Use of Extracorporeal Membrane Oxygenation for Patients with Coronavirus Disease 2019 Infection.

The coronavirus disease 2019 (COVID-19) pandemic was a cataclysmic event that infected over 772 million and killed over 6.9 million people worldwide. The pandemic pushed hospitals and society to their limits and resulted in incredibly severe respiratory disease in millions of people. This severe respiratory disease often necessitated maximum medical therapy, including the use of extracorporeal membrane oxygenation. While our understanding of COVID-19 and its treatment continue to evolve, we review the current evidence to guide the care of patients with severe COVID-19 infection.

Veno-venous or veno-arterial extracorporeal membrane oxygenation support for massive pulmonary embolism: a case report.

Background: With regard to the treatment of massive pulmonary embolism (MPE) with circulatory and respiratory collapse and thrombolytic contraindications, current guidelines and researches usually give the priority to veno-arterial extracorporeal membrane oxygenation (V-A ECMO). However, the objective of this clinical case report is to highlight the effective use of veno-venous extracorporeal membrane oxygenation (V-V ECMO) in a 35-year-old pregnant woman with MPE complicated by hemorrhage, persistent hypoxia and multiple cardiac arrests. Case Description: A 35-year-old pregnant woman with gestational mellitus suddenly presented with complaints of nausea, vomiting and dyspnea after going to the toilet, combined with increasing heart rate (HR) of 150 bpm, decreasing pulse oxygen saturation (SpO2) of 94%, larger right heart and the growing D-dimer at 11.2 µg/mL, who was considered as the pulmonary embolism. Unpredictable cardiac arrest occurred repeatedly before and after the cesarean section. Although cardiopulmonary resuscitation (CPR) was started timely and successfully, the maintenance of blood pressure still depended on high-dose pressor drugs, even terribly, the oxygenation was unstable under the assistance of mechanical ventilation with pure oxygen. Thus, V-V ECMO supporting was commenced following by gradual recovering in haemodynamics and respiratory function. And the diagnosis of MPE was ascertained again through computed tomographic pulmonary angiography (CTPA) and pulmonary angiography. Directing at the pathogeny, thrombolysis infusion catheters and anticoagulant therapy were initiated after bilateral uterine artery embolism for postpartum haemorrhage, later the patient discharged from hospital after recovery and had a good prognosis. Conclusions: V-V ECMO could be effective for some patients with MPE who suffer from successful CPR after cardiac arrest while still combined with severe hypotension and refractory hypoxemia.

High-selective separation recovery of Ni, Co, and Mn from the spent LIBs via acid dissolution and multistage oxidation precipitation.

For recovering Ni, Co, and Mn from lithium-ion batteries, traditional chemical precipitation methods demonstrate low selectivity and significantly contribute to environmental pollution. This study proposes a separation recovery technique for transition metals, specifically Ni, Co, and Mn, from spent LIBs, involving "acid dissolution" and "multistage oxidation precipitation". More than 98% of transition metals can be extracted from spent LIBs using a low acid concentration (0.5 M) without reducing agents. The feasibility of separating different metals via multistage oxidation precipitation, based on their different electrode potentials for oxidizing Me2+ (Me = Mn/Co/Ni), was confirmed. The combination of oxidizing agent S2O82- and the precipitant OH- was universally applied to the fractional precipitation of Mn, Co, and Ni respectively. About 99% of Mn, 97.06% Co, and 96.62% Ni could be precipitated sequentially by changing the concentrations of S2O82- and the pH value of solution. XRD, XPS, XRF, ICP-MS and other methods were employed to elucidate the mechanism behind the multistage oxidation precipitation of target metal compounds, exploiting the differential electrode potentials for oxidizing Me2+ ions. This technique surpasses traditional solvent extraction in cost-effectiveness and selectivity, showing promise for large-scale industrial applications in recovering Mn, Co, and Ni.

Translational insights into the hormetic potential of carbon dioxide: from physiological mechanisms to innovative adjunct therapeutic potential for cancer.

Background: Carbon dioxide (CO2), traditionally viewed as a mere byproduct of cellular respiration, plays a multifaceted role in human physiology beyond simple elimination through respiration. CO2 may regulate the tumor microenvironment by significantly affecting the release of oxygen (O2) to tissues through the Bohr effect and by modulating blood pH and vasodilation. Previous studies suggest hypercapnia (elevated CO2 levels) might trigger optimized cellular mechanisms with potential therapeutic benefits. The role of CO2 in cellular stress conditions within tumor environments and its impact on O2 utilization offers a new investigative area in oncology. Objectives: This study aims to explore CO2's role in the tumor environment, particularly how its physiological properties and adaptive responses can influence therapeutic strategies. Methods: By applying a structured translational approach using the Work Breakdown Structure method, the study divided the analysis into six interconnected work packages to comprehensively analyze the interactions between carbon dioxide and the tumor microenvironment. Methods included systematic literature reviews, data analyses, data integration for identifying critical success factors and exploring extracellular environment modulation. The research used SMART criteria for assessing innovation and the applicability of results. Results: The research revealed that the human body's adaptability to hypercapnic conditions could potentially inform innovative strategies for manipulating the tumor microenvironment. This could enhance O2 utilization efficiency and manage adaptive responses to cellular stress. The study proposed that carbon dioxide's hormetic potential could induce beneficial responses in the tumor microenvironment, prompting clinical protocols for experimental validation. The research underscored the importance of pH regulation, emphasizing CO2 and carbonic acid's role in modulating metabolic and signaling pathways related to cancer. Conclusion: The study underscores CO2 as vital to our physiology and suggests potential therapeutic uses within the tumor microenvironment. pH modulation and cellular oxygenation optimization via CO2 manipulation could offer innovative strategies to enhance existing cancer therapies. These findings encourage further exploration of CO2's therapeutic potential. Future research should focus on experimental validation and exploration of clinical applications, emphasizing the need for interdisciplinary and collaborative approaches to tackle current challenges in cancer treatment.

Relationship between indexed surgery and postcardiotomy extracorporeal life support outcomes.

OBJECTIVES: Veno-arterial extracorporeal life support (V-A ECLS) is increasingly being utilized for postcardiotomy shock (PCS), though data describing the relationship between type of indexed operation and outcomes are limited. This study compared V-A ECLS outcomes across four major cardiovascular surgical procedures. METHODS: This was a single-center retrospective study of patients who required V-A ECLS for PCS between 2015 and 2022. Patients were stratified by the type of indexed operation, which included aortic surgery (AoS), coronary artery bypass grafting (CABG), valve surgery (Valve), and combined CABG and valve surgery (CABG + Valve). Factors associated with postoperative outcomes were assessed using logistic regression. RESULTS: Among 149 PCS patients who received V-A ECLS, there were 35 AoS patients (23.5%), 29 (19.5%) CABG patients, 59 (39.6%) Valve patients, and 26 (17.4%) CABG + Valve patients. Cardiopulmonary bypass times were longest in the AoS group (p < 0.01). Regarding causes of PCS, AoS patients had a greater incidence of ventricular failure, while the CABG group had a higher incidence of ventricular arrhythmia (p = 0.04). Left ventricular venting was most frequently utilized in the Valve group (p = 0.07). In-hospital mortality was worst among CABG + Valve patients (p < 0.01), and the incidence of acute kidney injury was highest in the AoS group (p = 0.03). In multivariable logistic regression, CABG + Valve surgery (odds ratio (OR) 4.20, 95% confidence interval 1.30-13.6, p = 0.02) and lactate level at ECLS initiation (OR, 1.17; 95% CI, 1.06-1.29; p < 0.01) were independently associated with mortality. CONCLUSIONS: We demonstrate that indications, management, and outcomes of V-A ECLS for PCS vary by type of indexed cardiovascular surgery.

Outcome of extracorporeal membrane oxygenation support among children with methicillin-resistant Staphylococcus aureus infection: A single-center experience.

Introduction: The use of extracorporeal membrane oxygenation (ECMO) in children continues to increase nationally, including patients with methicillin-resistant Staphylococcus aureus (MRSA) infection. Survival of pediatric patients with MRSA sepsis has not improved over the last 20 years. We sought to review our institutional experience and outcomes of ECMO support among children with MRSA infection.Methods: Children aged 0-19 years who received ECMO support from October 2014 to June 2021 were reviewed retrospectively. Patients with laboratory confirmed MRSA infections were identified.Results: Out of 88 unique pediatric patients requiring ECMO support, eight patients had documented MRSA infections. The duration of mechanical ventilation prior to ECMO initiation was an average of seven days (range 0.7 to 21.8 days). The median ECMO duration was 648.1 h (range 15.5 to 1580.5 h). Five patients were successfully decannulated; however, only two patients survived to discharge. The two surviving patients were both cannulated via VV-ECMO. Mechanical ventilation prior to ECMO was 4.5 and 21.8 days in these cases with run durations of 18.9 and 29.9 days, respectively.Conclusions: Our institutional survival of patients with MRSA on ECMO is lower than what has been reported in recent database studies, but notably, 62.5% were successfully decannulated. While both surviving patients were supported with VV-ECMO, there was no other clear trend in factors that contributed to survival. MRSA continues to be a source of significant morbidity and mortality among pediatric patients. On-going investigation of outcomes and factors contributing to survival in patients with MRSA infection on ECMO is warranted.

A training programme for novice extracorporeal resuscitation providers.

Introduction: The use of extracorporeal cardiopulmonary resuscitation (ECPR) for refractory cardiac arrest is increasing globally. However, providing equity of access to all patients is challenging, and to date, access has been limited to inner city areas surrounding major hospitals. To increase the availability of ECPR in our jurisdiction, we sought to train pre-hospital physicians with no experience in extracorporeal membrane oxygenation cardiopulmonary resuscitation (ECPR). To enable this, we sort to develop and teach a syllabus that would provide novice ECPR providers the skill to perform ECPR safely and effectively in the pre-hospital environment. Methods: This training programme consisted of 11 pre-hospital physicians and six critical care paramedics. All participants had no prior hospital experience instituting or managing ECPR patients. The training programme was multimodal utilising a porcine model of heart failure to teach time pressured dynamic physiological troubleshooting, cadaver labs to teach cannulation, didactic teaching and simulation. Key knowledge and skill domains were identified. Each learning framework was built upon with a final focus on integrating all skill domains required to successfully initiate ECPR. Results: The training program was completed from February 2022 to August 2023. Knowledge progression was assessed at key stages via written and practical examination. Each participant demonstrated clear knowledge and skill progression at the key stages of the training programme. At the end of the training programme, participants met the pre-defined standards to progress to ECPR provision in the pre-hospital environment. Conclusion: We present a training program for novice ECPR providers performing ECPR in the pre-hospital setting. The outcomes of this training program can provide a training framework for both novices, low volume ECMO centres and pre-hospital clinicians.

Comparative efficacy of neuromodulation and structured exercise program on pain and muscle oxygenation in fibromyalgia patients: a randomized crossover study.

Introduction: This study investigates the comparative efficacy of neuromodulation therapy using the EXOPULSE Mollii Suit and a structured exercise program in pain modulation and muscle oxygenation in Fibromyalgia patients. Methods: A randomized, crossover, longitudinal, and experimental study design was employed, involving 10 female Fibromyalgia patients. Participants were subjected to two distinct treatment modalities: neuromodulation therapy with the EXOPULSE Mollii Suit and a strength-based High-Intensity Interval Training (HIIT) exercise program, each conducted over 16 sessions. Outcome measures included pain severity, assessed using the Numeric Rating Scale (NRS), and muscle oxygenation variables measured via Near-Infrared Spectroscopy (NIRS). Results: Both interventions demonstrated significant reductions in NRS scores and improvements in muscle oxygenation. However, the exercise program yielded more pronounced long term basal adaptations in muscle oxygenation compared to the neuromodulation therapy. Discussion: The findings underscore the potential of integrating non-pharmacological treatments, particularly structured exercise programs, in managing Fibromyalgia. While neuromodulation therapy presents a viable alternative, the exercise regimen's capacity to induce basal muscle oxygenation adaptations suggests its superiority in addressing the complex symptoms of Fibromyalgia. Furthermore, these therapeutic approaches may enhance patients' vocational values and employability opportunities by improving their functional capabilities and overall quality of life.

Hypoxic ischemic encephalopathy (HIE).

Introduction: The morbidity and mortality of acute ischemic hypoxic encephalopathy in newborns have not been dramatically modified over the last 20 years. The purpose of this review is to describe the use of hyperbaric oxygenation therapy (HBOT) in the management of acute ischemic hypoxic encephalopathy in newborns. Methods: A review of the medical literature was conducted on the use of HBOT in the pathophysiology of this condition and its impact on outcomes of patients treated at an early stage. Results: When HBOT is administered promptly, it can promote the survival of the penumbra, modulate the cytokine storm, modify inflammatory cascades, restore mitochondrial function, inhibit apoptosis, reinstate cellular communication and cytoskeleton function, reinstall the functioning of the kinase system, reduce cytotoxic and tissue edema, promote microcirculation, and provide an antioxidant effect. All these secondary mechanisms aid in saving, rescuing, and protecting the marginal tissue. Conclusion: When used promptly, HBOT is a non-invasive adjunct treatment that can preserve the marginal tissue affected by ischemia, hypoxia, meet the metabolic needs of the penumbra, reduce inflammatory cascades, prevent the extension of the damaged tissue, and modulate ischemia-reperfusion injury.

Advanced magnetic resonance imaging in human placenta: insights into fetal growth restriction and congenital heart disease.

Placental function plays a crucial role in fetal development, as it serves as the primary interface for delivery of nutrients and oxygen from the mother to fetus. Magnetic resonance imaging (MRI) has significantly improved our ability to visualize and understand the placenta's complex structure and function. This review provides an up-to-date examination of the most common and novel placental MRI techniques. It will also discuss the clinical applications of MRI in diagnosing and monitoring placental insufficiency, as well as its implications for fetal growth restriction (FGR) and congenital heart disease (CHD). Ongoing research using multi-parametric MRI techniques aims to develop novel biomarkers and uncover the relationships between placental parameters and pre-onset diseased states, ultimately contributing to better maternal and fetal health outcomes, which is essential to better guide clinical judgement.

Copper-Catalyzed Aromatization-Driven Ring-Opening Amination and Oxygenation of Spiro Dihydroquinazolinones.

Mild and inexpensive copper-catalyzed aromatization-driven ring-opening amination and oxygenation of spiro dihydroquinazolinones are presented, respectively. These protocols provide facile and atom-economical access to the aminated and the carbonyl-containing quinazolin-4(3H)-ones in good yields with good functional group compatibility, which are difficult to obtain by conventional methods. Remarkably, a telescoped procedure involving the condensation and the ring-opening/functionalization for simple cycloalkanone was found to be accessible. Mechanistic studies suggest a radical pathway for this transformation.

Planned Venovenous-Extracorporeal Membrane Oxygenation as a Bridge to Orthotopic Liver Transplant Performed for Very Severe Hepatopulmonary Syndrome: A Case Report.

Concerns related to poor oxygenation in patients with severe hepatopulmonary syndrome (HPS) may be prohibitive when considering their candidacy for liver transplantation. Extracorporeal membrane oxygenation (ECMO) has been utilized in only a few case reports as a bridge to liver transplant in patients with severe respiratory failure. We report a case of a 66-year-old man with cirrhosis and very severe (arterial oxygen pressure (PaO2) < 50 mmHg) hepatopulmonary syndrome who underwent an orthotopic liver transplant with the planned use of venovenous-ECMO. Pre-transplant echocardiography demonstrated a small-trivial patent foramen ovale (PFO) but following the resolution of hepatopulmonary shunting after liver transplantation, the PFO size enlarged and contributed to a thromboembolic stroke. We conclude that well-selected patients with HPS could benefit from the use of planned venovenous-ECMO and that a small-trivial PFO seen in a patient with HPS may warrant intervention prior to transplantation.

Rod-Shaped Au@Ce Nano-Platforms for Enhancing Photodynamic Tumor Collaborative Therapy.

Tumor photodynamic therapy (PDT) relies on intratumoral free radicals, while the limited oxygen source and the depletion of tissue oxygen may exacerbate the hypoxia. As the treatment progresses, there will eventually be a problem of insufficient free radicals. Here, it is found that Au@CeO2 nano-rods (Au@Ce NRs), assembled by gold nano-rods (Au NRs) and ceria nanoparticles (CeO2 NPs), can efficaciously absorb near-infrared light (NIR) to promote the release of oxygen and free radicals. Au@Ce NRs exhibit a higher proportion of Ce3+ (Ce2O3) after oxygen release, while Ce3+ is subsequently oxidized to Ce4+ (CeO2) by trace H2O2. Interestingly, Au@Ce NRs re-oxidized by trace H2O2 can re-releasing oxygen and free radicals again upon NIR treatment, achieving oxygenation/oxygen evolution, similar to charging/discharging. This loop maximizes the conversion of limited oxygen source into highly cytotoxic free radicals. As a result, when B16-F10 cells are treated by NIR/Au@Ce NRs, more tumor cells undergo apoptosis, consistent with the higher level of free radicals. Importantly, NIR/Au@Ce NRs successfully suppresses tumor growth and promotes the generation of epidermal collagen fibers in the transplanted tumor model. Therefore, the rod-shaped Au@Ce NRs provide an ideal platform for maximizing the utilization of intratumoral oxygen sources and improving the treatment of melanoma.

Definition and management of right ventricular injury in adult patients receiving extracorporeal membrane oxygenation for respiratory support using the Delphi method: a PRORVnet study. Expert position statements.

PURPOSE: Veno-venous extracorporeal membrane oxygenation (VV-ECMO) is an integral part of the management algorithm of patients with severe respiratory failure refractory to evidence-based conventional treatments. Right ventricular injury (RVI) pertaining to abnormalities in the dimensions and/or function of the right ventricle (RV) in the context of VV-ECMO significantly influences mortality. However, in the absence of a universally accepted RVI definition and evidence-based guidance for the management of RVI in this very high-risk patient cohort, variations in clinical practice continue to exist. METHODS: Following a systematic search of the literature, an international Steering Committee consisting of eight healthcare professionals involved in the management of patients receiving ECMO identified domains and knowledge gaps pertaining to RVI definition and management where the evidence is limited or ambiguous. Using a Delphi process, an international panel of 52 Experts developed Expert position statements in those areas. The process also conferred RV-centric overarching open questions for future research. Consensus was defined as achieved when 70% or more of the Experts agreed or disagreed on a Likert-scale statement or when 80% or more of the Experts agreed on a particular option in multiple-choice questions. RESULTS: The Delphi process was conducted through four rounds and consensus was achieved on 31 (89%) of 35 statements from which 24 Expert position statements were derived. Expert position statements provided recommendations for RVI nomenclature in the setting of VV-ECMO, a multi-modal diagnostic approach to RVI, the timing and parameters of diagnostic echocardiography, and VV-ECMO settings during RVI assessment and management. Consensus was not reached on RV-protective driving pressure thresholds or the effect of prone positioning on patient-centric outcomes. CONCLUSION: The proposed definition of RVI in the context of VV-ECMO needs to be validated through a systematic aggregation of data across studies. Until further evidence emerges, the Expert position statements can guide informed decision-making in the management of these patients.

Effect of Atrial Septostomy on Left Ventricular Function in Pediatric Dilated Cardiomyopathy Requiring ECMO.

Balloon atrial septostomy (BAS) reduces left ventricular (LV) hypertension during extracorporeal membrane oxygenation (ECMO). However, the acute effect of BAS on LV function as measured by echocardiography is unknown. This was a Retrospective analysis of clinical outcome, LV dimensions, and LV function in dilated cardiomyopathy patients 0-18 years old who underwent BAS on ECMO. In 13 patients with median (IQR) age of 2.3 (0.6-10.9) years, there were no differences in clinical markers of cardiac output at intervals between 12 h before and 6 days after BAS. In addition, BAS was associated with a low rate of periprocedural complications (0.0%), acute kidney injury (7.7%), and worsening radiographic pulmonary vascular congestion (30.7%). There was a significant worsening in LV end systolic diameter (LVIDs; 3.6 [2.9-4.8] cm vs 4.2 [3.2-5.6] cm vs 3.3 [2.6-4.6] cm, p = 0.025), LV end systolic posterior wall thickness (LVPWs; 0.7 [0.5-0.9] cm vs 0.6 [0.5-0.9] cm vs 0.8 [0.6-1.2] cm, p = 0.038), fractional shortening (FS; 17.6% [8.4-20.4%] vs 6.3% [2.0-9.9%] vs 13.2% [3.6-23.4%], p = 0.013), and ejection fraction (EF; 13.1% [8.7-18.9%] vs 5.3% [2.5-11.1%] vs 9.2% [6.0-16.3%], p = 0.039) following BAS that improved in approximately 1 week. There were no differences in LV global longitudinal strain following BAS. We conclude that BAS was associated with low procedural and clinical adverse event rates in our cohort. The worsening LVIDs, LVPWs, FS, and EF seen immediately after the procedure suggests that BAS causes altered loading conditions affecting LV function in pediatric patients with dilated cardiomyopathy requiring ECMO.

Hyperfibrinolysis: potential guidance for decision-making to avoid futile extracorporeal cardiopulmonary resuscitation.

Out-of-hospital cardiac arrest (OHCA) is associated with very poor outcomes. Extracorporeal cardiopulmonary resuscitation (eCPR) for selected patients is a potential therapeutic option for refractory cardiac arrest. However, randomised controlled studies applying eCPR after refractory OHCA have demonstrated conflicting results regarding survival and good functional neurological outcomes. eCPR is an invasive, labour-intensive, and expensive therapeutic approach with associated side-effects. A rapid monitoring device would be valuable in facilitating selection of appropriate patients for this expensive and complex treatment. To this end, rapid diagnosis of hyperfibrinolysis, or premature clot dissolution, diagnosed by viscoelastic testing might represent a feasible option. Hyperfibrinolysis is an evolutionary response to low or no-flow states. Studies in trauma patients demonstrate a high mortality rate in those with established hyperfibrinolysis upon emergency room admission. Similar findings have now been reported for the first time in OHCA patients. Hyperfibrinolysis upon admission diagnosed by rotational thromboelastometry was strongly associated with mortality and poor neurological outcomes in a small cohort of patients treated with extracorporeal membrane oxygenation.

Iatrogenic HLH.

Hemophagocytic lymphohistiocytosis (HLH) can be categorized as either primary (familial, generally occurring in infants) or secondary (sHLH, occurring at any age in association with a variety of conditions) and is mainly triggered by infections, autoimmune diseases, and malignant conditions. Our understanding of the pathophysiology of sHLH is still evolving, and among the causes and associations with the syndrome, those putatively associated with iatrogenic causes remain among the most poorly understood due to the rarity of these entities and the multiple confounders so often present in the patients in whom they are reported. Herein, we present a review of the literature to describe the diagnostic and therapeutic challenges of sHLH associated with iatrogenic causes and discuss some of the challenges and future directions in our efforts to better understand these complex conditions for the advancement of patient outcomes.

Acute kidney injury as a prognostic predictor of in-hospital mortality and neurological outcomes in patients after extracorporeal cardiopulmonary resuscitation.

INTRODUCTION: Extracorporeal cardiopulmonary resuscitation (ECPR) is increasingly being applied to patients with refractory cardiac arrest, but the survival rate to hospital discharge is only approximately 29%. Because ECPR requires intensive resources, it is important to predict outcomes. We therefore investigated the prognostic association between acute kidney injury (AKI) and ECPR to confirm the performance of AKI as a prognostic predictor of in-hospital mortality and neurological outcomes in ECPR. METHODS: We conducted a retrospective observational study on patients undergoing ECPR for cardiac etiology at Chonnam National University Hospital from 2015 to 2021. The group diagnosed with AKI in any KDIGO category within the first 48 h after ECPR was compared to that without AKI, and the primary outcome of the study was in-hospital mortality. RESULTS: Of 138 enrolled patients, 83 were studied. Hospital mortality occurred in 49 patients (59%), and 55 (66.3%) showed poor neurological outcomes. The AKI group displayed significantly elevated in-hospital mortality (77.8% vs 24.1%) and poor neurological outcomes (81.5% vs 37.9%) compared to the non-AKI group (p < 0.001). Regression analysis showed that AKI was associated with significantly higher rates of both in-hospital mortality (odds ratio (OR) range 10.75-12.88) and neurologic outcomes (OR range 5.9-6.22). CONCLUSIONS: There was a significant association of AKI with both in-hospital mortality and poor neurologic outcome in patients after ECPR, and AKI can be used as an early prognostic predictor in these patients.

Response of Staphylococcus aureus physiology and Agr quorum sensing to low-shear modeled microgravity.

Staphylococcus aureus is commonly isolated from astronauts returning from spaceflight. Previous analysis of omics data from S. aureus low Earth orbit cultures indicated significantly increased expression of the Agr quorum sensing system and its downstream targets in spaceflight samples compared to ground controls. In this current study, the rotary cell culture system (RCCS) was used to investigate the effect of low-shear modeled microgravity (LSMMG) on S. aureus physiology and Agr activity. When cultured in the same growth medium and temperature as the previous spaceflight experiment, S. aureus LSMMG cultures exhibited decreased agr expression and altered growth compared to normal gravity control cultures, which are typically oriented with oxygenation membrane on the bottom of the high aspect rotating vessel (HARV). When S. aureus was grown in an inverted gravity control orientation (oxygenation membrane on top of the HARV), reduced Agr activity was observed relative to both traditional control and LSMMG cultures, signifying that oxygen availability may affect the observed differences in Agr activity. Metabolite assays revealed increased lactate and decreased acetate excretion in both LSMMG and inverted control cultures. Secretomics analysis of LSMMG, control, and inverted control HARV culture supernatants corroborated these results, with inverted and LSMMG cultures exhibiting a decreased abundance of Agr-regulated virulence factors and an increased abundance of proteins expressed in low-oxygen conditions. Collectively, these studies suggest that the orientation of the HARV oxygenation membrane can affect S. aureus physiology and Agr quorum sensing in the RCCS, a variable that should be considered when interpreting data using this ground-based microgravity model.IMPORTANCES. aureus is commonly isolated from astronauts returning from spaceflight and from surfaces within human-inhabited closed environments such as spacecraft. Astronaut health and immune function are significantly altered in spaceflight. Therefore, elucidating the effects of microgravity on S. aureus physiology is critical for assessing its pathogenic potential during long-term human space habitation. These results also highlight the necessity of eliminating potential confounding factors when comparing simulated microgravity model data with actual spaceflight experiments.

Monitoring lung and cerebral oxygenation using near-infrared spectroscopy in preterm infants during kangaroo mother care.

Lung function has never been assessed during kangaroo mother care (KMC) in preterm infants. We measured lung (rSO2L) and cerebral (rSO2C) oxygenation by near-infrared spectroscopy (NIRS) in infants born at less than 32 weeks of gestation or weighing ≤ 1500 g during KMC. rSO2L, rSO2C, and pulmonary (FOEL) and cerebral (FOEC) tissue oxygen extraction fraction were measured in 20 preterm infants before, during, and after a 2-h period of KMC at a mean postnatal age of 36 ± 21 days of life. We found that rSO2L, rSO2C, FOEL, and FOEC did not change in our patients. After 120 min of KMC, rSO2L was lower (71.3 ± 1.4 vs. 76.7 ± 4.6%; P = 0.012) in infants with BPD (n = 6; 30%) than in infants without BPD (n = 14 = 60%), while FOEL was higher (0.26 ± 0.02 vs. 0.20 ± 0.05; P = 0.012).Conclusion: Cerebral and lung oxygenation did not change in preterm infants during KMC. A transient decrease in lung oxygenation was offset by the increase in oxygen extraction, but these changes were clinically insignificant. These results confirm the safety of KMC in preterm infants who are in stable clinical conditions. What is Known • Kangaroo mother care (KMC) is widely used to improve the care of preterm newborns since it improves their outcome. • KMC is safe as patients' vital parameters, are not negatively affected, but lung function has never been directly assessed. What is New • Cerebral and lung oxygenation measured by near-infrared spectroscopy did not change during KMC. • A transient decrease in lung oxygenation compensated for by the increase in oxygen extraction occurred only in infants with BPD, but these changes were clinically insignificant.