Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Using passive acoustic monitoring to assess humpback whale occurrence and breeding activity around La Réunion Island

Humpback whales use the coastal waters of La Réunion Island seasonally from June to October. Their distribution is relatively well-known on the west coast, which provides suitable breeding habitat, however little is known about their use and movement along the south and east coast of the island. Three autonomous acoustic recorders were deployed during the breeding season of 2016 off the west, south and east coasts to investigate spatial and temporal variations in humpback whale occurrence around the island. The dataset consisted of 10 minute acoustic recordings every hour, continuously from mid-June to early September from these three locations. Song and social call events were discriminated and their total durations were calculated and expressed as a percentage of the total recording duration per day. Off the west and south coast, social calls were distributed fairly homogenously over the season, while songs occurred over a shorter time period, with two significant peaks observed in mid-July and early-August. Off the east coast very few vocalizations were detected. These results demonstrated that humpback whales preferentially use the west coast of the island for breeding. In this area, daily variations in singing activity were observed. Singers appeared to be more active at night and during the morning, when less boat traffic was detected.

Scale matters: sea ice and breeding success of Adélie penguins

International audienceSouthern Ocean ecosystems are extremely vulnerable to sea-ice changes occurring at different spatial and temporal scales. Variability in the sea-ice conditions strongly influence the survival and reproduction of animals that are synchronized with the seasonality of sea ice. Although the linkages between Adélie penguins (Pygoscelis adeliae) and sea-ice conditions are well established, the spatial and temporal scales at which sea ice affects individuals and populations are poorly known. Using 23 years of penguin breeding success and remote-sensing data of sea ice, we investigate the spatial and temporal scales at which sea-ice changes best explain variations in the reproductive success of Adélie penguins at Pointe Géologie, East Antarctica. The best spatial scale encompassed all foraging areas exploited and all the sea-ice conditions encountered by penguins over a breeding season. There was a consistent influence of sea-ice concentration during the guard stage on the overall breeding success. We demonstrate the importance of considering sea ice at a fine temporal scale rather than using an average value over the breeding season to best explain reproductive success in Adélie penguins

Chronic wound healing: A specific antibiofilm protein-asymmetric release system

International audienc

Chronic wound healing: A specific antibiofilm protein-asymmetric release system

International audienc

Adipose-derived cardiomyogenic cells: in vitro expansion and functional improvement in a mouse model of myocardial infarction

1755-3245 (Electronic) Journal Article Research Support, Non-U.S. Gov'tAIMS: Cells derived from the stroma vascular fraction (SVF) of mouse adipose tissue can spontaneously give rise to rare, functional, cardiac-like cells in vitro. This study aimed to improve the production of adipose-derived cardiomyogenic cells (AD-CMG), to characterize them and to assess their cardiac fate and functional outcomes after their administration in a mouse model of acute myocardial infarction. METHODS AND RESULTS: The culture process optimized to improve in vitro cardiac specification consisted of a primary culture of murine SVF cells in semi-solid methylcellulose medium, a selection of AD-CMG cell clusters, and a secondary culture and expansion in BHK21 medium. AD-CMG cells were CD29(+), CD31(-), CD34(-), CD44(+), CD45(-), CD81(+), CD90(-), CD117(-), and Flk-1(-) and expressed several cardiac contractile proteins. After 1, 2, and 4 weeks of their injection in mice having acute myocardial infarction, a strong presence of green fluorescent protein-positive cells was identified by immunohistochemistry as well as quantitative polymerase chain reaction. Echocardiography showed a significant reduction of remodelling and stability of left ventricle ejection fraction in the AD-CMG cell-treated group vs. controls. Vascular density analysis revealed that AD-CMG administration was also associated with stimulation of angiogenesis in peri-infarct areas. CONCLUSION: Cardiomyogenic cells can be selected and expanded in large amounts from mouse adipose tissue. They can survive and differentiate in an acute myocardial infarction model, avoiding remodelling and impairment of cardiac function, and can promote neo-vascularization in the ischaemic heart

Importance of mitochondrial dynamin-related protein 1 in hypothalamic glucose sensitivity in rats.

International audienceAIMS: Hypothalamic mitochondrial reactive oxygen species (mROS)-mediated signaling has been recently shown to be involved in the regulation of energy homeostasis. However, the upstream signals that control this mechanism have not yet been determined. Here, we hypothesize that glucose-induced mitochondrial fission plays a significant role in mROS-dependent hypothalamic glucose sensing. RESULTS: Glucose-triggered translocation of the fission protein dynamin-related protein 1 (DRP1) to mitochondria was first investigated in vivo in hypothalamus. Thus, we show that intracarotid glucose injection induces the recruitment of DRP1 to VMH mitochondria in vivo. Then, expression was transiently knocked down by intra-ventromedial hypothalamus (VMH) DRP1 siRNA (siDRP1) injection. 72 h post siRNA injection, brain intracarotid glucose induced insulin secretion, and VMH glucose infusion-induced refeeding decrease were measured, as well as mROS production. The SiDRP1 rats decreased mROS and impaired intracarotid glucose injection-induced insulin secretion. In addition, the VMH glucose infusion-induced refeeding decrease was lost in siDRP1 rats. Finally, mitochondrial function was evaluated by oxygen consumption measurements after DRP1 knock down. Although hypothalamic mitochondrial respiration was not modified in the resting state, substrate-driven respiration was impaired in siDRP1 rats and associated with an alteration of the coupling mechanism. INNOVATION AND CONCLUSION: Collectively, our results suggest that glucose-induced DRP1-dependent mitochondrial fission is an upstream regulator for mROS signaling, and consequently, a key mechanism in hypothalamic glucose sensing. Thus, for the first time, we demonstrate the involvement of DRP1 in physiological regulation of brain glucose-induced insulin secretion and food intake inhibition. Such involvement implies DRP1-dependent mROS production

6-Polyaminosteroid Squalamine Analogues Display Antibacterial Activity against Resistant Pathogens

International audienceA series of 6-polyaminosteroid analogues of squalamine were synthesized with moderate to good yields and evaluated for their in vitro antimicrobial properties against both susceptible and resistant Gram-positive (vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus) and Gram-negative (carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa) bacterial strains. Minimum inhibitory concentrations against Gram-positive bacteria ranged from 4 to 16 µg/mL for the most effective compounds, 4k and 4n, and showed an additive or synergistic effect with vancomycin or oxacillin. On the other hand, the derivative 4f, which carries a spermine moiety like that of the natural trodusquemine molecule, was found to be the most active derivative against all the resistant Gram-negative bacteria tested, with an MIC value of 16 µg/mL. Our results suggest that 6-polyaminosteroid analogues of squalamine are interesting candidates for Gram-positive bacterial infection treatments, as well as potent adjuvants to fight Gram-negative bacterial resistance

The Release of Adipose Stromal Cells from Subcutaneous Adipose Tissue Regulates Ectopic Intramuscular Adipocyte Deposition

Summary: Ectopic lipid deposition (ELD) is defined by excess fat storage in locations not classically associated with adipose tissue (AT) storage. ELD is positively correlated with insulin resistance and increased risk of metabolic disorders. ELD appears as lipid droplets or adipocytes, whose cell origin is unknown. We previously showed that subcutaneous AT (ScAT) releases adipocyte progenitors into the circulation. Here, we demonstrate that triggering or preventing the release of adipocyte precursors from ScAT directly promoted or limited ectopic adipocyte formation in skeletal muscle in mice. Importantly, obesity-associated metabolic disorders could be mimicked by causing adipocyte precursor release without a high-fat diet. Finally, during nutrient overload, adipocyte progenitors exited ScAT, where their retention signals (CXCR4/CXCL12 axis) were greatly decreased, and further infiltrated skeletal muscles. These data provide insights into the formation of ELD associated with calorie overload and highlight adipocyte progenitor trafficking as a potential target in the treatment of metabolic diseases. : Girousse et al. show that, in mice fed a high-fat diet, adipose stromal cells (ASCs) can egress subcutaneous adipose tissue and infiltrate skeletal muscle to form ectopic adipocytes, causing metabolic disturbance. ASC trafficking is regulated by the CXCR4/CXCL12 axis, and pioglitazone intermittent treatment can prevent muscle ectopic lipid deposition. Keywords: ectopic adipocytes, adipose stem or stromal cells, intramuscular adipocyte, thiazolidinedione, type 2 diabetes, CXCR4/CXCL12, AMD3100, lymphatic system, chemotaxi