EDTA as a chelating agent in quantitative 1H-NMR of biologically important ions.

Biologically important ions such as Ca, K, Mg, Fe, and Zn play major roles in numerous biological processes, and their homeostatic balance is necessary for the maintenance of cellular activities. Sudden and severe loss in homeostasis of just one biologically important ion can cause a cascade of negative effects. The ability to quickly, accurately, and reliably quantify biologically important ions in samples of human bio-fluids is something that has been sorely lacking within the field of metabolomics. 1H-NMR spectra. The foundation of our investigation was the a-priori knowledge that free ethylenediaminetetraacetic acid (EDTA) produces two clear single peaks on 1H-NMR spectra, and that EDTA chelated to different ions produces unique 1H-NMR spectral patterns due to 3D conformational changes in the chemical structure of chelated-EDTA and varying degrees of electronegativity. The aim of this study was to develop and test a 1H-NMR-based method, with application specifically to the field of metabolomics, to quantify biologically important ions within the physiological pH range of 6.50-7.50 using EDTA as a chelating agent. Our method produced linear, accurate, precise, and repeatable results for Ca, Mg, and Zn; however, K and Fe did not chelate with EDTA.

Dynamic metabolomic responses of Escherichia coli to nicotine stress.

Previously, we reported the metabolic responses of Pseudomonas sp. strain HF-1, a nicotine-degrading bacterium, to nicotine stress. However, the metabolic effects of nicotine on non-nicotine-degrading bacteria that dominate the environment are still unclear. Here, we have used nuclear magnetic resonance based metabolomics in combination with multivariate data analysis methods to comprehensively analyze the metabolic changes in nicotine-treated Escherichia coli. Our results showed that nicotine caused the changes of energy-related metabolism that we believe are due to enhanced glycolysis and mixed acid fermentation as well as inhibited tricarboxylic acid cycle activity. Furthermore, nicotine resulted in the alteration of choline metabolism with a decreased synthesis of betaine but an increased production of dimethylamine. Moreover, nicotine caused a decrease in amino acid concentration and an alteration of nucleotide synthesis. We hypothesize that these changes caused the decrease in bacterial cell density observed in the experiment. These findings provide a comprehensive insight into the metabolic response of E. coli to nicotine stress. Our study highlights the value of metabolomics in elucidating the metabolic mechanisms of nicotine action.

Neuroimaging findings in primary insomnia.

State-of-the-art neuroimaging techniques have accelerated progress in the study and understanding of sleep in humans. Neuroimaging studies in primary insomnia remain relatively few, considering the important prevalence of this disorder in the general population. This review examines the contribution of functional and structural neuroimaging to our current understanding of primary insomnia. Functional studies during sleep provided support for the hyperarousal theory of insomnia. Functional neuroimaging also revealed abnormalities in cognitive and emotional processing in primary insomnia. Results from structural studies suggest neuroanatomical alterations in primary insomnia, mostly in the hippocampus, anterior cingulate cortex and orbitofrontal cortex. However, these results are not well replicated across studies. A few magnetic resonance spectroscopy studies revealed abnormalities in neurotransmitter concentrations and bioenergetics in primary insomnia. The inconsistencies among neuroimaging findings on insomnia are likely due to clinical heterogeneity, differences in imaging and overall diversity of techniques and designs employed. Larger samples, replication, as well as innovative methodologies are necessary for the progression of this perplexing, yet promising area of research.

Early metabolic response after resistance exercise with blood flow restriction in well-trained men: a metabolomics approach.

The present study aimed to compare the early metabolic response between high-load resistance exercise (HL-RE) and low-load resistance exercise with blood flow restriction (LL-BFR). Nine young, well-trained men participated in a randomized crossover design in which each subject completed LL-BFR, HL-RE, or condition control (no exercise) with a 1-week interval between them. Blood samples were taken immediately before and 5 min after the exercise sessions. Nuclear magnetic resonance spectroscopy identified and quantified 48 metabolites, 6 of which presented significant changes among the exercise protocols. The HL-RE promoted a higher increase in pyruvate, lactate, and alanine compared with the LL-BFR and the control. HL-RE and LL-BFR promoted a higher increase in succinate compared with the control; however, there was no difference between HL-RE and LL-BFR. Also, while there was no difference in acetoacetate between HL-RE and LL-BFR, a greater decrease was observed in both compared with the control. Finally, LL-BFR promoted a greater decrease in choline compared with the control. In conclusion, this study provides by metabolomics a new insight in metabolic response between LL-BFR and HL-RE by demonstrating a distinct response to some metabolites that are not commonly analyzed.

[Evaluation of cardiac MRI in the follow up assessment of patients with pulmonary arterial hypertension]. / Évaluation de l'IRM cardiaque dans le suivi des patients ayant une hypertension artérielle pulmonaire (EVITA). IRM cardiaque dans le suivi de l'hypertension artérielle pulmonaire.

Haemodynamic follow up in pulmonary arterial hypertension (PAH) is currently based on right heart catheterisation (RHC). The primary objective of the EVITA study is to compare the use of cardiac magnetic resonance imaging (cMRI) with RHC in the identification of an unfavourable hemodynamic status. The secondary objectives are to determine the role of cMRI in the follow up process. Patients will undergo at diagnosis and at follow up visits both RHC and cMRI. Patients will be followed and treated according to the current guidelines. The primary endpoint will be an unfavourable haemodynamic status defined by cardiac index<2.5L/min/m2 or a right atrial pressure≥8mm Hg measured with RHC compared with a cardiac index<2.5L/min/m2 or right ventricle ejection fraction<35% or an absolute decrease of 10% from the previous measurement with cMRI. Exact values of sensitivity, specificity and 95% confidence intervals will be computed. A population of 180 subjects will have a power of 90% with an α risk of 5%. Univariate and multivariate Cox analysis will allow answering to the secondary objectives. We expect to demonstrate that cMRI could be partly used instead of RHC in the follow up of patients with PAH.

The impact of moderate altitude on exercise metabolism in recreational sportsmen: a nuclear magnetic resonance metabolomic approach.

Although it is known that altitude impairs performance in endurance sports, there is no consensus on the involvement of energy substrates in this process. The objective of the present study was to determine whether the metabolomic pathways used during endurance exercise differ according to whether the effort is performed at sea level or at moderate altitude (at the same exercise intensity, using proton nuclear magnetic resonance, 1H NMR). Twenty subjects performed two 60-min endurance exercise tests at sea level and at 2150 m at identical relative intensity on a cycle ergometer. Blood plasma was obtained from venous blood samples drawn before and after exercise. 1H NMR spectral analysis was then performed on the plasma samples. A multivariate statistical technique was applied to the NMR data. The respective relative intensities of the sea level and altitude endurance tests were essentially the same when expressed as a percentage of the maximal oxygen uptake measured during the corresponding incremental maximal exercise test. Lipid use was similar at sea level and at altitude. In the plasma, levels of glucose, glutamine, alanine, and branched-chain amino acids had decreased after exercise at altitude but not after exercise at sea level. The decrease in plasma glucose and free amino acid levels observed after exercise at altitude indicated that increased involvement of the protein pathway was necessary but not sufficient for the maintenance of glycaemia. Metabolomics is a powerful means of gaining insight into the metabolic changes induced by exercise at altitude.

[Ecchymosis as the presenting manifestation of Wilson disease: A case report]. / Ecchymoses diffuses révélant une maladie de Wilson : à propos d'un cas.

INTRODUCTION: The presence of a psychiatric disorder during the course of an organic disease is a common cause of delayed diagnosis. CASE REPORT: We report a 16-year-old girl who was admitted with thrombocytopenia and had a two-year history of neuropsychiatric disorder which was attributed to a difficult family situation. Neurological examination showed a frontal lobe disorder and extrapyramidal manifestations. The thrombocytopenia was attributed to liver cirrhosis. These neurological and hepatic injuries were consistent with a metabolic disease, most likely Wilson disease. This was supported by the presence of a corneal Kayser-Fleischer ring and a decreased ceruloplasmin concentration. An urgent liver transplantation was required due to worsening neurological symptoms. CONCLUSION: Wilson disease is a rare genetic disease caused by copper toxicity. It is characterized by combined hepatic and neurologic damage to varying degrees and can develop at any age. Urgent treatment is required, but the diagnosis may be delayed by prevailing psychiatric symptoms.

Pancreatic lipid content is not associated with beta cell dysfunction in youth-onset type 2 diabetes.

OBJECTIVE: To determine whether pancreatic lipid content is associated with type 2 diabetes and beta cell function in Indigenous and Caucasian adolescents. METHODS: This was a cross-sectional study comparing (1)H-magnetic resonance spectroscopy-derived pancreatic triglyceride content in adolescents 13 to 18 years of age with type 2 diabetes (n=20) and body mass index-matched normoglycemic controls (n=34). Beta cell function was measured by the acute insulin response and disposition index derived from intravenous glucose tolerance tests. RESULTS: Pancreatic lipid content was not significantly different in youth with type 2 diabetes and their normoglycemic body mass index-matched peers (2.41 [95% CI: 0.63, 5.60] vs. 1.22 [0.08, 5.93]; p=0.27). Pancreatic triglyceride levels were not associated with measures of beta cell function in the cohort. In subgroup analyses, pancreatic lipid content was ∼4-fold higher in youth with type 2 diabetes who were carriers of the G319S mutation in the HNF-1alpha gene (7.45 [2.85, 26.8] vs. 2.20 [0.350, 3.30] % Fat to Water Ratio F/W; p=0.032). CONCLUSIONS: Pancreatic lipid content is not elevated in Indigenous or Caucasian youth with type 2 diabetes compared to normoglycemic youth, nor is it associated with beta cell function. The presence of the G319S mutation in the HNF-1alpha gene in Indigenous youth with type 2 diabetes is associated with higher pancreatic lipid content. Further research is needed to understand the mechanisms that explain beta cell failure in overweight youth with type 2 diabetes.

[Rare case of bilateral pulmonary agenesis and prenatal diagnosis]. / Diagnostic anténatal d'une agénésie pulmonaire bilatérale : une observation exceptionnelle.

Bilateral pulmonary agenesis (BPA) is a rare congenital lung malformation. The prognosis is severe as it is incompatible with extra-uterine life. Although multiple prenatal imaging modalities are developed, the prenatal diagnosis of BPA remains problematic. We report a case of BPA observed in our unity and for which the diagnosis was not clearly identified during the evaluation. This report illustrates the need to consider all the imaging aspects and particularly during US examination suspecting BPA.

Effect of ivabradine on left ventricular remodelling after reperfused myocardial infarction: A pilot study.

BACKGROUND: Heart rate is a major determinant of myocardial oxygen demand; in ST-segment elevation myocardial infarction (STEMI), patients treated with primary percutaneous intervention (PPCI), heart rate at discharge correlates with mortality. Ivabradine is a pure heart rate-reducing agent that has no effect on blood pressure and contractility, and can reverse left ventricular (LV) remodelling in patients with heart failure. AIMS: To evaluate whether ivabradine, when added to current guideline-based therapy, improves LV remodelling in STEMI patients treated with PPCI. METHODS: This paired-cohort study included 124 patients between June 2011 and July 2012. Ivabradine (5mg twice daily) was given promptly after PPCI, along with beta-blockers, to obtain a heart rate<60 beats per minute (ivabradine group). This group was matched with STEMI patients treated in line with current guidelines, including beta-blockers (bisoprolol), according to age, sex, infarct-related coronary artery, ischaemia time and infarct size determined by initial cardiac magnetic resonance imaging (CMR) (control group). Statistical analyses were performed according to an intention-to-continue treatment principle. CMR data at 3 months were available for 122 patients. RESULTS: Heart rate was lower in the ivabradine group than in the control group during the initial CMR (P=0.02) and the follow-up CMR (P=0.006). At the follow-up CMR, there was a smaller increase in LV end-diastolic volume index in the ivabradine group than in the control group (P=0.04). LV end-systolic volume index remained unchanged in the ivabradine group, but increased in the control group (P=0.01). There was a significant improvement in LV ejection fraction in the ivabradine group compared with in the control group (P=0.04). CONCLUSIONS: In successfully reperfused STEMI patients, ivabradine may improve LV remodelling when added to current guideline-based therapy.

[Nuclear magnetic resonance based metabolic phenotyping for patient evaluations in operating rooms and intensive care units]. / Phénotypage métabolique par résonance magnétique nucléaire pour l'évaluation périopératoire et en réanimation.

Metabolic phenotyping consists in the identification of subtle and coordinated metabolic variations associated with various pathophysiological stimuli. Different analytical methods, such as nuclear magnetic resonance, allow the simultaneous quantification of a large number of metabolites. Statistical analyses of these spectra thus lead to the discrimination between samples and the identification of a metabolic phenotype corresponding to the effect under study. This approach allows the extraction of candidate biomarkers and the recovery of perturbed metabolic networks, driving to the generation of biochemical hypotheses (pathophysiological mechanisms, diagnostic tests, therapeutic targets…). Metabolic phenotyping could be useful in anaesthesiology and intensive care medicine for the evaluation, monitoring or diagnosis of life-threatening situations, to optimise patient managements. This review introduces the physical and statistical fundamentals of NMR-based metabolic phenotyping, describes the work already achieved by this approach in anaesthesiology and intensive care medicine. Finally, potential areas of interest are discussed for the perioperative and intensive management of patients, from newborns to adults.

Lesiones medulares crónicas: Recuperación de las funciones medulares después de la corpectomía. Estudio preliminar / Chronic spinal cord injuries: Recovery of the spinal cord functions. A preliminary study / Lésions médullaires après la corpectomie: Etude préliminaire.

Se realizó el estudio de 6 pacientes con lesiones medulares de entre 2 y 10 años de evolución con compresión de la región anterior de la médula determinada mediante resonancia magnética nuclear. A estos pacientes se les efectuó la descompresión medular mediante la corpectomía transpedicular con fijación sublaminar de columna por la técnica de Luque. Se evalúan clínicamente diferentes aspectos de la función medular, antes y 6 meses después de la intervención. Los pacientes no presentaron mejorías significativas a los 6 meses de intervenidos, a excepción de uno que recuperó parte importante de las funciones vesicales. Se puntualiza la necesidad de realizar estudios con una mayor cantidad de pacientes y la inclusión de un grupo control.

On a étudié 6 patients avec lésions médullaires entre 2 et 10 ans d'évolution avec compression de la régionn antérieure de la moelle déterminée par la résonance magnétique nucléaire. On a réalisé la décompression médullaire au moyen de la corpectomie transpedicullaire avec fixation sous-laminaire de colonne par la technique de Luque. On évalue cliniquement les différents aspects de la fonction médullaire avant et 6 mois après l'intervention. Les patients n'ont pas présenté amélioration significative après six mois de chirurgie. excepté un qui a récupéré une partie importante des fonctions vésicales. On remarque la nécessité de réaliser des études avec une plus grande quantité de patients et l'inclusion d'un groupe contrôle.