Fasting upregulates the monocarboxylate transporter MCT1 at the rat blood-brain barrier through PPAR δ activation.

BACKGROUND: The blood-brain barrier (BBB) is pivotal for the maintenance of brain homeostasis and it strictly regulates the cerebral transport of a wide range of endogenous compounds and drugs. While fasting is increasingly recognized as a potential therapeutic intervention in neurology and psychiatry, its impact upon the BBB has not been studied. This study was designed to assess the global impact of fasting upon the repertoire of BBB transporters. METHODS: We used a combination of in vivo and in vitro experiments to assess the response of the brain endothelium in male rats that were fed ad libitum or fasted for one to three days. Brain endothelial cells were acutely purified and transcriptionaly profiled using RNA-Seq. Isolated brain microvessels were used to assess the protein expression of selected BBB transporters through western blot. The molecular mechanisms involved in the adaptation to fasting were investigated in primary cultured rat brain endothelial cells. MCT1 activity was probed by in situ brain perfusion. RESULTS: Fasting did not change the expression of the main drug efflux ATP-binding cassette transporters or P-glycoprotein activity at the BBB but modulated a restrictive set of solute carrier transporters. These included the ketone bodies transporter MCT1, which is pivotal for the brain adaptation to fasting. Our findings in vivo suggested that PPAR δ, a major lipid sensor, was selectively activated in brain endothelial cells in response to fasting. This was confirmed in vitro where pharmacological agonists and free fatty acids selectively activated PPAR δ, resulting in the upregulation of MCT1 expression. Moreover, dosing rats with a specific PPAR δ antagonist blocked the upregulation of MCT1 expression and activity induced by fasting. CONCLUSIONS: Altogether, our study shows that fasting affects a selected set of BBB transporters which does not include the main drug efflux transporters. Moreover, we describe a previously unknown selective adaptive response of the brain vasculature to fasting which involves PPAR δ and is responsible for the up-regulation of MCT1 expression and activity. Our study opens new perspectives for the metabolic manipulation of the BBB in the healthy or diseased brain.

Analytical performance of Abbott C-16000 analyser haemolysis index and its potential use in measuring plasma cell-free haemoglobin.

Purpose: Measurement of the haemolysis index (HI) is usually performed in clinical chemistry laboratories in order to inform about whether biological analyses are influenced by in vivo or in vitro haemolysis of the specimen. Our aim was to evaluate the analytical performance of Abbott C-16000 analyser HI measurement in order to determine whether this could be used to reliably measure cell-free haemoglobin (fHB) in plasma samples. Methods: The repeatability, reproducibility, lower limit of detection (LLOD) and lower limit of quantification (LLOQ) of C-16000 HI measurement were determined as well as the potential interference of bilirubin, triglycerides and myoglobin. C-16000 HI values of biological samples with various ranges of fHB were compared to those measured using the established reference method, second-derivate spectroscopy. Results: Results: C-16000 HI determination showed excellent linear correlation with the reference method (y = 1.0043x ­ 1.248, R² = 0.998), a broad analytical measurement range (400-20,000 mg/L; y = 0.9904x + 72.972, R² = 0.999), clinically relevant LLOD (56 mg/L) and LLOQ (84 mg/L), good repeatability (coefficient of variation (CV) = 1-15%) and good reproducibility (CV = 5-7%). No interference was observed with myoglobin at concentrations as high as 35,447 mg/L, unconjugated and conjugated bilirubin (at concentrations up to 500 mg/L and 375 mg/L, respectively) or triglycerides up to 6.8 mmol/L. However, a significant underestimation of fHB concentrations was observed at higher triglyceride levels. Conclusion: This study demonstrates that Abbott C-16000 analyser HI is reliable and accurately measures plasma fHB concentrations under pathophysiological conditions except when there are high blood concentrations of triglycerides.

[Detection and identification of urinary crystals using an automated urine particle analyzer coupled with a digital particle imaging device]. / Détection et identification de cristaux dans les urines à l'aide d'un analyseur de cytologie urinaire couplé à un dispositif d'imagerie numérique.

Polarized light microscopy (POM) remains the gold standard for crystalluria analysis. However, such method is time consuming and requires well-trained staff. Here, to address this issue, we tested the Sysmex UF-4000 analyzer coupled to a UD10 module as an automated flow cytometry-digital particle imaging workflow to assess (i) the ability of the system to detect and identify the crystals species and (ii) the quality of the images provided by the UD-10 module (n = 40) for each urine sample analyzed. First, systematic analysis of 76 samples by POM and the UF-4000/UD-10 analyzer showed that only attentive examination of the 40 photos was able to confidently detect crystalluria-positive samples with no misses and thus serve to discriminate positive-test crystalluria from negative-test crystalluria. These first results were confirmed by sensitivity analysis and the negative predictive value calculated on 200 samples for the results provided by the UF-4000 (39% and 46%) and after examination of the 40 UD-10 photos (100% for the both values). Digital images can therefore serve to screen crystalluria without missing crystals. A part of samples were treated by POM whereas it was not necessary (positive predictive value: 78%). Finally, we compared the crystal identification performances of the Sysmex UF4000/UD10 workflow and the 'gold standard' POM method on 131 urine samples containing crystals. Only calcium oxalate dihydrate crystals were identified by the Sysmex UF-4000. A close examination of the digital photographs enabled exact identification of crystals in 84.7% of the samples, suggesting however that POM is still require as soon as crystals are observed on the photographs. We conclude that a SYSMEX UF-4000 coupled with a UD-10 module can be used in practice with close examination of the photographs to discriminate positive crystalluria from negative crystalluria.

Multisystem inflammatory syndrome in children: Inputs of BNP, NT-proBNP and Galectin-3.

BACKGROUND: Since the COVID-19 pandemic began, a cohort of Multisystem inflammatory syndrome in children (MIS-C) patients has been described. Cardiac involvement is found in 80-85% patients, typically with cardiac dysfunction with or without cardiogenic shock. Here, three cardiac biomarkers, BNP, NT-proBNP and Galectin-3 were compared for the first time in MIS-C in a unique cohort of hospitalized French children. METHODS: Fourteen children with MIS-C hospitalized at Necker-Enfants Malades for cardiac management during the first three COVID-19 waves (March 2020-March 2021) were included. All had positive SARS-CoV-2 serology and proven cardiac involvement assessed by transthoracic echocardiography. NT-proBNP, BNP and Galectin-3 were measured at admission, discharge and first follow-up clinic. RESULTS: All admission Galectin-3 measurements were comprised within the reference interval, both in patients with and without cardiogenic shock, and did not vary between admission, discharge and first follow-up clinic. Both median admission BNP and NT-proBNP were higher in children with cardiogenic shock than without. Median admission NT-proBNP was higher than its predictive positive value in heart failure in both groups of children, while median BNP was below its negative predictive value in children without cardiogenic shock but with cardiac dysfunction. CONCLUSIONS: Galectin-3 does not seem affected by MIS-C. NT-proBNP seems to increase more precociously than BNP possibly making it a more sensitive marker for screening of heart failure in MIS-C.

Comparison of blood gas results obtained on Abbott i-Stat® and on Radiometer ABL 800 Flex® analyzers Impact for the clinical decision

Background: Point of care testing (POCT) tests are needed to assess severity and to help for triage in hospital and in prehospital settings. Before their use, the analytical performances of POCTs have to be compared with central laboratory reference methods. In this study, we describe the comparability of results obtained by either the Abbott i-STAT® System POCT handheld device or the blood gases analyzer of the central laboratory of our hospital. Methods: Sample blood from 37 septic patients admitted to the intensive care unit (ICU) were assayed by Abbott i-STAT® System POCT and Radiometer ABL800 Flex® lab analyzer. Studied parameters were as follows: pH, pO2, pCO2, base excess (BE), HCO3- and lactate. Comparability was evaluated using Bland-Altman method. The clinical value for possible mismatch issued of values differences was also assessed. Results: Quite acceptable correlations in results of POCT and laboratory analyzer were observed with R² most of time above 0.85. Bland-Altman analysis showed a bias of 1.26% for Abbott i-STAT® System POCT vs laboratory. Conclusion: Abbott i-STAT® System POCT handheld device is comparable to Radiometer ABL800 Flex® lab analyzer and concordant with laboratory analysis. Abbott i-STAT® System POCT handled device could be used in the prehospital settings in order to evaluate the severity of sepsis.

Contexte: Les dispositifs médicaux de biologie délocalisée peuvent être utiles pour évaluer la gravité et aider au triage des patients à la fois en milieu hospitalier mais aussi en milieu préhospitalier. Avant leur utilisation, les performances analytiques de ces dispositifs médicaux doivent être comparées aux méthodes de référence des laboratoires hospitaliers. Dans cette étude, nous décrivons la comparabilité des résultats obtenus soit par le dispositif portable Abbott i-STAT® avec ceux fournis par l'analyseur de gaz du sang du laboratoire central de notre hôpital. Méthodes: Des échantillons de sang provenant de 37 patients septiques admis en réanimation ont été analysés par le système Abbott i-STAT® et l'analyseur de laboratoire Radiometer ABL800 Flex®. Les paramètres étudiés étaient les suivants : pH, pO2, pCO2, excès de base (BE), HCO3- et lactate. La comparabilité a été évaluée par la méthode de Bland-Altman. La valeur clinique de l'éventuelle inadéquation issue des différences de valeurs a également été évaluée. Résultats: Des corrélations tout à fait acceptables entre les résultats du système Abbott i-STAT® et de l'analyseur de laboratoire ont été observées, avec un R² le plus souvent supérieur à 0,85. L'analyse Bland-Altman a montré un biais de 1,26 % pour le système Abbott i-STAT® par rapport aux résultats fournis par l'analyseur du laboratoire. Conclusion: Le dispositif de biologie délocalisée Abbott i-STAT® est comparable et concordant avec l'analyseur de laboratoire Radiometer ABL800 Flex®. Le dispositif Abbott i-STAT® System POCT pourrait être utilisé en milieu préhospitalier afin d'évaluer la gravité de patients atteints de sepsis.

[Myocardial injury in coronavirus disease 19 (Covid-19): main pathophysiological mechanisms and clinical utility of cardiac biomarkers]. / Atteintes myocardiques au cours de la maladie à coronavirus 19 (Covid-19) : principaux mécanismes physiopathologiques et utilité clinique des biomarqueurs cardiaques.

Covid-19 is responsible for myocardial injury in many infected patients, which is associated with severe disease and critical illness. The mechanisms by which SARS-CoV-2 may cause myocardial damage involve direct effect of the virus in cardiac cells and indirect effect due to the clinical consequences of Covid-19. Cardiomyocytes are well known to express Angiotensin-Converting Enzyme-2 receptors (ACE-2) to facilitate the virus cell entry, which could explain the occurrence of myocarditis, functional alterations in the myocardium, and more rarely, myocardial infarction. Myocardial injury may also be secondary to systemic inflammation or coagulopathy due to complicated Covid-19. The existence of a cardio-intestinal axis with alteration of tryptophan metabolism in the small bowel leading first to colitis and then to systemic inflammation has also been evoked to explain the myocardial injury. Morphological and metabolic disturbances of the heart during the Covid-19 are associated with elevated concentrations of cardiac blood biomarkers, mainly troponins and natriuretic peptides. The determination of these biomarkers has proven to be very useful for diagnosis, prognosis, and risk stratification. Indeed, recent data demonstrated that about 20% of infected patients admitted to the hospital have elevated troponin or BNP levels, and Covid-19 patients with elevated troponin concentrations beyond the diagnostic threshold (99th percentile) were associated with a higher risk of in-hospital mortality. In conclusion, after more than a year of a unique global pandemic, it is now clearly established that myocardial injury during Covid-19 is frequent and strongly contributes to the severity of the disease. Cardiac alterations secondary to direct infection of cardiac cells by SARS-CoV-2 or to the clinical consequences of Covid-19 are associated with elevated levels of cardiac biomarkers in blood, whose measurement is crucial in clinical decision making.

Mitochondrial dynamics and reactive oxygen species initiate thrombopoiesis from mature megakaryocytes.

Blood platelets are essential for controlling hemostasis. They are released by megakaryocytes (MKs) located in the bone marrow, upon extension of cytoplasmic protrusions into the lumen of bone marrow sinusoids. Their number increases in postpulmonary capillaries, suggesting a role for oxygen gradient in thrombopoiesis (ie, platelet biogenesis). In this study, we show that initiation of thrombopoiesis from human mature MKs was enhanced under hyperoxia or during pro-oxidant treatments, whereas antioxidants dampened it. Quenching mitochondrial reactive oxygen species (mtROS) with MitoTEMPO decreased thrombopoiesis, whereas genetically enhancing mtROS by deacetylation-null sirtuin-3 expression increased it. Blocking cytosolic ROS production by NOX inhibitors had no impact. Classification according to the cell roundness index delineated 3 stages of thrombopoiesis in mature MKs. Early-stage round MKs exhibited the highest index, which correlated with low mtROS levels, a mitochondrial tubular network, and the mitochondrial recruitment of the fission activator Drp1. Intermediate MKs at the onset of thrombopoiesis showed high mtROS levels and small, well-delineated mitochondria. Terminal MKs showed the lowest roundness index and long proplatelet extensions. Inhibiting Drp1-dependent mitochondrial fission of mature MKs by Mdivi-1 favored a tubular mitochondrial network and lowered both mtROS levels and intermediate MKs proportion, whereas enhancing Drp1 activity genetically had opposite effects. Reciprocally, quenching mtROS limited mitochondrial fission in round MKs. These data demonstrate a functional coupling between ROS and mitochondrial fission in MKs, which is crucial for the onset of thrombopoiesis. They provide new molecular cues that control initiation of platelet biogenesis and may help elucidate some unexplained thrombocytopenia.

The Emerging Role of TXNIP in Ischemic and Cardiovascular Diseases; A Novel Marker and Therapeutic Target.

Thioredoxin interacting protein (TXNIP) is a metabolism- oxidative- and inflammation-related marker induced in cardiovascular diseases and is believed to represent a possible link between metabolism and cellular redox status. TXNIP is a potential biomarker in cardiovascular and ischemic diseases but also a novel identified target for preventive and curative medicine. The goal of this review is to focus on the novelties concerning TXNIP. After an overview in TXNIP involvement in oxidative stress, inflammation and metabolism, the remainder of this review presents the clues used to define TXNIP as a new marker at the genetic, blood, or ischemic site level in the context of cardiovascular and ischemic diseases.

Prehospital lactate clearance is associated with reduced mortality in patients with septic shock.

BACKGROUND: Assessment of disease severity in patients with septic shock (SS) is crucial in determining optimal level of care. In both pre- and in-hospital settings, blood lactate measurement is broadly used in combination with the clinical evaluation of patients as the clinical picture alone is not sufficient for assessing disease severity and outcomes. METHODS: From 15th April 2017 to 15th April 2019, patients with SS requiring prehospital mobile Intensive Care Unit intervention (mICU) were prospectively included in this observational study. Prehospital blood lactate clearance was estimated by the difference between prehospital (time of first contact between the patients and the mICU prior to any treatment) and in-hospital (at hospital admission) blood lactate levels divided by prehospital blood lactate. RESULTS: Among the 185 patients included in this study, lactate measurement was missing for six (3%) in the prehospital setting and for four (2%) at hospital admission, thus 175 (95%) were analysed for prehospital blood lactate clearance (mean age 70 ± 14 years). Pulmonary, digestive and urinary infections were probably the cause of the SS in respectively 56%, 22% and 10% of the cases. The 30-day overall mortality was 32%. Mean prehospital blood lactate clearance was significantly different between patients who died and those who survived (respectively 0.41 ± 2.50 mmol.l-1 vs 1.65 ± 2.88 mmol.l-1, p = 0.007). Cox regression analysis showed that 30-day mortality was associated with prehospital blood lactate clearance > 10% (HRa [CI95] = 0.49 [0.26-0.92], p = 0.028) and prehospital blood lactate clearance < 10% (HRa [CI95] = 2.04 [1.08-3.84], p = 0.028). CONCLUSION: A prehospital blood lactate clearance < 10% is associated with 30-day mortality increase in patients with SS handled by the prehospital mICU. Further studies will be needed to evaluate if prehospital blood lactate clearance alone or combined with clinical scores could affected the triage decision-making process for those patients.

Pre-Hospital Lactatemia Predicts 30-Day Mortality in Patients with Septic Shock-Preliminary Results from the LAPHSUS Study.

BACKGROUND: Assessment of disease severity in patients with septic shock (SS) is crucial in determining optimal level of care. In both pre- and in-hospital settings, the clinical picture alone is not sufficient for assessing disease severity and outcomes. Because blood lactate level is included in the clinical criteria of SS it should be considered to improve the assessment of its severity. This study aims to investigate the relationship between pre-hospital blood lactate level and 30-day mortality in patients with SS. METHODS: From 15 April 2017 to 15 April 2019, patients with SS requiring pre-hospital Mobile Intensive Care Unit intervention (MICU) were prospectively included in the LAPHSUS study, an observational, non-randomized controlled study. Pre-hospital blood lactate levels were measured at the time of first contact between the patients and the MICU. RESULTS: Among the 183 patients with septic shock requiring action by the MICU drawn at random from LAPHSUS study patients, six (3%) were lost to follow-up on the 30th day and thus 177 (97%) were analyzed for blood lactate levels (mean age 70 ± 14 years). Pulmonary, urinary and digestive infections were probably the cause of the SS in respectively 58%, 21% and 11% of the cases. The 30-day overall mortality was 32%. Mean pre-hospital lactatemia was significantly different between patients who died and those who survived (respectively 7.1 ± 4.0 mmol/L vs. 5.9 ± 3.5 mmol/L, p < 10-3). Using Cox regression analysis adjusted for potential confounders we showed that a pre-hospital blood lactate level ≥ 4 mmol/L significantly predicted 30-day mortality in patients with SS (adjusted hazard ratio = 2.37, 95%CI (1.01-5.57), p = 0.04). CONCLUSION: In this study, we showed that pre-hospital lactatemia predicts 30-day mortality in patients with septic shock handled by the MICU. Further studies will be needed to evaluate if pre-hospital lactatemia alone or combined with clinical scores could affect the triage decision-making process for those patients.

[SFBC working group "Biochemical markers of COVID-19"]. / Groupe de travail SFBC « Marqueurs biochimiques de COVID-19 ¼.

The SARS-CoV-2 virus is responsible for an epidemic disease called COVID-19, which was initially evidenced in Wuhan, China, and spread very rapidly in China and around the world. In France, the first isolated case seems now to be reported in December 2019, stage 3 of the COVID-19 epidemic was triggered on March 14th, the start of the planned containment exit from May 11th. Healthcare services have faced a large influx of patients who may be beyond their capacity to receive and care, particularly in the Large-East and Ile-de-France regions. Some patients show an evolution of the disease never observed before with other coronaviruses and develop in a few days a very important inflammatory reaction, which can lead to death of patients. A working group of the French Society of Clinical Biology (SFBC) was set up with the objective of providing updated information on the current status of the biological prescriptions (focusing on biochemistry ones) and their evolution during the epidemic, and of analyzing the biological parameters associated with comorbidities and patient evolution in order to link biological results with medical events. The expanded working group covers all sectors of medical biology in France and extends to the French-speaking world: hospital sectors (CHU and CH, Army Training Hospitals) and the private sector opening a field of view on the biological situation in establishments for dependent elderly, social establishments and clinical medical institutions. The purpose of this article is the presentation of this working group and its immediate and future actions.

Targeting endothelial thioredoxin-interacting protein (TXNIP) protects from metabolic disorder-related impairment of vascular function and post-ischemic revascularisation.

INTRODUCTION: Although thioredoxin-interacting protein (TXNIP) is involved in a variety of biological functions, the contribution of endothelial TXNIP has not been well-defined in regards to endothelial and vascular function or in post-ischemic revascularisation. We postulated that inhibition of endothelial TXNIP with siRNA or in a Cre-LoxP system could be involved in protection from high fat, high protein, low carbohydrate (HFHPLC) diet-induced oxidative stress and endothelial dysfunction, leading to vascular damage and impaired revascularisation in vivo. METHODS AND RESULTS: To investigate the role of endothelial TXNIP, the TXNIP gene was deleted in endothelial cells using anti-TXNIP siRNA treatment or the Cre-LoxP system. Murine models were fed a HFHPLC diet, known to induce metabolic disorders. Endothelial TXNIP targeting resulted in protection against metabolic disorder-related endothelial oxidative stress and endothelial dysfunction. This protective effect mitigates media cell loss induced by metabolic disorders and hampered metabolic disorder-related vascular dysfunction assessed by aortic reactivity and distensibility. In aortic ring cultures, metabolic disorders impaired vessel sprouting and this alteration was alleviated by deletion of endothelial TXNIP. When subjected to ischemia, mice fed a HFHPLC diet exhibited defective post-ischemic angiogenesis and impaired blood flow recovery in hind limb ischemia. However, reducing endothelial TXNIP rescued metabolic disorder-related impairment of ischemia-induced revascularisation. CONCLUSION: Collectively, these results show that targeting endothelial TXNIP in metabolic disorders is essential to maintaining endothelial function, vascular function and improving ischemia-induced revascularisation, making TXNIP a potential therapeutic target for therapy of vascular complications related to metabolic disorders.

Impact of 3-week citrulline supplementation on postprandial protein metabolism in malnourished older patients: The Ciproage randomized controlled trial.

BACKGROUND: Citrulline (CIT), is not extracted by the splanchnic area, can stimulate muscle protein synthesis and could potentially find clinical applications in conditions involving low amino acid (AA) intake, such as in malnourished older subjects. OBJECTIVE: Our purpose was to research the effects of CIT supplementation on protein metabolism in particular on non-oxidative leucine disposal (NOLD, primary endpoint), and splanchnic extraction of amino acids in malnourished older patients. DESIGN: This prospective randomized multicenter study determined whole-body and liver protein synthesis, splanchnic protein metabolism and appendicular skeletal muscle mass (ASMM) in 24 malnourished older patients [80-92 years; 18 women and 6 men] in inpatient rehabilitation units. All received an oral dose of 10 g of CIT or an equimolar mixture of six non-essential amino acids (NEAAs), as isonitrogenous placebo, for 3 weeks. RESULTS: NOLD and albumin fractional synthesis rates were not different between the NEAA and CIT groups. Splanchnic extraction of dietary amino acid tended to decrease (p = 0.09) in the CIT group (45.2%) compared with the NEAA group (60.3%). Total differences in AA and NEAA area under the curves between fed-state and postabsorptive-state were significantly higher in the CIT than in the NEAA group. There were no significant differences for body mass index, fat mass (FM), lean mass (LM) or ASMM in the whole population except for a tendential decrease in FM for the citrulline group (p = 0.089). Compared with Day 1, lean mass and ASMM significantly increased (respectively p = 0.016 and p = 0.018) at Day 20 in CIT-treated women (mean respective increase of 1.7 kg and 1.1 kg), and fat mass significantly decreased (p = 0.001) at Day 20 in CIT-group women (mean decrease of 1.3 kg). CONCLUSIONS: Our results demonstrate that CIT supplementation has no effect on whole-body protein synthesis or liver protein synthesis in malnourished older subjects. However, CIT supplementation was associated with a higher systemic AA availability. In the subgroup of women, CIT supplementation increased LM and ASMM, and decreased FM.

Human catalase gene promoter haplotype and cardiometabolic improvement after bariatric surgery.

Although its powerful impact on most co-morbidities has been widely demonstrated, the metabolic outcomes of bariatric surgery (BS) show a great heterogeneity among patients. Haplotypes of one of the major antioxidant enzyme, catalase (CAT), are associated with hypertension, dyslipidemia, and diabetes. The haplotype referred to as CAT1 includes homozygous carriers of CATH1 [-844G,-89A,-20T], whereas CAT2 haplotype includes heterozygous carriers (CATH1/CATH2) and CATH2 homozygous [-844A,-89T,-20C]. The aim of our study was to evaluate the impact of CAT1 and CAT2 haplotypes on traditional cardiovascular and metabolic markers one year after BS in a women population. The 294 women with a body mass index (BMI) >35 kg/m2 were followed-up for one year after BS, monitoring their anthropometric, metabolic and inflammatory parameters. CAT1 patients had significantly improved diastolic blood pressure (DBP) and Creactive protein (CRP) levels compared to CAT2 one year after BS. In untreated women at baseline, the change of CRP one year after BS was higher in CAT1 patients. In the population of women receiving at least one anti-lipidic, anti-hypertensive or anti-diabetic treatment at baseline, DBP and fat mass were lower one year after BS in CAT1 patients and the greater change of fat mass was associated with a higher change of adiponectin. The results highlight the beneficial impact of the CAT1 haplotype on traditional cardiovascular and metabolic parameters after BS. Our findings suggest that the CAT1 haplotype could be implicated in the level of metabolic and cardiovascular improvement after BS.

Lactate POCT in mobile intensive care units for septic patients? A comparison of capillary blood method versus venous blood and plasma-based reference methods.

AIM OF THE STUDY: We evaluated if the StatStrip Xpress Meter, a Lactate point of care testing (POCT) handled device, could be a valuable tool in the mobile intensive care units (MICU) to assess the severity of septic patients. METHODS: We first investigated POCT analytical performance, then, using samples collected from 50 identified septic patients admitted to the intensive care unit (ICU), we compared lactate values obtained with the device to those obtained with four central laboratory analysers: one whole blood and three plasma-based methods. RESULTS: Results were compared by least squares regression, Bland-Altman plot and by comparing concordance within clinically relevant lactate ranges. We observed a reliable analytical performance of the POCT (CVs < 3.8% for repeatability and <5.0% for reproducibility) an excellent correlation between POCT and central laboratory analysers (R2: 0.96-0.98, slopes:0.83-0.90, intercepts: 0.02-0.03) and an excellent concordance of the POCT results to the central laboratory analyser results (98-100%). CONCLUSION: Whatever the methodology used, lactate values obtained are comparable and transferable between POCT and central laboratory analysers meaning that POCT could be a valuable tool in the MICU to evaluate the severity of septic patients and to better manage their hospital triage.

Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.

Although thioredoxin-interacting protein (TXNIP) is involved in a variety of biologic functions, the contribution of endothelial TXNIP has not been well defined. To investigate the endothelial function of TXNIP, we generated a TXNIP knockout mouse on the Cdh5-cre background (TXNIPfl/fl cdh5cre). Control (TXNIPfl/fl) and TXNIPfl/fl cdh5cre mice were fed a high protein-low carbohydrate (HP-LC) diet for 3 mo to induce metabolic stress. We found that TXNIPfl/fl and TXNIPfl/fl cdh5cre mice on an HP-LC diet displayed impaired glucose tolerance and dyslipidemia concretizing the metabolic stress induced. We evaluated the impact of this metabolic stress on mice with reduced endothelial TXNIP expression with regard to arterial structure and function. TXNIPfl/fl cdh5cre mice on an HP-LC diet exhibited less endothelial dysfunction than littermate mice on an HP-LC diet. These mice were protected from decreased aortic medial cell content, impaired aortic distensibility, and increased plasminogen activator inhibitor 1 secretion. This protective effect came with lower oxidative stress and lower inflammation, with a reduced NLRP3 inflammasome expression, leading to a decrease in cleaved IL-1ß. We also show the major role of TXNIP in inflammation with a knockdown model, using a TXNIP-specific, small interfering RNA included in a lipoplex. These findings demonstrate a key role for endothelial TXNIP in arterial impairments induced by metabolic stress, making endothelial TXNIP a potential therapeutic target.-Bedarida, T., Domingues, A., Baron, S., Ferreira, C., Vibert, F., Cottart, C.-H., Paul, J.-L., Escriou, V., Bigey, P., Gaussem, P., Leguillier, T., Nivet-Antoine, V. Reduced endothelial thioredoxin-interacting protein protects arteries from damage induced by metabolic stress in vivo.

Role of myocardial collagen degradation and fibrosis in right ventricle dysfunction in transposition of the great arteries after atrial switch.

BACKGROUND: Heart failure is a serious event in patients with transposition of the great arteries (D-TGA) after atrial redirection surgery. We aimed to determine the association between myocardial fibrosis and systolic and diastolic systemic right ventricle (sRV) dysfunction. METHODS: Diastolic and systolic function of sRV was prospectively assessed using echocardiography and cardiac magnetic resonance imaging (CMR) in 48 patients with atrially switched D-TGA and 26 healthy subjects. Diastolic function of the subaortic ventricle was assessed by echocardiography Doppler and DTI. In CMR, ejection fraction of sRV and wall stress defined as the product of the systolic blood pressure and volume/mass ratio were assessed. Fibrosis extent within sRV myocardium was evaluated using gadolinium-enhanced magnetic resonance and serum collagen turnover biomarkers. RESULTS: Late gadolinium enhancement (LGE) was found in 35% of D-TGA patients, and the collagen degradation biomarker pro-MMP1:TIMP1 ratio was significantly increased in D-TGA patients compared to healthy subjects (1.0 × 10-2vs. 2.5 × 10-2, p = 0.04). Increase in sRV wall stress was significantly associated with LGE (p = 0.01) and pro-MMP1:TIMP1 ratio (r = 0.77, p < 0.01). After adjustment for age, sex, BMI, blood pressure and cardiac treatment, pro-MMP1:TIMP1 ratio was the strongest determinant of sRVEF (R2 = 0.85, p < 0.01). Pro-MMP1:TIMP1 ratio was also significantly correlated with the early diastolic filling parameter E/E' (r = 0.53, p = 0.02), but this was not anymore the case after adjustment. CONCLUSIONS: Diastolic and systolic sRV dysfunction is related to myocardial collagen degradation and fibrosis. Research in medical therapies that reduce systemic sRV afterload and limit collagen degradation is warranted in this setting.

[Determination of procalcitonin (PCT) in micro-method on AQT90 FLEX® analyzer and in vitro stability study]. / Dosage de la procalcitonine (PCT) en microméthode sur analyseur AQT90 FLEX® et étude de la stabilité in vitro.

Radiometer® has developed a point-of-care test for fast PCT measurement on whole blood in micromethod on a AQT90 FLEX® instrument. We have verified the analytical performances of the AQT90 FLEX® PCT assay in heparinized macrotube and EDTA microtube for pediatric use, according to modified French Society of Clinical Biology (SFBC) protocol to the requirements of the standard NF EN ISO 15189: 2012. The samples (n=61, 30 macrotubes, 31 microtubes) were analyzed by the Brahms Kryptor Compact Plus® reference method vs the AQT90 FLEX®. In a second step, we studied the stability of the PCT at room temperature for 24 h. A good correlation between the two methods on macro- or microtubes is observed (respectively r=0.990 and 0.993). The Bland-Altmann representations confirm the excellent correlation with a deviant, above the acceptable limit, which was calculated according to ISO 5725-6, for each type of tube and for the two concentration ranges (lower and greater than 1 ng/mL). The biases observed do not affect the clinical decision. No degradation of PCT after 24 h was demonstrated by the Mann and Whitney test on macro- and microtubes (p=0.50 and 0.34, respectively). The determination of PCT on AQT90 FLEX® has satisfactory analytical characteristics and can be used as point-of-care testing device on whole blood without pre-analytical treatment. In heparinized macrotube and EDTA microtube, the PCT is stable at room temperature up to 24 h.

Distribution of trans-resveratrol and its metabolites after acute or sustained administration in mouse heart, brain, and liver.

SCOPE: Trans-resveratrol is widely studied for its potentially beneficial effects on numerous disorders. It is rapidly metabolized and its metabolites can exhibit biological activity. The present study aimed to investigate whether acute or sustained trans-resveratrol administration impacted on the distribution of trans-resveratrol and its metabolites in brain, heart, and liver. METHODS AND RESULTS: We used ultra-HPLC quadrupole-TOF (UHPLC-Q-TOF) in a full-scan mode to identify and assess large numbers of resveratrol metabolites. For acute intake, mice were overfed with a single dose of trans-resveratrol (150 mg/kg) and organs were collected after 30 and 60 min. For sustained intake, trans-resveratrol was given in the chow (0.04% w/w corresponding to 40 mg/kg/day), and plasma and the organs were collected after 3 months of this resveratrol diet. We found that trans-resveratrol-3-O-glucuronide and resveratrol-3-sulfate were the main metabolites found after acute intake, and free trans-resveratrol (in the brain and heart) and dihydroresveratrol derivatives were found after sustained administration CONCLUSIONS: Our results show notable differences between acute and sustained administration of trans-resveratrol and distribution of trans-resveratrol and its metabolites in mouse heart, brain, and liver. The results suggest a strategy for development of galenic forms of resveratrol.