Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
1.
J Mater Chem B ; 12(13): 3273-3281, 2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38469725

RESUMO

Superoxide, an anionic dioxygen molecule, plays a crucial role in redox regulation within the body but is implicated in various pathological conditions when produced excessively. Efforts to develop superoxide detection strategies have led to the exploration of organic-based contrast agents for magnetic resonance imaging (MRI). This study compares the effectiveness of two such agents, nTMV-TEMPO and kTMV-TEMPO, for detecting superoxide in a mouse liver model with lipopolysaccharide (LPS)-induced inflammation. The study demonstrates that kTMV-TEMPO, with a strategically positioned lysine residue for TEMPO attachment, outperforms nTMV-TEMPO as an MRI contrast agent. The enhanced sensitivity of kTMV-TEMPO is attributed to its more exposed TEMPO attachment site, facilitating stronger interactions with water protons and superoxide radicals. EPR kinetics experiments confirm kTMV-TEMPO's faster oxidation and reduction rates, making it a promising sensor for superoxide in inflamed liver tissue. In vivo experiments using healthy and LPS-induced inflamed mice reveal that reduced kTMV-TEMPO remains MRI-inactive in healthy mice but becomes MRI-active in inflamed livers. The contrast enhancement in inflamed livers is substantial, validating the potential of kTMV-TEMPO for detecting superoxide in vivo. This research underscores the importance of optimizing contrast agents for in vivo imaging applications. The enhanced sensitivity and biocompatibility of kTMV-TEMPO make it a promising candidate for further studies in the realm of medical imaging, particularly in the context of monitoring oxidative stress-related diseases.


Assuntos
Superóxidos , Vírus do Mosaico do Tabaco , Camundongos , Animais , Meios de Contraste/química , Lipopolissacarídeos , Imageamento por Ressonância Magnética/métodos , Fígado
2.
Magn Reson Med ; 91(5): 1822-1833, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38265104

RESUMO

PURPOSE: Pyruvate, produced from either glucose, glycogen, or lactate, is the dominant precursor of cerebral oxidative metabolism. Pyruvate dehydrogenase (PDH) flux is a direct measure of cerebral mitochondrial function and metabolism. Detection of [13 C]bicarbonate in the brain from hyperpolarized [1-13 C]pyruvate using carbon-13 (13 C) MRI provides a unique opportunity for assessing PDH flux in vivo. This study is to assess changes in cerebral PDH flux in response to visual stimuli using in vivo 13 C MRS with hyperpolarized [1-13 C]pyruvate. METHODS: From seven sedentary adults in good general health, time-resolved [13 C]bicarbonate production was measured in the brain using 90° flip angles with minimal perturbation of its precursors, [1-13 C]pyruvate and [1-13 C]lactate, to test the hypothesis that the appearance of [13 C]bicarbonate signals in the brain reflects the metabolic changes associated with neuronal activation. With a separate group of healthy participants (n = 3), the likelihood of the bolus-injected [1-13 C]pyruvate being converted to [1-13 C]lactate prior to decarboxylation was investigated by measuring [13 C]bicarbonate production with and without [1-13 C]lactate saturation. RESULTS: In the course of visual stimulation, the measured [13 C]bicarbonate signal normalized to the total 13 C signal in the visual cortex increased by 17.1% ± 15.9% (p = 0.017), whereas no significant change was detected in [1-13 C]lactate. Proton BOLD fMRI confirmed the regional activation in the visual cortex with the stimuli. Lactate saturation decreased bicarbonate-to-pyruvate ratio by 44.4% ± 9.3% (p < 0.01). CONCLUSION: We demonstrated the utility of 13 C MRS with hyperpolarized [1-13 C]pyruvate for assessing the activation of cerebral PDH flux via the detection of [13 C]bicarbonate production.


Assuntos
Bicarbonatos , Ácido Pirúvico , Adulto , Humanos , Ácido Pirúvico/metabolismo , Bicarbonatos/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Isótopos de Carbono/metabolismo , Ácido Láctico/metabolismo , Oxirredutases/metabolismo
4.
Magn Reson Med ; 87(1): 302-311, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34617626

RESUMO

PURPOSE: Previous cardiac imaging studies using hyperpolarized (HP) [1-13 C]pyruvate were acquired at end-diastole (ED). Little is known about the interaction between cardiac cycle and metabolite content in the myocardium. In this study, we compared images of HP pyruvate and products at end-systole (ES) and ED. METHODS: A dual-phase 13 C MRI sequence was implemented to acquire two sequential HP images within a single cardiac cycle at ES and ED during successive R-R intervals in an interleaved manner. Each healthy volunteer (N = 3) received two injections of HP [1-13 C]pyruvate for the dual-phase imaging on the short-axis and the vertical long-axis planes. Spatial distribution of HP 13 C metabolites at each cardiac phase was correlated to multiphase 1 H MRI to confirm the mechanical changes. Ratios of myocardial HP metabolites were compared between ES and ED. Segmental analysis was performed on the midcavity short-axis plane. RESULTS: In addition to mechanical changes, metabolic profiles of the heart detected by HP [1-13 C]pyruvate differed between ES and ED. The myocardial signal of [13 C]bicarbonate relative to [1-13 C]lactate was significantly smaller at ED than the ratio at ES (p < .05), particularly in mid-anterior and mid-inferoseptal segments. The distinct metabolic profiles in the myocardium likely reflect the technical aspects of the imaging approach such as the coronary flow in addition to the cyclical changes in metabolism. CONCLUSION: The study demonstrates that metabolic profiles of the heart, measured by HP [1-13 C]pyruvate, are affected by the cardiac cycle in which that the data are acquired.


Assuntos
Coração , Ácido Pirúvico , Isótopos de Carbono , Coração/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Miocárdio
5.
Neurooncol Adv ; 3(1): vdab092, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34355174

RESUMO

BACKGROUND: Glioblastoma remains incurable despite treatment with surgery, radiation therapy, and cytotoxic chemotherapy, prompting the search for a metabolic pathway unique to glioblastoma cells.13C MR spectroscopic imaging with hyperpolarized pyruvate can demonstrate alterations in pyruvate metabolism in these tumors. METHODS: Three patients with diagnostic MRI suggestive of a glioblastoma were scanned at 3 T 1-2 days prior to tumor resection using a 13C/1H dual-frequency RF coil and a 13C/1H-integrated MR protocol, which consists of a series of 1H MR sequences (T2 FLAIR, arterial spin labeling and contrast-enhanced [CE] T1) and 13C spectroscopic imaging with hyperpolarized [1-13C]pyruvate. Dynamic spiral chemical shift imaging was used for 13C data acquisition. Surgical navigation was used to correlate the locations of tissue samples submitted for histology with the changes seen on the diagnostic MR scans and the 13C spectroscopic images. RESULTS: Each tumor was histologically confirmed to be a WHO grade IV glioblastoma with isocitrate dehydrogenase wild type. Total hyperpolarized 13C signals detected near the tumor mass reflected altered tissue perfusion near the tumor. For each tumor, a hyperintense [1-13C]lactate signal was detected both within CE and T2-FLAIR regions on the 1H diagnostic images (P = .008). [13C]bicarbonate signal was maintained or decreased in the lesion but the observation was not significant (P = .3). CONCLUSIONS: Prior to surgical resection, 13C MR spectroscopic imaging with hyperpolarized pyruvate reveals increased lactate production in regions of histologically confirmed glioblastoma.

6.
Magn Reson Med ; 86(1): 157-166, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33547689

RESUMO

PURPOSE: This study aimed to investigate the role of regional f0 inhomogeneity in spiral hyperpolarized 13 C image quality and to develop measures to alleviate these effects. METHODS: Field map correction of hyperpolarized 13 C cardiac imaging using spiral readouts was evaluated in healthy subjects. Spiral readouts with differing duration (26 and 45 ms) but similar resolution were compared with respect to off-resonance performance and image quality. An f0 map-based image correction based on the multifrequency interpolation (MFI) method was implemented and compared to correction using a global frequency shift alone. Estimation of an unknown frequency shift was performed by maximizing a sharpness objective based on the Sobel variance. The apparent full width half at maximum (FWHM) of the myocardial wall on [13 C]bicarbonate was used to estimate blur. RESULTS: Mean myocardial wall FWHM measurements were unchanged with the short readout pre-correction (14.1 ± 2.9 mm) and post-MFI correction (14.1 ± 3.4 mm), but significantly decreased in the long waveform (20.6 ± 6.6 mm uncorrected, 17.7 ± 7.0 corrected, P = .007). Bicarbonate signal-to-noise ratio (SNR) of the images acquired with the long waveform were increased by 1.4 ± 0.3 compared to those acquired with the short waveform (predicted 1.32). Improvement of image quality was observed for all metabolites with f0 correction. CONCLUSIONS: f0 -map correction reduced blur and recovered signal from dropouts, particularly along the posterior myocardial wall. The low image SNR of [13 C]bicarbonate can be compensated with longer duration readouts but at the expense of increased f0 artifacts, which can be partially corrected for with the proposed methods.


Assuntos
Artefatos , Processamento de Imagem Assistida por Computador , Algoritmos , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Razão Sinal-Ruído
7.
Anesth Analg ; 132(4): 930-941, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33093359

RESUMO

BACKGROUND: Coronavirus disease-2019 (COVID-19) is associated with hypercoagulability and increased thrombotic risk in critically ill patients. To our knowledge, no studies have evaluated whether aspirin use is associated with reduced risk of mechanical ventilation, intensive care unit (ICU) admission, and in-hospital mortality. METHODS: A retrospective, observational cohort study of adult patients admitted with COVID-19 to multiple hospitals in the United States between March 2020 and July 2020 was performed. The primary outcome was the need for mechanical ventilation. Secondary outcomes were ICU admission and in-hospital mortality. Adjusted hazard ratios (HRs) for study outcomes were calculated using Cox-proportional hazards models after adjustment for the effects of demographics and comorbid conditions. RESULTS: Four hundred twelve patients were included in the study. Three hundred fourteen patients (76.3%) did not receive aspirin, while 98 patients (23.7%) received aspirin within 24 hours of admission or 7 days before admission. Aspirin use had a crude association with less mechanical ventilation (35.7% aspirin versus 48.4% nonaspirin, P = .03) and ICU admission (38.8% aspirin versus 51.0% nonaspirin, P = .04), but no crude association with in-hospital mortality (26.5% aspirin versus 23.2% nonaspirin, P = .51). After adjusting for 8 confounding variables, aspirin use was independently associated with decreased risk of mechanical ventilation (adjusted HR, 0.56, 95% confidence interval [CI], 0.37-0.85, P = .007), ICU admission (adjusted HR, 0.57, 95% CI, 0.38-0.85, P = .005), and in-hospital mortality (adjusted HR, 0.53, 95% CI, 0.31-0.90, P = .02). There were no differences in major bleeding (P = .69) or overt thrombosis (P = .82) between aspirin users and nonaspirin users. CONCLUSIONS: Aspirin use may be associated with improved outcomes in hospitalized COVID-19 patients. However, a sufficiently powered randomized controlled trial is needed to assess whether a causal relationship exists between aspirin use and reduced lung injury and mortality in COVID-19 patients.


Assuntos
Aspirina/uso terapêutico , COVID-19/terapia , Fibrinolíticos/uso terapêutico , Unidades de Terapia Intensiva , Admissão do Paciente , Inibidores da Agregação Plaquetária/uso terapêutico , Respiração Artificial , Adulto , Idoso , COVID-19/diagnóstico , COVID-19/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
8.
Circ Res ; 127(12): 1568-1570, 2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33054563
9.
Am J Physiol Renal Physiol ; 315(5): F1271-F1282, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30110571

RESUMO

To better understand the role of the inward-rectifying K channel Kir4.1 (KCNJ10) in the distal nephron, we initially studied a global Kir4.1 knockout mouse (gKO), which demonstrated the hypokalemia and hypomagnesemia seen in SeSAME/EAST syndrome and was associated with reduced Na/Cl cotransporter (NCC) expression. Lethality by ~3 wk, however, limits the usefulness of this model, so we developed a kidney-specific Kir4.1 "knockdown" mouse (ksKD) using a cadherin 16 promoter and Cre-loxP methodology. These mice appeared normal and survived to adulthood. Kir4.1 protein expression was decreased ~50% vs. wild-type (WT) mice by immunoblotting, and immunofluorescence showed moderately reduced Kir4.1 staining in distal convoluted tubule that was minimal or absent in connecting tubule and cortical collecting duct. Under control conditions, the ksKD mice showed metabolic alkalosis and relative hypercalcemia but were normokalemic and mildly hypermagnesemic despite decreased NCC expression. In addition, the mice had a severe urinary concentrating defect associated with hypernatremia, enlarged kidneys with tubulocystic dilations, and reduced aquaporin-3 expression. On a K/Mg-free diet for 1 wk, however, ksKD mice showed marked hypokalemia (serum K: 1.5 ± 0.1 vs. 3.0 ± 0.1 mEq/l for WT), which was associated with renal K wasting (transtubular K gradient: 11.4 ± 0.8 vs. 1.6 ± 0.4 in WT). Phosphorylated-NCC expression increased in WT but not ksKD mice on the K/Mg-free diet, suggesting that loss of NCC adaptation underlies the hypokalemia. In conclusion, even modest reduction in Kir4.1 expression results in impaired K conservation, which appears to be mediated by reduced expression of activated NCC.


Assuntos
Néfrons/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/deficiência , Potássio na Dieta/sangue , Reabsorção Renal , Alcalose/sangue , Alcalose/genética , Alcalose/fisiopatologia , Animais , Aquaporina 3/metabolismo , Técnicas de Silenciamento de Genes , Genótipo , Hipercalcemia/sangue , Hipercalcemia/genética , Hipercalcemia/fisiopatologia , Hiperpotassemia/sangue , Hiperpotassemia/genética , Hiperpotassemia/fisiopatologia , Hipernatremia/sangue , Hipernatremia/genética , Hipernatremia/fisiopatologia , Capacidade de Concentração Renal , Camundongos Endogâmicos C57BL , Camundongos Knockout , Néfrons/fisiopatologia , Fenótipo , Fosforilação , Canais de Potássio Corretores do Fluxo de Internalização/genética , Membro 3 da Família 12 de Carreador de Soluto/metabolismo
10.
Arch. cardiol. Méx ; 87(1): 5-12, ene.-mar. 2017. tab
Artigo em Espanhol | LILACS | ID: biblio-887488

RESUMO

Resumen: Objetivo: La fibrilación auricular (FA) es una de las arritmias más comunes, y su prevalencia aumenta con la edad. Se asocia con alto riesgo de embolia cerebral. La prevención de dichas tromboembolias se realiza mediante anticoagulantes orales, que en nuestro país parecen estar subutilizados. El Registro CARMEN-AF tiene como objetivo primario determinar cuál es el estado actual de la tromboprofilaxis de la FA no valvular en México. Como objetivo secundario pretende conocer la morbimortalidad asociada a la FA no valvular en por lo menos un año de seguimiento. Métodos: El Registro CARMEN-AF es un estudio observacional, longitudinal, multicéntrico y nacional sobre el empleo de los anticoagulantes orales en pacientes con FA no-valvular que pretende la inclusión de pacientes mayores de 18 años de edad diagnosticados con FA no valvular durante los últimos 6 meses y con al menos un factor de riesgo para desarrollar una tromboembolia de acuerdo con la escala de CHA2DS2-Vasc. Serán recolectados datos demográficos y clínicos en las visitas clínicas habituales a lo largo de un seguimiento de 2 años. El reclutamiento comenzó el 19 de septiembre de 2014 y se prevé la inclusión del último paciente el 18 de septiembre de 2016. Se estima la inclusión de 1,200 pacientes dada la incidencia de FA reportada a nivel mundial y tomando en consideración la población mexicana total. Conclusiones: El registro de FA y riesgo embólico en México (CARMEN-AF) permitirá conocer el estado actual de la tromboprofilaxis en pacientes con FA no valvular y permitirá obtener una panorámica del cumplimiento de las guías nacionales e internacionales de práctica clínica en esta materia.


Abstract: Objective: Atrial fibrillation (AF) is one of the most common arrhythmias, and its prevalence increase with age. It is associated with high risk of stroke. The prevention of such thromboembolism is done with oral anticoagulants, which in our country seem to be underused. CARMEN-AF registry aims primarily to determine the current status of thromboprophylaxis of non-valvular AF in Mexico. A secondary objective is to know the morbidity and mortality associated with non-valvular AF in at least one year of follow-up. Methods: CARMEN-AF registry is an observational, longitudinal, multicenter, and national survey about the use of oral anticoagulants in patients with non-valvular AF. Patients 18 years old or older, diagnosed with AF during the last 6 months, and with at least one risk factor of thromboembolism based in the CHA2DS2-Vasc score are being selected. Demographic and clinical data will be collected during the visits to their usual clinic with a follow-up of 2 years. The recruitment began on September 19, 2014, and the inclusion of the last patient is expected on September 18, 2016. According to the reported incidence of AF globally and taking into account the total Mexican population, the inclusion of 1,200 patients is estimated. Conclusions: The Atrial Fibrillation and Embolic Risk Registry (CARMEN-AF) will reveal the current status of thromboprophylaxis in patients with non-valvular AF, and will allow to get an overview of the national and international clinical practice guidelines accomplishment in this area.


Assuntos
Humanos , Fibrilação Atrial/complicações , Tromboembolia/etiologia , Tromboembolia/epidemiologia , Sistema de Registros , Projetos de Pesquisa , Tromboembolia/prevenção & controle , Administração Oral , Fatores de Risco , Estudos Longitudinais , México , Anticoagulantes/administração & dosagem
11.
Arch Cardiol Mex ; 87(1): 5-12, 2017.
Artigo em Espanhol | MEDLINE | ID: mdl-27986560

RESUMO

OBJECTIVE: Atrial fibrillation (AF) is one of the most common arrhythmias, and its prevalence increase with age. It is associated with high risk of stroke. The prevention of such thromboembolism is done with oral anticoagulants, which in our country seem to be underused. CARMEN-AF registry aims primarily to determine the current status of thromboprophylaxis of non-valvular AF in Mexico. A secondary objective is to know the morbidity and mortality associated with non-valvular AF in at least one year of follow-up. METHODS: CARMEN-AF registry is an observational, longitudinal, multicenter, and national survey about the use of oral anticoagulants in patients with non-valvular AF. Patients 18years old or older, diagnosed with AF during the last 6months, and with at least one risk factor of thromboembolism based in the CHA2DS2-Vasc score are being selected. Demographic and clinical data will be collected during the visits to their usual clinic with a follow-up of 2years. The recruitment began on September 19, 2014, and the inclusion of the last patient is expected on September 18, 2016. According to the reported incidence of AF globally and taking into account the total Mexican population, the inclusion of 1,200 patients is estimated. CONCLUSIONS: The Atrial Fibrillation and Embolic Risk Registry (CARMEN-AF) will reveal the current status of thromboprophylaxis in patients with non-valvular AF, and will allow to get an overview of the national and international clinical practice guidelines accomplishment in this area.


Assuntos
Fibrilação Atrial/complicações , Sistema de Registros , Tromboembolia/epidemiologia , Tromboembolia/etiologia , Administração Oral , Anticoagulantes/administração & dosagem , Humanos , Estudos Longitudinais , México , Projetos de Pesquisa , Fatores de Risco , Tromboembolia/prevenção & controle
12.
PLoS One ; 11(7): e0159989, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27459203

RESUMO

The mitochondrial unfolded protein response (UPRmt) is a surveillance pathway that defends proteostasis in the "powerhouse" of the cell. Activation of the UPRmt protects against stresses imposed by reactive oxygen species, respiratory chain deficits, and pathologic bacteria. Consistent with the UPRmt's role in adaption, we found that either its pharmacological or genetic activation by ethidium bromide (EtBr) or RNAi of the mitochondrial AAA-protease spg-7 was sufficient to reduce death in an anoxia-based Caenorhabditis elegans model of ischemia-reperfusion injury. The UPRmt-specific transcription factor atfs-1 was necessary for protection and atfs-1 gain-of-function (gf) mutants were endogenously protected from both death and dysfunction. Neurons exhibited less axonal degeneration following non-lethal anoxia-reperfusion (A-R) when the UPRmt was pre-activated, and consistent with the concept of mitochondrial stress leading to cell non-autonomous (ie. "remote") effects, we found that restricted activation of the UPRmt in neurons decreased A-R death. However, expression of the atfs-1(gf) mutant in neurons, which resulted in a robust activation of a neuronal UPRmt, did not upregulate the UPRmt in distal tissues, nor did it protect the worms from A-R toxicity. These findings suggest that remote signaling requires additional component(s) acting downstream of de facto mitochondrial stress.


Assuntos
Caenorhabditis elegans/metabolismo , Hipóxia/metabolismo , Metaloendopeptidases/metabolismo , Interferência de RNA , Traumatismo por Reperfusão/metabolismo , Resposta a Proteínas não Dobradas , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Metaloendopeptidases/genética , Neurônios/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
Rev. mex. cardiol ; 24(1): 28-28, ene.-mar. 2013.
Artigo em Espanhol | LILACS-Express | LILACS | ID: lil-714443
14.
Gut ; 62(11): 1556-65, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23263249

RESUMO

OBJECTIVE: Through genome-wide association scans and meta-analyses thereof, over 70 genetic loci (Crohn's disease (CD) single nucleotide polymorphisms (SNPs)) are significantly associated with CD. We aimed to investigate the influence of CD-SNPs and basic patient characteristics on CD clinical course, and develop statistical models to predict CD clinical course. DESIGN: This retrospective study included 1528 patients with CD with more than 10 years of follow-up from eight European referral hospitals. CD outcomes of interest were ileal (L1), colonic (L2) and ileocolonic disease location (L3); stenosing (B2) or penetrating behaviour (B3); perianal disease; extraintestinal manifestations; and bowel resection. A complicated disease course was defined as stenosing or penetrating behaviour, perianal disease and/or bowel resection. Association between CD-SNPs or patient characteristics and specified outcomes was studied. RESULTS: Several CD-SNPs and clinical characteristics were statistically associated with outcomes of interest. The NOD2 gene was the most important genetic factor, being an independent predictive factor for ileal location (p=2.02 × 10(-06), OR=1.90), stenosing (p=3.16 × 10(-06), OR=1.82) and penetrating (p=1.26 × 10(-02), OR=1.25) CD behaviours, and need for surgery (p=2.28 × e-05, OR=1.73), and as such was also the strongest factor associated with a complicated disease course (p=6.86 × 10(-06), OR=2.96). Immunomodulator (azathioprine/6-mercaptopurine and methotrexate) use within 3 years after diagnosis led to a reduction in bowel stenoses (p=1.48 × 10(-06), OR=0.35) and surgical rate (p=1.71 × 10(-07), OR=0.34). Association between each outcome and genetic scores, created using significant SNPs in the univariate analysis, revealed large differences in the probability of developing fistulising disease (IL23R, LOC441108, PRDM1, NOD2; p=9.64e-4, HR=1.43), need for surgery (IRGM, TNFSF15, C13ORF31, NOD2; p=7.12 × 10(-03), HR=1.35), and stenosing disease (NOD2, JAK2, ATG16L1; p=3.01 × 10(-02), HR=1.29) among patients with low and high score. CONCLUSIONS: This large multicentre cohort study has found several genetic and clinical factors influencing the clinical course of CD. NOD2 and early immunomodulator use are the clinically most meaningful predictors for its clinical course.


Assuntos
Doença de Crohn/genética , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Colite/epidemiologia , Colite/genética , Doença de Crohn/complicações , Doença de Crohn/epidemiologia , Doença de Crohn/terapia , Progressão da Doença , Europa (Continente)/epidemiologia , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem/métodos , Humanos , Ileíte/epidemiologia , Ileíte/genética , Imunossupressores/uso terapêutico , Obstrução Intestinal/epidemiologia , Obstrução Intestinal/etiologia , Obstrução Intestinal/genética , Obstrução Intestinal/prevenção & controle , Janus Quinase 2/genética , Masculino , Modelos Estatísticos , Proteína Adaptadora de Sinalização NOD2/genética , Fenótipo , Prognóstico , Estudos Retrospectivos , Adulto Jovem
15.
J Am Chem Soc ; 134(48): 19746-57, 2012 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-23167247

RESUMO

The apoprotein of Pseudomonas aeruginosa azurin binds iron(II) to give a 1:1 complex, which has been characterized by electronic absorption, Mössbauer, and NMR spectroscopies, as well as X-ray crystallography and quantum-chemical computations. Despite potential competition by water and other coordinating residues, iron(II) binds tightly to the low-coordinate site. The iron(II) complex does not react with chemical redox agents to undergo oxidation or reduction. Spectroscopically calibrated quantum-chemical computations show that the complex has high-spin iron(II) in a pseudotetrahedral coordination environment, which features interactions with side chains of two histidines and a cysteine as well as the C═O of Gly45. In the (5)A(1) ground state, the d(z(2)) orbital is doubly occupied. Mutation of Met121 to Ala leaves the metal site in a similar environment but creates a pocket for reversible binding of small anions to the iron(II) center. Specifically, azide forms a high-spin iron(II) complex and cyanide forms a low-spin iron(II) complex.


Assuntos
Azurina/química , Ferro/química , Ferroproteínas não Heme/química , Teoria Quântica , Azidas/química , Sítios de Ligação , Complexos de Coordenação/química , Cristalografia por Raios X , Cianetos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oxirredução
16.
Neurochem Res ; 37(11): 2496-512, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22717696

RESUMO

Norepinephrine (NE) is a neuromodulator that in multiple ways regulates the activity of neuronal and non-neuronal cells. NE participates in the rapid modulation of cortical circuits and cellular energy metabolism, and on a slower time scale in neuroplasticity and inflammation. Of the multiple sources of NE in the brain, the locus coeruleus (LC) plays a major role in noradrenergic signaling. Processes from the LC primarily release NE over widespread brain regions via non-junctional varicosities. We here review the actions of NE in astrocytes, microglial cells, and neurons based on the idea that the overarching effect of signaling from the LC is to maximize brain power, which is accomplished via an orchestrated cellular response involving most, if not all cell types in CNS.


Assuntos
Sistema Nervoso Central/fisiologia , Norepinefrina/fisiologia , Adaptação Fisiológica , Animais , Astrócitos/fisiologia , Humanos , Microglia/fisiologia
17.
Pharmacogn Mag ; 7(27): 234-42, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21969795

RESUMO

BACKGROUND: Aconitum napellus (Acn) is used topically to relieve pain, itching and inflammation, and internally to reduce febrile states, among others. Any circadian time-related consequences of Acn administration are unknown. The objective of this study was to explore the effects of two doses of Acn on body temperature (BT) of mice treated at six different times over 24 hours. MATERIALS AND METHODS: BALB/c female mice were housed in six chambers (six mice each) with air temperature 24 ± 3°C, humidity 60 ± 4%, and a 12-hours light (L)/12-hours dark cycle, but with L-onset staggered by 4 hours between chambers so that study at one external test time resulted in six test times (02, 06, 10, 14, 18 and 22 hours [h] after light onset). Rectal temperature (RT; in °C) was measured at baseline (B) and 1 hour after oral treatment with placebo (P) or two doses of Acn (6C and 30C, two studies each) in six studies over an 8 day span. The difference in RT for each mouse from the respective B + P timepoint mean RT was computed following each Acn treatment, and data from each of the six studies (original RT and difference from B + P) were analyzed for time-effect by analysis of variance (ANOVA) and for circadian rhythm by 24-hour cosine fitting. RESULTS: A CIRCADIAN RHYTHM IN RT WAS FOUND AT B AND AFTER P (MEAN: 35.58°C vs. 35.69°C; peak: 15:31 h vs. 15:40 h) and after each Acn dose (30C or 6C). Acn induced hyperthermia and the overall change in BT was rhythmically significant for each dose (mean = +1.95°C vs. +1.70°C), with greatest hyperthermia observed during the L-span for each dose (peak = 08:56 h vs. 05:17 h). CONCLUSION: Acn administered around the clock induced hyperthermia overall and in a time-dependent manner, with greatest effects during the resting (L) span. Thus, time of day may significantly impact the outcome of Acn and other homeopathic treatments and should be considered in determining optimal dosing and treatment time(s) in order to increase the desired outcome and decrease undesired effects.

18.
Obesity (Silver Spring) ; 19(4): 729-35, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20829804

RESUMO

We examined the influences of obesity and diabetes on endothelium-dependent and -independent vasodilation, inflammatory cytokines, and growth factors. We included 258 subjects, age 21-80 years in four groups matched for age and gender: 40 healthy nonobese (BMI <30 kg·m(-2)) nondiabetic subjects, 76 nonobese diabetic patients, 37 obese (BMI >30) nondiabetic subjects, and 105 obese (BMI >30) diabetic patients. The flow-mediated dilation (FMD, endothelium-dependent) and nitroglycerin-induced dilation (NID, endothelium-independent) in the brachial artery, the vascular reactivity at the forearm skin and serum growth factors and inflammatory cytokines were measured. FMD was reduced in the nonobese diabetic patients, obese nondiabetic controls, and obese diabetic patients (P < 0.0001). NID was different among all four groups, being highest in the obese nondiabetic subjects and lowest in the obese diabetic patients (P < 0.0001). The resting skin forearm blood flow was reduced in the obese nondiabetic subjects (P < 0.01). Vascular endothelial growth factor (VEGF) was higher in the obese nondiabetic subjects (P < 0.05), tumor necrosis factor-α was higher in the obese diabetic patients (P < 0.0001) and C-reactive protein was higher in both the obese nondiabetic and diabetic subjects (P < 0.0001). Soluble intercellular adhesion molecule-1 was elevated in the two diabetic groups and the obese nondiabetic subjects (P < 0.05). We conclude that diabetes and obesity affect equally the endothelial cell function but the smooth muscle cell function is affected only by diabetes. In addition, the above findings may be related to differences that were observed in the growth factors and inflammatory cytokines.


Assuntos
Artéria Braquial/metabolismo , Diabetes Mellitus/fisiopatologia , Obesidade/fisiopatologia , Fatores de Crescimento do Endotélio Vascular/sangue , Vasodilatação , Adulto , Idoso , Idoso de 80 Anos ou mais , Composição Corporal , Índice de Massa Corporal , Proteína C-Reativa/análise , Estudos Transversais , Feminino , Antebraço/anatomia & histologia , Humanos , Molécula 1 de Adesão Intercelular/sangue , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Pele/irrigação sanguínea , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
20.
Eur J Cancer ; 44(6): 774-80, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18342503

RESUMO

Despite declining incidence rates, gastric cancer (GC) is a major cause of death worldwide. E-Cadherin is an adhesion molecule that is thought to be involved in GC. Germline mutations in the E-Cadherin gene (CDH1) have been identified in hereditary diffuse GC. Also, a promoter polymorphism at position -160 C/A has been suggested to lead to transcriptional down regulation and has been shown to affect GC risk in some studies. However, very little information exists on the GC risk association of other CDH1 polymorphisms and it is unclear whether any associations may be different by GC anatomical sites or histological types. Thus, a case-control study (cases=245/controls=950) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort was conducted to assess the GC risk association of eight CDH1 gene polymorphisms. None of the CDH1 polymorphisms or haplotypes analysed were associated with GC risk and no differences of effect were observed by Helicobacter pylori infection status. However, three CDH1 polymorphisms in the same haplotype block, including the CDH1-160C/A, interacted with smoking to increase GC risk in smokers but not in never smokers. These findings should be confirmed in larger independent studies.


Assuntos
Caderinas/genética , Infecções por Helicobacter/complicações , Helicobacter pylori , Polimorfismo Genético/genética , Fumar/efeitos adversos , Neoplasias Gástricas/etiologia , Antígenos CD , Métodos Epidemiológicos , Europa (Continente) , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...