Transient self-potential anomalies associated with recent lava flows at Piton de la Fournaise volcano (Réunion Island, Indian Ocean)

International audienceSelf-potential signals are sensitive to various phenomena including ground water flow (streaming potential), thermal gradients (thermoelectric potential), and potentially rapid fluid disruption associated with vaporization of water. We describe transient self-potential anomalies observed over recent (< 9 years) lava flows at Piton de la Fournaise volcano (Reunion Island, Indian Ocean). Repeated self-potential measurements are used to determine the decay of the self-potential signals with time since the emplacement of a set of lava flow. We performed a 9 km-long self-potential profile in February 2004 in the Grand Brûlé area. This profile was repeated in July–August 2006. The second repetition of this profile crossed eight lava flows emplaced between 1998 and 2005 during seven eruptions of Piton de la Fournaise volcano. The self-potential data show clear positive anomalies (up to 330 mV) and spatially correlated with the presence of recent lava flows. The amplitude of the self-potential anomalies decreases exponentially with the age of the lava flows with a relaxation time of not, vert, similar 44 months. We explain these anomalies by the shallow convection of meteoric water and the associated streaming potential distribution but we cannot exclude possible contributions from the thermoelectric effect and the rapid fluid disruption mechanism. This field case evidences for the first time transient self-potential signals associated with recent volcanic deposits. It can be also a shallow analogue to understand the variation of self-potential signals in active geothermal areas and transient self-potential signals associated with dike intrusion at larger depths. The empirical equation we proposed can also be used to diagnose the cooling of recent lava flow on shield volcanoes

Quelle alimentation proposer aux patients présentant une stéatohépatite non-alcoolique ?

La maladie stéatosique du foie liée à une dysfonction métabolique (MAFLD) touche un quart de la population mondiale, dont certains d’entre eux évolueront vers une forme plus sévère appelée stéatohépatite non-alcoolique (NASH). Le principal facteur menant à cette pathologie est une alimentation déséquilibrée. Aucun traitement médicamenteux n’est reconnu à ce jour. Seule la prise en charge hygiénodiététique permet une amélioration des lésions histologiques de la NASH grâce à une perte de poids. Néanmoins, l’efficacité des régimes standards, la compliance des patients et la capacité à maintenir la perte de poids à long terme sont des difficultés fréquemment rencontrées. Dans cet article, nous analysons les données scientifiques récentes de différents types d’alimentation (régime méditerranéen, jeûne intermittent, régime cétogène) permettant d’apporter des bénéfices hépatiques et parfois extrahépatiques. Les inconvénients ou limites possibles sont également discutés. Le bénéfice éventuel d’autres stratégies nutritionnelles (café, acides gras oméga-3, polyphénols…) est finalement présenté. Le changement de mode alimentaire peut, dès lors, être adapté aux attentes du patient et occasionner des bénéfices indépendamment de la perte de poids.Metabolic dysfunction-associated fatty liver disease (MAFLD) affects a quarter of the world’s population,some of whom will progress to a more severe form called non-alcoholic steatohepatitis (NASH). Themain factor leading to this condition is an unbalanced diet. No drug treatment is approved to date andonly dietary management can improve the histological lesions of NASH through weight loss. However,the efficacy of standard diets, patient compliance and the ability to maintain weight loss over the longterm are common difficulties. In this review, we analyze recent scientific data on different types of diet(Mediterranean diet, intermittent fasting, ketogenic diet), which can bring benefits on general and liverhealth. Drawbacks or limitations are also listed. The possible benefit of other nutritional strategies (coffeeconsumption, omega-3, polyphenols...) is discussed. The value of dietary change could be tailored to thepatient’s needs without necessarily imposing an intense weight loss

Liver elasticity evolution in metabolic dysfunction-associated steatotic liver disease patients: a real-life prospective study

Background Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the first cause of chronic liver disease worldwide with a variable course over time. There is little prospective data on the long-term follow-up of these patients. Aim The aim of our study is to evaluate the evolution of liver disease, in real life, using hepatic elastometry by identifying patients who will improve or progress over time. Methods This is a prospective, single-centre study including patients with MASLD. Transient elastography was performed at baseline and checked after one (Y1) and three years (Y3). Patients were stratified into three groups based on the evolution of liver elasticity. Regression or progression of liver disease were defined as a decrease or increase in liver elasticity of > 1.5 kPa compared with baseline value. Stable patients are those with elasticity changes ≤ 1.5 kPa. Results 229 patients were included (126 women and 103 men) with the following characteristics: mean age 52 years, mean body mass index 33.9 kg/m², significant proportion (98%) with an enlarged waist circumference (F ≥ 80 cm; M ≥ 94 cm) and a mean of 114 centimetres, 20 patients (9%) had an history of cardiovascular events, 86 patients (38%) were treated for type 2 diabetes. The baseline mean liver elasticity was 10.5 kPa (± 8.8) and the mean controlled attenuation parameter (CAP) was 331.1 dB/m (± 43.5). 100 patients (44%) were classified as F0-F1, 64 (28%) as F2, 43 (19%) as F3 and 22 (10%) as F4. Most received lifestyle advice by the hepatologist (n=157, 69%), others underwent bariatric surgery (n=30, 13%), were either included in an interventional clinical study in the context of MASLD or metabolic syndrome (n=21, 9%) or referred to the dietitian (n=18, 8%). 146 patients (64%) and 110 patients (48%) underwent follow-up elastography at one and three years respectively. Mean liver elasticity (Y0: 10.5, Y1: 7.8, Y3: 7.9 kPa; p=0.0008) and CAP (Y0: 331.1, Y1: 307.1, Y3: 317.4 dB/m; p=0.0007) decreased over time. At Y1, a minority of patients were progressors (n=26, 18%), 71 (49%) remained stable, and 49 (34%) exhibited improvement in liver elasticity. After three years (Y3), 21 (19%) experienced progression, 43 (39%) remained stable, and 46 (42%) demonstrated improvement. Interestingly, compared with progressors (P) or stable patients (S), improvers (I) at Y1 exhibit a more severe condition at baseline (Y0), characterized by higher BMI (I: 34.6, S: 31.7, P: 32.5 kg/m²; p=0.05), waist circumference (I: 116, S: 108, P: 110 cm; p=0.0048), fasting glucose (I: 125, S: 105, P: 110 mg/dL; p=0.0015), low HDL (I: 43, S: 52, P: 51 mg/dL; p=0.0157), elasticity (I: 12.2, S: 6.6, P: 7.5 kPa; p<0.0001) and CAP values (I: 343, S: 322, P: 328 dB/m; p=0.05). The same is also true for Y3 vs. baseline (Y0) with additionally an elevated mean AST at Y0 (I: 47, S: 34, P: 39 UI/L; p=0.0012). The improvement in this group is associated at Y1 with a significant BMI reduction (-3.7 kg/m²; -9%) compared with stable patients (-1.1 kg/m², -2.6%) and progressors (-0.1 kg/m², -0.4%) (p=0.0003). At Y3, improvers had also a significant BMI decrease (-2.1 kg/m²; -6%) compared with stable patients (-0.6 kg/m², -1.7%) and progressors (+0,6 kg/m², +1.7%) (p=0.0005). All the patients who underwent bariatric surgery demonstrated disease regression at either one or three-year follow-up, however more than the half (Y1 vs. Y0: 60%, Y3 vs. Y1: 50%) of lost to follow-up patients was seen in this category. Among the events occurring during follow-up, 11 patients developed diabetes, 2 had hepatocellular carcinoma and 2 experienced a cardiovascular event. Conclusion: These are the first prospective data on the evolution of liver elasticity in MASLD patients. Standard hepatological management can have an impact on liver disease, interestingly, particularly in patients with severe initial MASLD. We confirm that a 6 to 9% of loss in BMI is associated with a regression in hepatic elasticity, consistent with regression of fibrosis. Patients who progress represent a fifth of population and are easily identified by the absence of weight loss over time. So, the focus should be on weight reduction

Opposite regulation of metabotropic glutamate receptor 3 and metabotropic glutamate receptor 5 by inflammatory stimuli in cultured microglia and astrocytes.

Metabotropic glutamate receptors (mGluRs) were previously shown to modulate several essential functions in glial cells, including cell proliferation, glutamate uptake, neurotrophic support, and inflammatory responses. As these receptors are regularly proposed as promising targets for the treatment of a wide range of neurological disorders, we herein examined the reciprocal modulation of glial mGluRs by inflammation. Such regulation of mGluRs was also studied in cultures from an experimental model of amyotrophic lateral sclerosis (ALS). Indeed, ALS is characterized by increased neuroinflammation, and glial cell cultures derived from the animal model (rat expressing hSOD1(G93A)) show enhanced glial reactivity. Within 72 h, the pro-inflammatory cytokines tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β) induced an increase in mGluR3 and a decrease in mGluR5 gene expression. A similar regulation of these receptors was observed in microglia 48 h after an initial 4-h exposure to lipopolysaccharide. In hSOD1(G93A)-derived glial cultures, the gene up-regulation of mGluR3 (but not the gene down-regulation of mGluR5) was found to be enhanced in both astrocytes and microglia. Together, these results indicate that an inflammatory environment triggers an opposite regulation in the gene expression of the two predominant mGluR subtypes found in glial cells, and that these regulations were particularly robust in hSOD1(G93A) glial cultures. As neuroinflammation commonly occurs in several nervous diseases, its influence on mGluR expression should be taken into account when considering these receptors as future drug targets

Nutrition et maladie stéatosique du foie : pas d’évidence d’un impact de la consommation d’aliments ultra-transformés sur la sévérité de l’atteinte hépatique

Introduction : La consommation d’aliments ultra-transformés (UPF) est en augmentation et a été associée au risque de maladie hépatique stéatosique d’origine métabolique (MASLD), d’obésité et de diabète de type 2. La relation entre la consommation de ces UPF et l’histologie hépatique dans la MASLD et la maladie hépatique liée à l’alcool (ALD) n’a pas encore été étudiée. Notre objectif est d’évaluer la relation entre apports nutritionnels, consommation d’UPF et marqueurs de sévérité histologique de la maladie hépatique chez des patients avec MASLD ou ALD. Méthode: Les patients avec confirmation histologique d’une MASLD ou d’une ALD ont été recrutés prospectivement. Les apports nutritionnels sont évalués par un rappel de 24h. La consommation d’UPF est mesurée via la classification NOVA. Les boissons alcoolisées fermentées sont classées comme aliments transformés. L’évaluation histologique de la maladie hépatique est réalisée via le score de Beaujon (SAF). Résultats: Soixante-deux patients (46 patients MASLD et 16 patients ALD) ont été inclus. L’âge et indice de masse corporel moyens (IMC) sont de 54 et 52 ans (ns), et 35 et 22kg/m² (p<0.05) pour les patients MASLD et ALD respectivement. Trois patients sont histologiquement stadifiés F0 (4.9%), douze F1 (19.7%), vingt-huit F2 (45.9%), dix-sept F3 (27.9%), et un F4 (1.6%). Pour les apports caloriques, les patients MASLD consomment plus de lipides (73 vs 53g/j; p = 0.05), graisses saturées (29 vs 22g/j; p = 0.02) et fibres (17 vs 8g/j; p = 0.0003) que les patients ALD mais moins de calories au total (1806 vs 2716 kcal/j; p = 0.0003). Il n’y a pas de différence d’apports protéiques ou glucidiques entre MASLD et ALD. Les patients ALD consomment plus d’aliments transformés que les patients MASLD (2628 vs. 196 g/j; p = 0.0001). Aucun lien entre la quantité d’UPF consommée et les degrés de stéatose modérée ou sévère, d’activité faible ou haute, d’absence ou de présence de fibrose hépatique n’est mise en évidence. Conclusion: Les patients ALD consomment plus de calories et d’aliments transformés que les patients MASLD malgré un IMC plus faible. La consommation d’UPF évaluée par un rappel de 24h n’a pas d’impact sur l’histologie hépatique chez les patients MASLD et ALD

Frailty in MASLD patients is associated with the presence of diabetes and the degree of liver fibrosis

Introduction: Loss of muscle strength and mass has been identified as a predictive factor for mortality. It is now evident that the loss of muscle mass and function, or sarcopenia, plays also a significant role in the development and severity of advanced liver diseases. However, the links between muscle strength and the severity of the hepatic phenotype in earlier stages of steatotic diseases are still underexplored. Objective: Our aim is to assess the relationships between muscle strength, frailty, and the severity of liver disease in MASLD patients. Methods: In this prospective study, the frailty of MASLD patients was assessed using the liver frailty index (LFI), including a handgrip strength test for the dominant hand, a balance test, and the time required to perform five sit-to-stand. Forearm and quadriceps muscle strength were measured using handgrip and an isokinetic dynamometer (Cybex®). Hepatic disease severity was evaluated by transient elastography, based on the controlled attenuation parameter (CAP) and elasticity. The presence of diabetes was defined by hypoglycemic medication use. Insulin resistance was evaluated in non-diabetic patients using the HOMA-IR method. Results: 152 patients diagnosed with MASLD were included in this study. The demographic composition of the cohort demonstrated a balanced distribution between genders, with 49% females and 51% males. The mean age was 56 years (range: 19 to 78 years), and the mean body mass index (BMI) was 33 (range 22 to 60 kg/m²). There was a high prevalence of diabetes in the cohort, affecting 45% of participants. Metabolic parameters revealed a mean controlled attenuation parameter (CAP) of 328 dB/m, indicating severe hepatic steatosis. The mean liver elasticity was 8 kPa (range: 2 to 49 kPa). Among the patients assessed by transient elastography, 54 patients were classified as F0-F1 (36.5%), 48 patients as F2 (32.4%), 31 patients as F3 (20.9%), and 15 patients as F4 (10.2%). The mean handgrip strength was 39.1 kg for males and 20.3 kg for females (p = 0.0001). The mean quadriceps strength was 106.9 N-m in males and 72.9 N-m in females (p = 0.0001). Using the LFI, 51 patients (40%) were identified as robust, 70 (56%) as pre-frail, and 5 (4%) as frail. Quadriceps muscle strength was significantly lower in frail patients compared to the robust patients (mean strength: 46.7 vs. 111.8 N-m; p = 0.0036). Frailty was not associated with the degree of steatosis assessed by CAP or insulin resistance measured by HOMA-IR. However, frailty was associated with age (r = 0.4559, p = 0.0001). Besides age, the presence of diabetes was associated with increased frailty (mean LFI 3.3 vs. 2.96 in non-diabetic patients, p = 0.0122) and also higher liver elasticity (mean LFI: 2.97 in F0-F2 vs. 3.5 in F3-F4 patients; p = 0.0008). Conclusion: Frailty and decreased muscle strength are associated with the essential components of MASLD, namely the presence of type 2 diabetes and the degree of liver fibrosis. Other factors such as age and gender should also be considered. This underscores a potential liver-muscle axis in the pathogenesis of the disease

Transient self-potential anomalies associated with recent lava flows at Piton de la Fournaise volcano (Réunion Island, Indian Ocean)

International audienceSelf-potential signals are sensitive to various phenomena including ground water flow (streaming potential), thermal gradients (thermoelectric potential), and potentially rapid fluid disruption associated with vaporization of water. We describe transient self-potential anomalies observed over recent (< 9 years) lava flows at Piton de la Fournaise volcano (Reunion Island, Indian Ocean). Repeated self-potential measurements are used to determine the decay of the self-potential signals with time since the emplacement of a set of lava flow. We performed a 9 km-long self-potential profile in February 2004 in the Grand Brûlé area. This profile was repeated in July–August 2006. The second repetition of this profile crossed eight lava flows emplaced between 1998 and 2005 during seven eruptions of Piton de la Fournaise volcano. The self-potential data show clear positive anomalies (up to 330 mV) and spatially correlated with the presence of recent lava flows. The amplitude of the self-potential anomalies decreases exponentially with the age of the lava flows with a relaxation time of not, vert, similar 44 months. We explain these anomalies by the shallow convection of meteoric water and the associated streaming potential distribution but we cannot exclude possible contributions from the thermoelectric effect and the rapid fluid disruption mechanism. This field case evidences for the first time transient self-potential signals associated with recent volcanic deposits. It can be also a shallow analogue to understand the variation of self-potential signals in active geothermal areas and transient self-potential signals associated with dike intrusion at larger depths. The empirical equation we proposed can also be used to diagnose the cooling of recent lava flow on shield volcanoes

Intramyocellular lipids are associated with insulin resistance in metabolic dysfunction-associated steatotic liver disease

Background and Aims: Insulin resistance is considered an indicator of the severity of MASLD. In this context, the role of skeletal muscle fat and its intra- or extra-myocellular localisation on insulin sensitivity remains debated. The aim of this study is to assess muscle lipid content and cellular localisation using proton-magnetic resonance spectroscopy (1H-MRS) and its relationship with insulin resistance in a cohort of MASLD subjects. Method: MASLD patients were prospectively recruited based on the co-existence of liver steatosis measured by a controlled attenuation-parameter (CAP) above 251 dB/m and at least one cardiometabolic risk factor. Type 2 diabetes was defined by the intake of hypoglycemic drugs. Insulin resistance was estimated in non-diabetic patients using the homeostatic model assessment of insulin resistance (HOMA-IR). Intra (IMCL) and extramyocellular lipids (EMCL) were measured in vivo using 1H-MRS. Single voxel 1H-MRS was performed on a 3-Tesla Signa Premier scanner (GE healthcare) on tibialis anterior (TA) and soleus using a PRESS-sequence (voxel size 10 X 10 X 15 mm3, TE=27ms, TR=1500ms, 8 averages). JMRUI software, including the AMARES algorithm was used to quantify IMCL and EMCL on non-water suppressed spectra. Results: 54 MASLD patients were included. 32 patients were male (59%), with a mean age of 54 years (range: 19-75). 27 patients were diabetic (50%). Mean BMI was 35 (range: 24-60). Mean waist circumference was 118 cm (range: 89-160). Mean CAP and liver elasticity were 342 dB/m (range: 242-400) and 14.8 kPa (range: 3.6-35). In the entire cohort, mean TA lipid content was 0.6% for IMCL (range: 0.1-1.5) and 1.8% (0.3-6.8) for EMCL (p 0.05) or for IMCL for TA between diabetic and non-diabetic patients (0.55% versus 0.7%; p > 0.05). Conclusion: The majority of skeletal muscle lipids are extramyocellular. However, IMCL but not EMCL content assessed by 1H-MRS positively correlates with insulin resistance assessed by the HOMA-IR index in non-diabetic MASLD patients. This observation is reinforced by the IMCL content in diabetic patients being significantly higher compared to non-diabetic patients. This observation highlights a link between IMCL, systemic insulin resistance and type 2 diabetes in MASLD

Dissertatio historica de initiis monarchiae Babyloniorum, quam, cum cons. ampliss. Colleg. Philos. in Reg. Acad. Upsal. sub praesidio ... Jacobi Arrhenii ... publico examini modeste subjicit Petrus Hagberg Gestr. In audit. Gustav. maj. ad d. 25. Maji. Anni MDCCV.

International audienceBackground : The incidence of childhood type 1 diabetes (T1D) incidence is rising in many countries, supposedlybecause of changing environmental factors, which are yet largely unknown. The purpose of the study was tounravel environmental markers associated with T1D. Methods : Cases were children with T1D from the French Isis-Diab cohort. Controls were schoolmates or friends ofthe patients. Parents were asked to fill a 845-item questionnaire investigating the child’s environment before diagnosis.The analysis took into account the matching between cases and controls. A second analysis used propensity scoremethods. Results : We found a negative association of several lifestyle variables, gastroenteritis episodes, dental hygiene, hazelnutcocoa spread consumption, wasp and bee stings with T1D, consumption of vegetables from a farm and death of a petby old age. Conclusions : The found statistical association of new environmental markers with T1D calls for replication in othercohorts and investigation of new environmental areas