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1.
Commun Biol ; 7(1): 504, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671141

RESUMO

Essential tremor (ET) is a prevalent neurological disorder with a largely unknown underlying biology. In this genome-wide association study meta-analysis, comprising 16,480 ET cases and 1,936,173 controls from seven datasets, we identify 12 sequence variants at 11 loci. Evaluating mRNA expression, splicing, plasma protein levels, and coding effects, we highlight seven putative causal genes at these loci, including CA3 and CPLX1. CA3 encodes Carbonic Anhydrase III and carbonic anhydrase inhibitors have been shown to decrease tremors. CPLX1, encoding Complexin-1, regulates neurotransmitter release. Through gene-set enrichment analysis, we identify a significant association with specific cell types, including dopaminergic and GABAergic neurons, as well as biological processes like Rho GTPase signaling. Genetic correlation analyses reveals a positive association between ET and Parkinson's disease, depression, and anxiety-related phenotypes. This research uncovers risk loci, enhancing our knowledge of the complex genetics of this common but poorly understood disorder, and highlights CA3 and CPLX1 as potential therapeutic targets.


Assuntos
Tremor Essencial , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Tremor Essencial/genética , Humanos , Polimorfismo de Nucleotídeo Único , Loci Gênicos
2.
Curr Sports Med Rep ; 23(2): 30-31, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38315427
3.
J Prev Alzheimers Dis ; 10(4): 669-674, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37874087

RESUMO

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative disease with complex disease etiology and pathological processes. These include formation of plaques and tangles, aberrant lipid processing, neuroinflammation, cerebrovascular dysregulation, ion channel and mitochondrial dysfunction, and oxidative stress. Disease-modifying therapies focusing on all these different facets are needed. TW001 is an oral formulation with the radical scavenger edaravone as its active ingredient, targeting oxidative stress. OBJECTIVES: This manuscript describes the trial design for Phase IIA Alzheimer Study Using oRal Edaravone (ASURE). METHODS: ASURE is a randomized, placebo-controlled, proof-of-concept study aiming to evaluate safety and target engagement following administration of TW001 in early AD patients. Patients should have a biomarker confirmed diagnosis to be included in the trial and will be treated for 90 days. The primary endpoints include safety and effect of TW001 on oxidative stress biomarkers. Exploratory endpoints focus on a panel of AD(-related) fluid-based biomarkers and EEG. In addition, a recently developed cognitive functional composite (CFC) score will measure early signs of cognitive and functional effects of TW001. RESULTS: This article outlines the design of the clinical study, no results are included. CONCLUSIONS: The ASURE trial design is discussed, with a particular focus on fluid biomarkers, EEG, and CFC as endpoints. By testing multiple measures related to pathology, pharmacodynamics, EEG as proxy for cognition, and cognitive functional scores, it is expected that small changes will be detectable in trials of shorter duration. Moreover, the wide range of endpoints allows to make well-informed decisions for designing pivotal studies later.


Assuntos
Doença de Alzheimer , Doenças Neurodegenerativas , Humanos , Doença de Alzheimer/psicologia , Edaravone/uso terapêutico , Resultado do Tratamento , Biomarcadores , Ensaios Clínicos Controlados Aleatórios como Assunto
4.
Blood Adv ; 7(17): 4936-4949, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37307200

RESUMO

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of infancy that is commonly associated with a life-threatening thrombocytopenic condition, Kasabach-Merritt phenomenon (KMP). Platelet CLEC-2, tumor podoplanin interaction is considered the key mechanism of platelet clearance in these patients. Here, we aimed to assess platelet functionality in such patients. Three groups of 6 to 9 children were enrolled: group A with KHE/KMP without hematologic response (HR) to therapy; group B with KHE/KMP with HR; and group C with healthy children. Platelet functionality was assessed by continuous and end point flow cytometry, low-angle light scattering analysis (LaSca), fluorescent microscopy of blood smears, and ex vivo thrombi formation. Platelet integrin activation in response to a combination of CRP (GPVI agonist) and TRAP-6 (PAR1 agonist), as well as calcium mobilization and integrin activation in response to CRP or rhodocytin (CLEC-2 agonist) alone, were significantly diminished in groups A and B. At the same time, platelet responses to ADP with or without TRAP-6 were unaltered. Thrombi formation from collagen in parallel plate flow chambers was also noticeably decreased in groups A and B. In silico analysis of these results predicted diminished amounts of CLEC-2 on the platelet surface of patients, which was further confirmed by immunofluorescence microscopy and flow cytometry. In addition, we also noted a decrease in GPVI levels on platelets from group A. In KHE/KMP, platelet responses induced by CLEC-2 or GPVI activation are impaired because of the diminished number of receptors on the platelet surface. This impairment correlates with the severity of the disease and resolves as the patient recovers.


Assuntos
Hemangioendotelioma , Síndrome de Kasabach-Merritt , Sarcoma de Kaposi , Humanos , Criança , Síndrome de Kasabach-Merritt/diagnóstico , Síndrome de Kasabach-Merritt/complicações , Síndrome de Kasabach-Merritt/terapia , Hemangioendotelioma/diagnóstico , Hemangioendotelioma/complicações , Hemangioendotelioma/terapia , Sarcoma de Kaposi/complicações , Sarcoma de Kaposi/terapia , Lectinas Tipo C
5.
JACC Case Rep ; 4(17): 1094-1097, 2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36124149

RESUMO

Swimming-induced pulmonary edema is a leading cause of triathlon-associated emergencies and death. Cold water immersion, female sex, age>50, and wetsuit compression are associated risk factors. Pathophysiology is due to increased central blood pooling, leading to increased pulmonary capillary wedge pressure. Treatment is focused on prevention; however, recurrence is common. (Level of Difficulty: Intermediate.).

6.
Methodist Debakey Cardiovasc J ; 17(4): 48-59, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34824681

RESUMO

Early identification and mitigation of sex-specific cardiovascular disease risk factors is a potential trajectory-changing strategy to improve lifelong cardiovascular health in women. These sex-specific risk factors include adverse pregnancy outcomes, polycystic ovarian syndrome, and premature menopause. We start by discussing the impact and management of risk factors for adverse pregnancy outcomes as an upstream intervention for cardiovascular disease risk reduction and then address the long-term effect and mitigation of sex-specific risk factors for cardiovascular disease.


Assuntos
Doenças Cardiovasculares , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Gravidez , Medição de Risco , Fatores de Risco , Útero
7.
Sci Rep ; 11(1): 9401, 2021 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-33931737

RESUMO

Immune thrombocytopenia (ITP) is believed to be associated with platelet function defects. However, their mechanisms are poorly understood, in particular with regard to differences between ITP phases, patient age, and therapy. We investigated platelet function and bleeding in children with either persistent or chronic ITP, with or without romiplostim therapy. The study included 151 children with ITP, of whom 56 had disease duration less than 12 months (grouped together as acute/persistent) and 95 were chronic. Samples of 57 healthy children were used as controls, while 5 patients with leukemia, 5 with aplastic anemia, 4 with MYH9-associated thrombocytopenia, and 7 with Wiskott-Aldrich syndrome were used as non-ITP thrombocytopenia controls. Whole blood flow cytometry revealed that platelets in both acute/persistent and chronic ITP were increased in size compared with healthy donors. They were also pre-activated as assessed by PAC1, CD62p, cytosolic calcium, and procoagulant platelet levels. This pattern was not observed in other childhood thrombocytopenias. Pre-activation by CD62p was higher in the bleeding group in the chronic ITP cohort only. Romiplostim treatment decreased size and pre-activation of the patient platelets, but not calcium. Our data suggest that increased size, pre-activation, and cytosolic calcium are common for all ITP platelets, but their association with bleeding could depend on the disease phase.


Assuntos
Plaquetas/efeitos dos fármacos , Sinalização do Cálcio , Hemorragia/etiologia , Púrpura Trombocitopênica Idiopática/sangue , Receptores Fc/uso terapêutico , Proteínas Recombinantes de Fusão/uso terapêutico , Trombopoetina/uso terapêutico , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Testes de Função Plaquetária , Púrpura Trombocitopênica Idiopática/complicações , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Proteínas Recombinantes de Fusão/farmacologia , Trombopoetina/farmacologia
9.
Pflugers Arch ; 472(5): 527-545, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32415463

RESUMO

Paralysis is a frequent phenomenon in many diseases, and to date, only functional electrical stimulation (FES) mediated via the innervating nerve can be employed to restore skeletal muscle function in patients. Despite recent progress, FES has several technical limitations and significant side effects. Optogenetic stimulation has been proposed as an alternative, as it may circumvent some of the disadvantages of FES enabling cell type-specific, spatially and temporally precise stimulation of cells expressing light-gated ion channels, commonly Channelrhodopsin2. Two distinct approaches for the restoration of skeletal muscle function with optogenetics have been demonstrated: indirect optogenetic stimulation through the innervating nerve similar to FES and direct optogenetic stimulation of the skeletal muscle. Although both approaches show great promise, both have their limitations and there are several general hurdles that need to be overcome for their translation into clinics. These include successful gene transfer, sustained optogenetic protein expression, and the creation of optically active implantable devices. Herein, a comprehensive summary of the underlying mechanisms of electrical and optogenetic approaches is provided. With this knowledge in mind, we substantiate a detailed discussion of the advantages and limitations of each method. Furthermore, the obstacles in the way of clinical translation of optogenetic stimulation are discussed, and suggestions on how they could be overcome are provided. Finally, four specific examples of pathologies demanding novel therapeutic measures are discussed with a focus on the likelihood of direct versus indirect optogenetic stimulation.


Assuntos
Terapia por Estimulação Elétrica/métodos , Músculo Esquelético/metabolismo , Optogenética/métodos , Pesquisa Translacional Biomédica/métodos , Animais , Humanos , Contração Muscular , Músculo Esquelético/fisiologia
10.
JMIR Med Inform ; 7(4): e14756, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31579025

RESUMO

BACKGROUND: Patients hospitalized with heart failure suffer the highest rates of 30-day readmission among other clinically defined patient populations in the United States. Investigation into the predictability of 30-day readmissions can lead to clinical decision support tools and targeted interventions that can help care providers to improve individual patient care and reduce readmission risk. OBJECTIVE: This study aimed to develop a dynamic readmission risk prediction model that yields daily predictions for patients hospitalized with heart failure toward identifying risk trajectories over time and identifying clinical predictors associated with different patterns in readmission risk trajectories. METHODS: A two-stage predictive modeling approach combining logistic and beta regression was applied to electronic health record data accumulated daily to predict 30-day readmission for 534 hospital encounters of patients with heart failure over 2750 patient days. Unsupervised clustering was performed on predictions to uncover time-dependent trends in readmission risk over the patient's hospital stay. We used data collected between September 1, 2013, and August 31, 2015, from a community hospital in Maryland (United States) for patients with a primary diagnosis of heart failure. Patients who died during the hospital stay or were transferred to other acute care hospitals or hospice care were excluded. RESULTS: Readmission occurred in 107 (107/534, 20.0%) encounters. The out-of-sample area under curve for the 2-stage predictive model was 0.73 (SD 0.08). Dynamic clinical predictors capturing laboratory results and vital signs had the highest predictive value compared with demographic, administrative, medical, and procedural data included. Unsupervised clustering identified four risk trajectory groups: decreasing risk (131/534, 24.5% encounters), high risk (113/534, 21.2%), moderate risk (177/534, 33.1%), and low risk (113/534, 21.2%). The decreasing risk group demonstrated change in average probability of readmission from admission (0.69) to discharge (0.30), whereas the high risk (0.75), moderate risk (0.61), and low risk (0.39) groups maintained consistency over the hospital course. A higher level of hemoglobin, larger decrease in potassium and diastolic blood pressure from admission to discharge, and smaller number of past hospitalizations are associated with decreasing readmission risk (P<.001). CONCLUSIONS: Dynamically predicting readmission and quantifying trends over patients' hospital stay illuminated differing risk trajectory groups. Identifying risk trajectory patterns and distinguishing predictors may shed new light on indicators of readmission and the isolated effects of the index hospitalization.

11.
Amyloid ; 25(3): 174-179, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30169971

RESUMO

INTRODUCTION: Diagnostic delay of cardiac amyloidosis (CAm) continues to challenge clinicians. We investigated features associated with delay and ascertained if a diagnostic delay had negative implications for the patient. METHODS: We performed a retrospective chart review identifying 82 subjects with biopsy-proven and mass-spectrometry-identified CAm with clinical and epidemiologic data including first potential symptom of amyloidosis. Pathology slides were scored for extent of amyloid. Robust statistical analyses including generalized linear and ordered logistic regression analysis were performed. RESULTS: There was a 22 month (median) delay in diagnosis, more pronounced (34 months) in subjects with transthyretin (ATTR) amyloidosis. Seven factors predict a delayed diagnosis including ATTR amyloid type (ratio =2.17, 95% CI 1.31-3.59), having carpal tunnel syndrome (2.13, CI 1.49-3.03) and age <70 at first symptom (1.85, CI 1.30-2.61). Individuals with delays of 1+ years had higher levels of NT proBNP (4451 vs. 2559 pg/mL, p = .016) and longer PR intervals (225 vs. 162 ms, p < .001) at the time of diagnosis. CONCLUSIONS: Diagnostic delays negatively affect cardiac function. Of the predictive clinical features, carpal tunnel syndrome was frequent and its presence should lead to a more aggressive analysis for CAm in the appropriate clinical settings.


Assuntos
Amiloidose/diagnóstico , Diagnóstico Tardio , Idoso , Neuropatias Amiloides Familiares/diagnóstico , Biópsia , Feminino , Humanos , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Miocárdio/patologia , Estudos Retrospectivos
12.
Am J Case Rep ; 18: 1148-1152, 2017 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-29081491

RESUMO

BACKGROUND Spontaneous retroperitoneal hemorrhage (SRH) is a rare and difficult-to-diagnose entity. It is not associated with trauma, pathology, or iatrogenic manipulations. Few cases have been reported, with the only precipitating factor recognized being bleeding diatheses such as anticoagulation states, inherited coagulopathies, and hemodialysis. However, none of these have been described in combination with septic shock, which itself is associated with platelet dysfunction, coagulation dysfunction, and vasculopathy. CASE REPORT Our case involves an elderly man presenting with altered mental status of unknown etiology, in addition to hemodynamic instability, presumably due to septic shock, without any overt signs of bleeding. After his initial exam revealed lower-extremity edema and decubitus ulcers, a venous Doppler was performed, which revealed extensive deep vein thrombosis. It was unknown whether the sepsis or DVT occurred first. Therapeutic anticoagulation with heparin was subsequently started. On hospital day 4, a CT abdomen with contrast identified retroperitoneal hematoma after the patient's hemoglobin lowered without any overt signs of bleeding. The diagnosis of spontaneous retroperitoneal hematoma was one of exclusion and posed a therapeutic dilemma (conservative versus invasive management). CONCLUSIONS Sepsis-related coagulopathy and heparin use in an elderly patient predisposed him to an iliopsoas hematoma. In this case, conservative management with reversal of anticoagulation and blood transfusion was sufficient to stabilize the patient.


Assuntos
Hematoma/complicações , Espaço Retroperitoneal/diagnóstico por imagem , Choque Séptico/complicações , Trombose Venosa/complicações , Idoso , Hematoma/diagnóstico por imagem , Humanos , Masculino , Trombose Venosa/diagnóstico por imagem
13.
J Card Fail ; 23(8): 652-655, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28624653

RESUMO

BACKGROUND: The presence of giant ring mitochondria on endomyocardial biopsy is rarely reported and does not have a well-defined differential diagnosis. METHODS: We report the case of a 54-year-old man with heart failure and preserved ejection fraction and left ventricular hypertrophy, initially thought to have an infiltrative cardiomyopathy. RESULTS: The patient was found to have extensive vacuolization caused by giant ring mitochondria on endomyocardial biopsy. Mitochondrial genetic testing revealed an A3243G mutation in the MT-TL1 gene, which is a mitochondrial encoded transfer RNA-leucine molecule. CONCLUSIONS: Mitochondrial disease should be considered in patients presenting with unexplained cardiomyopathy and skeletal muscle, cerebral, or metabolic abnormalities. In this case, the presence of unexpected extensive cardiomyocyte vacuolization and giant, ring-shaped mitochondria on endomyocardial biopsy prompted mitochondrial genetic testing, which ultimately resulted in the correct diagnosis and treatment.


Assuntos
Genes Mitocondriais/genética , Insuficiência Cardíaca/genética , Leucoencefalopatias/genética , Mutação/genética , RNA de Transferência de Leucina/genética , Insuficiência Cardíaca/diagnóstico por imagem , Humanos , Leucoencefalopatias/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Linhagem
14.
Med Gas Res ; 7(1): 1-8, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28480026

RESUMO

Exercise training confers sustainable protection against ischemia/reperfusion injury. However, the mechanism by which this process occurs is not fully understood. Previously, it was shown that ß3-adrenergic receptors (ß3-ARs) play a critical role in regulating the activation of endothelial nitric oxide synthase (eNOS) in response to exercise and play a critical role in exercise-mediated cardioprotection. Intriguingly, a deficiency in ß3-ARs led to increased myocardial injury following exercise training. The purpose of the current study was to determine mechanisms by which ß3-ARs are linked to eNOS activation and to determine the mechanism responsible for the exacerbated ischemia/reperfusion injury displayed by ß3-AR deficient (ß3-AR KO) mice after exercise training. Wild-type (n = 37) and ß3-AR KO (n = 40) mice were subjected to voluntary wheel running for 4 weeks. Western blot analysis revealed that neither protein kinase B nor protein kinase A linked ß3-ARs to eNOS following exercise training. However, analysis revealed a role for AMP-activated protein kinase (AMPK). Specifically, exercise training increased the phosphorylation of AMPK in the hearts of wild-type mice, but failed to do so in the hearts of ß3-AR KO mice. Additional studies revealed that exercise training rendered eNOS less coupled and increased NOS-dependent superoxide levels in ß3-AR KO mice. Finally, supplementing ß3-AR KO mice with the eNOS coupler, tetrahydrobiopterin, during the final week of exercise training reduced myocardial infarction. These findings provide important information that exercise training protects the heart in the setting of myocardial ischemia/reperfusion injury by activating and coupling eNOS via the stimulation of a ß3-AR-AMPK signaling pathway.

15.
Int J Hematol ; 105(6): 841-848, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28271416

RESUMO

It has been suggested that platelet function in chronic immune thrombocytopenic purpura (ITP) may be abnormal. Thrombopoietin mimetics used for treatment can affect it, but the data remain limited. We investigated platelet function of 20 children diagnosed with severe ITP (aged 1-16 years, 12 females and eight males). Platelet functional activity in whole blood was characterized by flow cytometry before and after stimulation with SFLLRN plus collagen-related peptide. Levels of CD42b, PAC1, and CD62P, but not CD61 or annexin V, were significantly increased (P < 0.05) in resting platelets of patients before treatment compared with healthy donors. On average, PAC1 and CD62P in patients after activation were also significantly elevated, although some patients failed to activate integrins. Romiplostim (1-15 µg/kg/week s.c.) was prescribed to seven patients, with clinical improvement in six. Interestingly, one patient had clinical improvement without platelet count increase. Eltrombopag (25-75 mg/day p.o.) was given to four patients, with positive response in one. Others switched to romiplostim, with one stable positive response, one unstable positive response, and one non-responding. Platelet quality improved with romiplostim treatment, and their parameters approached the normal values. Our results suggest that platelets in children with severe ITP are pre-activated and abnormal, but improve with treatment.


Assuntos
Benzoatos/administração & dosagem , Plaquetas/metabolismo , Hemorragia , Hidrazinas/administração & dosagem , Púrpura Trombocitopênica Idiopática , Pirazóis/administração & dosagem , Receptores Fc , Proteínas Recombinantes de Fusão , Trombopoetina , Adolescente , Anexina A5/sangue , Antígenos CD/sangue , Criança , Pré-Escolar , Feminino , Hemorragia/sangue , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Humanos , Lactente , Masculino , Contagem de Plaquetas , Púrpura Trombocitopênica Idiopática/sangue , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Receptores Fc/administração & dosagem , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/sangue , Proteínas Recombinantes de Fusão/administração & dosagem , Proteínas Recombinantes de Fusão/efeitos adversos , Trombopoetina/administração & dosagem , Trombopoetina/efeitos adversos
16.
Pediatr Blood Cancer ; 62(9): 1597-600, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25946618

RESUMO

BACKGROUND: Diamond Blackfan anemia (DBA) is a genetically and clinically heterogeneous ribosomopathy and inherited bone marrow failure syndrome characterized by anemia, reticulocytopenia, and decreased erythroid precursors in the bone marrow with an increased risk of malignancy and, in approximately 50%, physical abnormalities. METHODS: We retrospectively analyzed clinical data from 77 patients with DBA born in the Russian Federation from 1993 to 2014. In 74 families there was one clinically affected individual; in only three instances a multiplex family was identified. Genomic DNA from 57 DBA patients and their first-degree relatives was sequenced for mutations in RPS19, RPS10, RPS24, RPS26, RPS7, RPS17, RPL5, RPL11, RPL35a, and GATA1. RESULTS: Severe anemia presented before 8 months of age in all 77 patients; before 2 months in 61 (78.2%); before 4 months in 71 (92.2%). Corticosteroid therapy was initiated after 1 year of age in the majority of patients. Most responded initially to steroids, while 5 responses were transient. Mutations in RP genes were detected in 35 of 57 patients studied: 15 in RPS19, 6 in RPL5, 3 in RPS7, 3 each in RPS10, RPS26, and RPL11 and 1 each in RPS24 and RPL35a; 24 of these mutations have not been previously reported. One patient had a balanced chromosomal translocation involving RPS19. No mutations in GATA1 were found. CONCLUSION: In our cohort from an ethnically diverse population the distribution of mutations among RP genes was approximately the same as was reported by others, although within genotypes most of the mutations had not been previously reported.


Assuntos
Anemia de Diamond-Blackfan/genética , Fator de Transcrição GATA1/genética , Mutação , Proteínas Ribossômicas/genética , Anormalidades Múltiplas/genética , Adolescente , Anemia de Diamond-Blackfan/epidemiologia , Criança , Pré-Escolar , Anormalidades Craniofaciais/genética , Análise Mutacional de DNA , Feminino , Fator de Transcrição GATA1/deficiência , Heterogeneidade Genética , Genótipo , Cardiopatias Congênitas/genética , Humanos , Lactente , Masculino , Fenótipo , Estudos Retrospectivos , Proteínas Ribossômicas/deficiência , Federação Russa/epidemiologia , Análise de Sequência de DNA , Adulto Jovem
18.
Comput Intell Neurosci ; 2014: 419743, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25587265

RESUMO

Condition diagnosis of multiple bearings system is one of the requirements in industry field, because bearings are used in many equipment and their failure can result in total breakdown. Conditions of bearings commonly are reflected by vibration signals data. In multiple bearing condition diagnosis, it will involve many types of vibration signals data; thus, consequently, it will involve many features extraction to obtain precise condition diagnosis. However, large number of features extraction will increase the complexity of the diagnosis system. Therefore, in this paper, we presented a diagnosis method which is hybridization of adaptive genetic algorithms (AGAs), back propagation neural networks (BPNNs), and grey relational analysis (GRA) to diagnose the condition of multiple bearings system. AGAs are used in the diagnosis algorithm to determine the best initial weights of BPNNs in order to improve the diagnosis accuracy. In addition, GRA is applied to determine and select the dominant features from the vibration signal data which will provide good diagnosis of multiple bearings system in less features extraction. The experiments results show that AGAs-BPNNs with GRA approaches can increase the accuracy of diagnosis in shorter processing time, compared with the AGAs-BPNNs without the GRA.


Assuntos
Algoritmos , Análise de Falha de Equipamento/métodos , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador/instrumentação , Humanos , Vibração
19.
J Mol Cell Cardiol ; 62: 8-17, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23643588

RESUMO

RATIONALE: Stimulation of ß3-adrenoreceptors (ß3-AR) blunts contractility and improves chronic left ventricular function in hypertrophied and failing hearts in a neuronal nitric oxide synthase (nNOS) dependent manner. nNOS can be regulated by post-translational modification of stimulatory phosphorylation residue Ser1412 and inhibitory residue Ser847. However, the role of phosphorylation of these residues in cardiomyocytes and ß3-AR protective signaling has yet to be explored. OBJECTIVE: We tested the hypothesis that ß3-AR regulation of myocyte stress requires changes in nNOS activation mediated by differential nNOS phosphorylation. METHODS AND RESULTS: Endothelin (ET-1) or norepinephrine induced hypertrophy in rat neonatal ventricular cardiomyocytes (NRVMs) was accompanied by increased ß3-AR gene expression. Co-administration of the ß3-AR agonist BRL-37433 (BRL) reduced cell size and reactive oxygen species (ROS) generation, while augmenting NOS activity. BRL-dependent augmentation of NOS activity and ROS suppression due to NE were blocked by inhibiting nNOS (L-VNIO). BRL augmented nNOS phosphorylation at Ser1412 and dephosphorylation at Ser847. Cells expressing constitutively dephosphorylated Ser1412A or phosphorylated Ser847D nNOS mutants displayed reduced nNOS activity and a lack of BRL modulation. BRL also failed to depress ROS from NE in cells with nNOS-Ser847D. Inhibiting Akt decreased BRL-induced nNOS-Ser1412 phosphorylation and NOS activation, whereas Gi/o blockade blocked BRL-regulation of both post-translational modifications, preventing enhancement of NOS activity and ROS reduction. BRL resulted in near complete dephosphorylation of Ser847 and a moderate rise in Ser1412 phosphorylation in mouse myocardium exposed to chronic pressure-overload. CONCLUSION: ß3-AR regulates myocardial NOS activity and ROS via activation of nNOS involving reciprocal changes in phosphorylation at two regulatory sites. These data identify a novel and potent anti-oxidant and anti-hypertrophic pathway due to nNOS post-translational modification that is coupled to ß3-AR receptor stimulation.


Assuntos
Antioxidantes/farmacologia , Células Musculares/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Receptores Adrenérgicos beta 3/metabolismo , Agonistas Adrenérgicos beta/farmacologia , Animais , Células Cultivadas , Etanolaminas/farmacologia , Imunoprecipitação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares/efeitos dos fármacos , Fosforilação , Reação em Cadeia da Polimerase , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio
20.
J Cardiovasc Transl Res ; 6(3): 436-45, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23456569

RESUMO

Obesity is associated with increased diastolic stiffness and myocardial steatosis and dysfunction. The impact of aging on the protective effects of caloric restriction (CR) is not clear. We studied 2-month (younger) and 6-7-month (older)-old ob/ob mice and age-matched C57BL/6J controls (WT). Ob/ob mice were assigned to diet ad libitum or CR for 4 weeks. We performed echocardiograms, myocardial triglyceride assays, Oil Red O staining, and measured free fatty acids, superoxide, NOS activity, ceramide levels, and Western blots. In younger mice, CR restored diastolic function, reversed myocardial steatosis, and upregulated Akt phosphorylation. None of these changes was observed in the older mice; however, CR decreased oxidative stress and normalized NOS activity in these animals. Interestingly, myocardial steatosis was not associated with increased ceramide, but CR altered the composition of ceramides. In this model of obesity, aging attenuates the benefits of CR on myocardial structure and function.


Assuntos
Restrição Calórica , Obesidade/dietoterapia , Disfunção Ventricular Esquerda/prevenção & controle , Fatores Etários , Animais , Ceramidas/metabolismo , Diástole , Modelos Animais de Doenças , Ácidos Graxos não Esterificados/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/metabolismo , Miocárdio/patologia , Óxido Nítrico Sintase/metabolismo , Obesidade/complicações , Obesidade/metabolismo , Obesidade/fisiopatologia , Estresse Oxidativo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo , Triglicerídeos/metabolismo , Disfunção Ventricular Esquerda/etiologia , Disfunção Ventricular Esquerda/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Função Ventricular Esquerda , Redução de Peso
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