on small samples. CONCLUSION: Given the convincing psychometric indicators and its fast and simple usage, the H-MORS-SF can be considered as an effective preventive screening test for monitoring the developing parent-infant relationship, therefore we suggest its use for professionals working in developmental psychology, child health and social fields.
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Relações Mãe-Filho , Mães/estatística & dados numéricos , Apego ao Objeto , Inquéritos e Questionários/normas , Adulto , Fatores Etários , Análise por Conglomerados , Formação de Conceito , Escolaridade , Emoções , Relações Pai-Filho , Feminino , Humanos , Hungria , Masculino , Valor Preditivo dos Testes , Psicometria , Reprodutibilidade dos Testes , Estudos de Amostragem , Fatores Sexuais , Reino UnidoRESUMO
BACKGROUND: A commonly used method for measuring frailty is the accumulation of deficits expressed as a frailty index (FI). FIs can be readily adapted to many databases, as the parameters to use are not prescribed but rather reflect a subset of extracted features (variables). Unfortunately, the structure of many databases does not permit the direct extraction of a suitable subset, requiring additional effort to determine and verify the value of features for each record and thus significantly increasing cost. OBJECTIVE: Our objective is to describe how an artificial intelligence (AI) optimization technique called partial genetic algorithms can be used to refine the subset of features used to calculate an FI and favor features that have the least cost of acquisition. METHODS: This is a secondary analysis of a residential care database compiled from 10 facilities in Queensland, Australia. The database is comprised of routinely collected administrative data and unstructured patient notes for 592 residents aged 75 years and over. The primary study derived an electronic frailty index (eFI) calculated from 36 suitable features. We then structurally modified a genetic algorithm to find an optimal predictor of the calculated eFI (0.21 threshold) from 2 sets of features. Partial genetic algorithms were used to optimize 4 underlying classification models: logistic regression, decision trees, random forest, and support vector machines. RESULTS: Among the underlying models, logistic regression was found to produce the best models in almost all scenarios and feature set sizes. The best models were built using all the low-cost features and as few as 10 high-cost features, and they performed well enough (sensitivity 89%, specificity 87%) to be considered candidates for a low-cost frailty screening test. CONCLUSIONS: In this study, a systematic approach for selecting an optimal set of features with a low cost of acquisition and performance comparable to the eFI for detecting frailty was demonstrated on an aged care database. Partial genetic algorithms have proven useful in offering a trade-off between cost and accuracy to systematically identify frailty.
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Group IVA cytosolic phospholipase A(2) (cPLA(2)α) catalyzes the first step in the arachidonic acid cascade leading to the synthesis of important lipid mediators, the prostaglandins and leukotrienes. We previously described a patient deficient in cPLA(2)α activity, which was associated with mutations in both alleles encoding the enzyme. In this paper, we describe the biochemical characterization of each of these mutations. Using saturating concentrations of calcium, we showed that the R485H mutant was nearly devoid of any catalytic activity, that the S111P mutation did not affect the enzyme activity, and that the known K651R polymorphism was associated with activity slightly higher than that of the wild type. Using MDCK cells, we showed that translocation to the Golgi in response to serum activation was impaired for the S111P mutant but not for the other mutants. Using immortalized mouse lung fibroblasts lacking endogenous cPLA(2)α activity, we showed that both mutations S111P and R485H/K651R caused a profound defect in the enzyme catalytic activity in response to cell stimulation with serum. Taken together, our results show that the S111P mutation hampers calcium binding and membrane translocation without affecting the catalytic activity, and that the mutation R485H does not affect membrane translocation but blocks catalytic activity that leads to inactivation of the enzyme. Interestingly, our results show that the common K651R polymorphism confers slightly higher activity to the enzyme, suggesting a role of this residue in favoring a catalytically active conformation of cPLA(2)α. Our results define how the mutations negatively influence cPLA(2)α function and explain the inability of the proband to release arachidonic acid for eicosanoid production.
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Fosfolipases A2 do Grupo IV/metabolismo , Mutação , Animais , Biocatálise , Linhagem Celular , Cães , Fosfolipases A2 do Grupo IV/deficiência , Fosfolipases A2 do Grupo IV/genética , Humanos , Camundongos , Camundongos Knockout , Transporte ProteicoRESUMO
Naproxen ((S)-6-methoxy-α-methyl-2-naphthaleneacetic acid) is a powerful non-selective non-steroidal anti-inflammatory drug that is extensively used as a prescription and over-the-counter medication. Naproxen exhibits gastrointestinal toxicity, but its cardiovascular toxicity may be reduced compared with other drugs in its class. Despite the fact that naproxen has been marketed for many years, the molecular basis of its interaction with cyclooxygenase (COX) enzymes is unknown. We performed a detailed study of naproxen-COX-2 interactions using site-directed mutagenesis, structure-activity analysis, and x-ray crystallography. The results indicate that each of the pendant groups of the naphthyl scaffold are essential for COX inhibition, and only minimal substitutions are tolerated. Mutation of Trp-387 to Phe significantly reduced inhibition by naproxen, a result that appears unique to this inhibitor. Substitution of S or CH(2) for the O atom of the p-methoxy group yielded analogs that were not affected by the W387F substitution and that exhibited increased COX-2 selectivity relative to naproxen. Crystallization and x-ray analysis yielded structures of COX-2 complexed to naproxen and its methylthio analog at 1.7 and 2.3 Å resolution, respectively. The combination of mutagenesis, structure analysis, and x-ray crystallography provided comprehensive information on the unique interactions responsible for naproxen binding to COX-2.
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Anti-Inflamatórios não Esteroides/química , Ciclo-Oxigenase 2/química , Naproxeno/química , Substituição de Aminoácidos , Animais , Cristalografia por Raios X , Humanos , Camundongos , Mutagênese Sítio-Dirigida , Mutação de Sentido Incorreto , Ligação ProteicaRESUMO
Cytosolic phospholipase A2alpha (cPLA2alpha) hydrolyzes arachidonic acid from cellular membrane phospholipids, thereby providing enzymatic substrates for the synthesis of eicosanoids, such as prostaglandins and leukotrienes. Considerable understanding of cPLA2alpha function has been derived from investigations of the enzyme and from cPLA2alpha-null mice, but knowledge of discrete roles for this enzyme in humans is limited. We investigated a patient hypothesized to have an inherited prostanoid biosynthesis deficiency due to his multiple, complicated small intestinal ulcers despite no use of cyclooxygenase inhibitors. Levels of thromboxane B2 and 12-hydroxyeicosatetraenoic acid produced by platelets and leukotriene B4 released from calcium ionophore-activated blood were markedly reduced, indicating defective enzymatic release of the arachidonic acid substrate for the corresponding cyclooxygenase and lipoxygenases. Platelet aggregation and degranulation induced by adenosine diphosphate or collagen were diminished but were normal in response to arachidonic acid. Two heterozygous single base pair mutations and a known SNP were found in the coding regions of the patient's cPLA2alpha genes (p.[Ser111Pro]+[Arg485His; Lys651Arg]). The total PLA2 activity in sonicated platelets was diminished, and the urinary metabolites of prostacyclin, prostaglandin E2, prostaglandin D2, and thromboxane A2 were also reduced. These findings characterize what we believe is a novel inherited deficiency of cPLA2.
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Plaquetas/metabolismo , Eicosanoides/metabolismo , Fosfolipases A2 do Grupo IV/deficiência , Fosfolipases A2 do Grupo IV/genética , Intestino Delgado/patologia , Ácido Araquidônico/metabolismo , Cálcio/metabolismo , Fosfolipases A2 do Grupo IV/fisiologia , Heterozigoto , Humanos , Ionóforos/metabolismo , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Prostaglandina D2/metabolismo , Prostaglandina-Endoperóxido Sintases/metabolismo , Tromboxano A2/metabolismo , Úlcera/patologiaRESUMO
Background: The World Health Organization and others promote responsive caregiving to support all children to thrive, particularly in low- and middle-income countries. The 14-item Mother's Object Relations Scales - Short Form (MORS-SF) may be of use in research and public health programmes because of its basis in attachment theory and ability to capture parental feelings towards their child. Methods: We culturally adapted the MORS-SF for use with mothers in the SPRING home visits trial when their infants were 12 months old. The same dyads were assessed using the HOME inventory concurrently and Bayley Scales of Infant Development III (BSID-III) at 18 months of age. Mixed effects linear regression was used to examine associations between MORS-SF (explanatory variable) and HOME-IT, and the cognitive, language and motor domains of BSID-III (outcome variables). Results: 1273 dyads completed all assessments. For the motor and language BSID-III scales and for HOME-IT there were strong and positive associations with the MORS-SF warmth sub-scale, and strong and negative associations with the invasion sub-scale. Important but less strong associations were seen with the BSID-III cognitive scale. Evidence of interaction suggested that both are individually important for child development. Conclusions: This is the first time MORS-SF has been used in India where optimising responsive caregiving is of importance in supporting all children to reach their potential. It is also the first time that the tool has been used in relation to child development. MORS-SF could be a valuable addition to evaluation in early childhood development.
RESUMO
Expression of cyclooxygenase-2 (COX-2) is associated with the development of many pathologic conditions. The product of COX-2, prostaglandin H(2) (PGH(2)), can spontaneously rearrange to form reactive gamma-ketoaldehydes called levuglandins (LGs). This gamma-ketoaldehyde structure confers a high degree of reactivity on the LGs, which rapidly form covalent adducts with primary amines of protein residues. Formation of LG adducts of proteins has been demonstrated in pathologic conditions (e.g., increased levels in the hippocampus in Alzheimer's disease) and during physiologic function (platelet activation). On the basis of knowledge that lipid modification of proteins is known to cause their translocation and to alter their function, we hypothesize that modification of proteins by LG could have functional consequences. Testing this hypothesis requires an experimental approach that discriminates between the effects of protein modification by LG and the effects of cyclooxygenase-derived prostanoids acting through their G-protein coupled receptors. To achieve this goal, we have synthesized and evaluated a series of scavengers that react with LG with a potency more than 2 orders of magnitude greater than that with the epsilon-amine of lysine. A subset of these scavengers are shown to block the formation of LG adducts of proteins in cells without inhibiting the catalytic activity of the cyclooxygenases. Ten of these selective scavengers did not produce cytotoxicity. These results demonstrate that small molecules can scavenge LGs in cells without interfering with the formation of prostaglandins. They also provide a working hypothesis for the development of pharmacologic agents that could be used in experimental animals in vivo to assess the pathophysiological contribution of levuglandins in diseases associated with cyclooxygenase up-regulation.
Assuntos
Aminas/química , Prostaglandinas H/química , Prostaglandinas/biossíntese , Aminas/síntese química , Plaquetas/metabolismo , Linhagem Celular Tumoral , Ciclo-Oxigenase 2/química , Ciclo-Oxigenase 2/metabolismo , Células Hep G2 , Humanos , Prostaglandinas H/metabolismo , Piridoxamina/químicaRESUMO
Lipid peroxidation generates reactive dicarbonyls including isolevuglandins (IsoLGs) and malondialdehyde (MDA) that covalently modify proteins. Humans with familial hypercholesterolemia (FH) have increased lipoprotein dicarbonyl adducts and dysfunctional HDL. We investigate the impact of the dicarbonyl scavenger, 2-hydroxybenzylamine (2-HOBA) on HDL function and atherosclerosis in Ldlr-/- mice, a model of FH. Compared to hypercholesterolemic Ldlr-/- mice treated with vehicle or 4-HOBA, a nonreactive analogue, 2-HOBA decreases atherosclerosis by 60% in en face aortas, without changing plasma cholesterol. Ldlr-/- mice treated with 2-HOBA have reduced MDA-LDL and MDA-HDL levels, and their HDL display increased capacity to reduce macrophage cholesterol. Importantly, 2-HOBA reduces the MDA- and IsoLG-lysyl content in atherosclerotic aortas versus 4-HOBA. Furthermore, 2-HOBA reduces inflammation and plaque apoptotic cells and promotes efferocytosis and features of stable plaques. Dicarbonyl scavenging with 2-HOBA has multiple atheroprotective effects in a murine FH model, supporting its potential as a therapeutic approach for atherosclerotic cardiovascular disease.