Respiratory Mode Research Articles

Risk Factors for Hearing Screen Failure in a Single Family Room Neonatal Intensive Care Unit.

To determine hearing screen outcomes and identify clinical and environmental risk factors for hearing screen failure in very preterm infants at a level IV single family room (SFR) neonatal intensive care unit (NICU). We conducted a retrospective study of infants <33wks gestational age admitted to a level IV SFR NICU who survived to discharge and had automated auditory brainstem response results available. Demographics, antenatal and postnatal factors, and respiratory support modes and their duration were collected from the electronic medical record. Of 425 eligible infants with documented hearing screen results, 353 (83%) passed and 72 (17%) failed the hearing screen [unilateral, N= 44 (61%); bilateral, N= 28 (39%)]. Compared to infants who passed the hearing screen, infants with hearing screen failure were lower gestational age and birthweight, male sex, were screened at later postnatal and postmenstrual ages, had lower 1 and 5 min Apgar scores, longer duration of furosemide therapy, early hypotension, IVH≥ Grade 3, and BPD at 36 weeks PMA. Infants with hearing screen failure experienced longer exposures to invasive and non-invasive respiratory support. Heated, humidified, high flow nasal cannula >2LPM exposure was significantly longer in infants with bilateral hearing screen failure (18.4±18.4 d) compared to duration in infants who passed (7.4±12.8 d) and those with unilateral failure (9±13 d), (mean ± SD, p<0.001). In the final logistic model, IVH ≥Grade 3 (OR 3.22, 95% CI 1.15-8.98, p=0.026) and BPD (OR 2.27, 95% CI 1.25-4.11, p=0.007) were the factors with greatest risk for hearing screen failure. We speculate that the association of BPD with hearing screen failure may be mediated, in part, by chronic noise exposure, including from respiratory support devices. Attention to hearing protection in at-risk infants during respiratory support may mitigate the risk of hearing loss.

Comparison of Effects between Nasal Bi-Level Positive Airway Pressure and Nasal Synchronized Intermittent Mandatory Ventilation in Neonatal Respiratory Distress Syndrome

Aims/Background Neonatal respiratory distress syndrome (NRDS) is characterized by progressive aggravation and rapid progression of respiratory distress, with a high incidence rate among premature infants. If left untreated, NRDS results in a poor prognosis. In recent years, various respiratory support modalities have received extensive attention in clinical practice. The therapeutic effect of different respiratory support modes on NRDS has gradually become the focus of clinical research. The aim of this study was to explore the therapeutic effects of nasal bi-level positive airway pressure (nBiPAP) and nasal synchronized intermittent mandatory ventilation (nSIMV) on NRDS. Methods This study retrospectively analyzed the clinical data of 157 newborns with NRDS in the Mudanjiang Medical University Affiliated Second Hospital from January 2021 to December 2023, finally including 153 cases after excluding 4 cases with missing clinical data. According to the non-invasive ventilation method, these newborns were categorized into a nBiPAP group (receiving nBiPAP treatment, n = 77) and an nSIMV group (receiving nSIMV treatment, n = 76). The blood gas indices, using time of ventilator, hospitalization time, therapeutic effects, and incidence of complications were compared between the two groups. Results The PaCO2, PaO2, and pH levels in the nBiPAP group were basically consistent with those in the nSIMV group before and after treatment (p &gt; 0.05). The use time of ventilator, hospitalization time, and therapeutic effects in the nBiPAP group were similar to those in the nSIMV group (p &gt; 0.05). Additionally, both groups demonstrated no significant difference in the incidence of complications such as intraventricular hemorrhage, apnea, necrotizing enterocolitis, and feeding intolerance (p &gt; 0.05). The incidence rates of ventilator-associated lung injury and neonatal bronchopulmonary dysplasia in the nBiPAP group were lower than those in the nSIMV group, with a significant difference (p &lt; 0.05). Conclusion Both nBiPAP and nSIMV have shown good effects in treating NRDS, with nBiPAP showing a significant advantage in reducing the incidence rates of complications such as ventilator-associated lung injury and neonatal bronchopulmonary dysplasia.

75 Lung ultrasound severity scores and its utility in predicting success of weaning off respiratory support in neonates born preterm

Abstract Background Preterm infants often require respiratory support in the newborn intensive care unit. Complete trial off around 30-34 weeks post-menstrual age (PMA) is by trial and error based on clinical and physiological variables. Lung ultrasound (LUS) is a reliable adjunct in the diagnosis and management of most neonatal lung conditions. However, its utility in accessing readiness for successful weaning off respiratory pressure support in preterm neonates has not been explored. Objectives To determine the utility of LUS severity score (LUS-sc) in predicting successful weaning off of respiratory pressure support after 32weeks CGA in neonates born ≤32 weeks gestational age (GA). Design/Methods Prospective cohort study involving preterm neonates born ≤32 weeks needing any respiratory pressure support modes, admitted to a single tertiary care center in Canada between Sept 2022-Sept 2023. Eligible neonates were assessed by LUS at two time points- LUS1 at 30-30 + 6 weeks for those born &amp;lt;30weeks GA and between 48-72hours of life for those born at 30-32 + 6 weeks GA; LUS2 within 12hours prior to trial off respiratory pressure support to room air or low flow after 32weeks PMA. LUS were scored for disease severity by two independent reviewers using the LUS-sc by Brat et al. Receiver operator characteristics (ROC) curves analyzed the reliability of LUS-sc to predict the successful cessation of respiratory pressure support to room air or low flow post LUS2. Results Of 50 preterm neonates included in the study, 32 (64%) were successfully weaned from pressure support after LUS2 at a mean (SD) GA of 33.03 (0.29). The mean (SD) GA at birth was 28.78 (0.46) in the successful group and 27.78 (0.62) in the unsuccessful group (p=0.197). The mean (SD) LUS-sc for LUS2 at which cessation of support was possible was significantly lower from those who failed [6.95(0.33) vs 8.69(0.55), p=0.006] (Table 1). The ROC curve (Figure 1) showed AUC of 0.717 (95%CI=0.56-0.86), for a cut-off of LUS-sc of 7.75, with sensitivity of 0.75 (95%CI=0.60-0.90) and specificity of 0.61 (95%CI=0.38-0.84). Independent of GA at birth and at respiratory pressure support trial off, LUS-sc ≤8 was associated with an increased odd of cessation of support by 9.0 (95%CI=1.9-42.6), p=0.005, and each additional week of GA at first trial off increased the odds of cessation by 2.2 (95%CI=1.1-4.4), p=0.031. Conclusion LUS is a reliable tool to assess readiness for successful non-invasive respiratory pressure support trial off. A LUS-sc ≤8 was associated with higher successful weaning off of non-invasive pressure support after 32weeks GA.

Low-dose hexavalent chromium induces mitophagy in rat liver via the AMPK-related PINK1/Parkin signaling pathway.

Hexavalent chromium (Cr(VI)) is a hazardous metallic compound commonly used in industrial processes. The liver, responsible for metabolism and detoxification, is the main target organ of Cr(VI). Toxicity experiments were performed to investigate the impacts of low-dose exposure to Cr(VI) on rat livers. It was revealed that exposure of 0.05 mg/kg potassium dichromate (K2Cr2O7) and 0.25 mg/kg K2Cr2O7 notably increased malondialdehyde (MDA) levels and the expressions of P-AMPK, P-ULK, PINK1, P-Parkin, and LC3II/LC3I, and significantly reduced SOD activity and P-mTOR and P62 expression levels in liver. Electron microscopy showed that CR(VI) exposure significantly increased mitophagy and the destruction of mitochondrial structure. This study simulates the respiratory exposure mode of CR(VI) workers through intratracheal instillation of CR(VI) in rats. It confirms that autophagy in hepatocytes is induced by low concentrations of CR(VI) and suggest that the liver damage caused by CR(VI) may be associated with the AMPK-related PINK/Parkin signaling pathway.

Noninvasive high-frequency oscillation ventilation as post- extubation respiratory support in neonates: Systematic review and meta-analysis.

Noninvasive High-Frequency Oscillatory Ventilation (NHFOV) is increasingly being adopted to reduce the need for invasive ventilation after extubation. To evaluate the benefits and harms of NHFOV as post-extubation respiratory support in newborns compared to other non-invasive respiratory support modes. We included randomized controlled trials comparing NHFOV with other non-invasive modes post-extubation in newborns. Data sources were MEDLINE (via Pubmed), Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, WHO international clinical trials registry platform and Clinical Trial Registry, forward and backward citation search. Methodological quality of studies was assessed by Cochrane's Risk of Bias tool 1.0. This systematic review included 21 studies and 3294 participants, the majority of whom were preterm. NHFOV compared to nasal continuous positive airway pressure (NCPAP) reduced reintubation within seven days (RR 0.34, 95% CI 0.22 to 0.53) after extubation. It also reduced extubation failure (RR 0.39, 95% CI 0.30 to 0.51) and reintubation within 72 hrs (RR 0.40, 95% CI 0.31 to 0.53), bronchopulmonary dysplasia (RR 0.59, 95% CI 0.37 to 0.94) and pulmonary air leak (RR 0.46, 95% CI 0.27 to 0.79) compared to NCPAP. The rate of reintubation within seven days (RR 0.62, 95% CI 0.18 to 2.14) was similar whereas extubation failure (RR 0.65, 95% CI 0.50 to 0.83) and reintubation (RR 0.68, 95% CI 0.52 to 0.89) within 72 hrs were lower in NHFOV group compared to nasal intermittent positive pressure ventilation. There was no effect on other outcomes. Overall quality of the evidence was low to very low in both comparisons. NHFOV may reduce the rate of reintubation and extubation failure post-extubation without increasing complications. Majority of the trials were exclusively done in preterm neonates. Further research with high methodological quality is warranted.

Carbon Nanotube Immunotoxicity in Alveolar Epithelial Type II Cells Is Mediated by Physical Contact-Independent Cell-Cell Interaction with Macrophages as Demonstrated in an Optimized Air-Liquid Interface (ALI) Coculture Model.

There is a need for the assessment of respiratory hazard potential and mode of action of carbon nanotubes (CNTs) before their approval for technological or medical applications. In CNT-exposed lungs, both alveolar macrophages (MФs), which phagocytose CNTs, and alveolar epithelial type II cells (AECII cells), which show tissue injury, are impacted but cell-cell interactions between them and the impacted mechanisms are unclear. To investigate this, we first optimized an air-liquid interface (ALI) transwell coculture of human AECII cell line A549 (upper chamber) and human monocyte cell line THP-1 derived macrophages (lower chamber) in a 12-well culture by exposing macrophages to CNTs at varying doses (5-60 ng/well) for 12-48 h and measuring the epithelial response markers for cell differentiation/maturation (proSP-C), proliferation (Ki-67), and inflammation (IL-1β). In optimal ALI epithelial-macrophage coculture (3:1 ratio), expression of Ki-67 in AECII cells showed dose dependence, peaking at 15 ng/well CNT dose; the Ki-67 and IL-1β responses were detectable within 12 h, peaking at 24-36 h in a time-course. Using the optimized ALI transwell coculture set up with and without macrophages, we demonstrated that direct interaction between CNTs and MФs, but not a physical cell-cell contact between MФ and AECII cells, was essential for inducing immunotoxicity (proliferative and inflammatory responses) in the AECII cells.

Incidence of neonatal respiratory morbidity after vaginal and caesarean delivery in the late-preterm and term period - a retrospective cohort study.

Respiratory distress syndrome is a leading cause of neonatal intensive care unit admissions for late preterm (34-36 weeks gestational age) and term infants (37-41 weeks). The risk for respiratory morbidity appears to increase after an elective caesarean delivery and might be reduced after antenatal corticosteroids. However, before considering antenatal corticosteroids for women at high risk of preterm birth after 34 weeks, the incidence of respiratory distress syndrome and the effect of delivery mode on this incidence requires further evaluation. Therefore, this study aimed to investigate the relationship between respiratory distress syndrome incidence and delivery mode in late preterm and term infants. In this retrospective cohort study, the clinical databases of the University Hospitals of Zurich and Basel were queried regarding all live births between 34 + 0 and 41 + 6 weeks. Neonatal intensive care unit admissions due to respiratory distress syndrome were determined and analysed in regard to the following delivery modes: spontaneous vaginal, operative vaginal, elective caesarean, secondary caesarean and emergency caesarean. After excluding malformations (n = 889) and incomplete or inconclusive data (n = 383), 37,110 infants out of 38,382 were evaluated. Of these, 5.34% (n = 1980) were admitted to a neonatal intensive care unit for respiratory distress syndrome. Regardless of gestational age, respiratory distress syndrome in infants after spontaneous vaginal delivery was 2.92%; for operative vaginal delivery, it was 4.02%; after elective caesarean delivery it was 8.98%; following secondary caesarean delivery, it was 8.45%, and after an emergency caesarean it was 13.3%. The risk of respiratory distress syndrome was higher after an elective caesarean compared to spontaneous vaginal delivery, with an odds ratio (OR), adjusted for gestational age, of 2.31 (95% CI 1.49-3.56) at 34 weeks, OR 5.61 (95% CI 3.39-9.3) at 35 weeks, OR 1.5 (95% CI 0.95-2.38) at 36 weeks, OR 3.28 (95% CI 1.95-5.54) at 37 weeks and OR 2.51 (95% CI 1.65-3.81) at 38 weeks. At 39 weeks, there was no significant difference between the risk of respiratory distress syndrome after an elective caesarean vs. spontaneous vaginal delivery. Over the study period, gestational age at elective caesarean delivery remained stable at 39.3 ± 1.65 weeks. The incidence of respiratory distress syndrome following an elective caesarean is up to threefold higher in infants born with less than 39 weeks gestational age compared to those born by spontaneous vaginal delivery. Therefore - and whenever possible - an elective caesarean delivery should be planned after 38 completed weeks to minimise the risk of respiratory morbidity in neonates.

Nasal High-Frequency Oscillatory Ventilation Use in Romanian Neonatal Intensive Care Units-The Results of a Recent Survey.

Nasal high-frequency oscillatory ventilation (nHFOV) has emerged as an effective initial and rescue noninvasive respiratory support mode for preterm infants with respiratory distress syndrome (RDS); however, little is known about nHFOV use in Romanian neonatal intensive care units (NICUs). We aimed to identify the usage extent and clinical application of nHFOV in Romania. A structured web-based questionnaire was designed to find the rate of nHFOV use and knowledge of this new method of noninvasive respiratory support in Romanian level III NICUs. Using multiple-choice, open-ended, and yes/no questions, we collected information on the NICU's size, noninvasive respiratory support modes used, nHFOV use, indications, settings, nasal interfaces, secondary effects, and equipment used. Descriptive statistics and comparisons were performed using IBM SPSS Statistics 26.0. A total of 21/23 (91.3%) leaders from level III NICUs (median [IQR] number of beds of 10 [10-17.5]) responded to the survey. The most frequently used noninvasive ventilation modes were CPAP mode on mechanical ventilators (76.2%), followed by NIPPV (76.2%); heated, humidified high-flow nasal cannula (HHHFNC) (61.9%); and nHFOV (11/21 units; 52.4%). A total of 5/11 units reported frequent nHFOV use (in two or more newborns/month) in both term and preterm infants. The main indications reported for nHFOV use were CPAP failure (90.9%), hypercapnia (81.8%), and bronchopulmonary dysplasia (72.7%). Face/nasal masks and short binasal prongs are the most commonly used nasal interfaces (90.9% and 72.7%, respectively). Air leaks at the interface level (90.9%), thick secretions (81.8%), and airway obstruction (63.6%) were the most frequently mentioned adverse effects of nHFOV. Only three of the NICUs had a written protocol for nHFOV use. Most units not yet using nHFOV cited lack of equipment, experience, training, or insufficient information and evidence for the clinical use and outcome of nHFOV use in neonates as the main reasons for not implementing this noninvasive respiratory mode. Our survey showed that nHFOV is already used in more than half of the Romanian level III NICUs to support term and preterm infants with respiratory distress despite a lack of consensus regarding indications and settings during nHFOV.

Effectiveness of dolutegravir in moderate severity COVID-19 patients: A single-center, randomized, double-blind, placebo-controlled trial

Introduction: Drug repurposing as a low-cost, time-saving, and often less risky strategy has been attractive for the treatment of coronavirus disease 2019 (COVID-19) during the pandemic. This trial aimed to evaluate the effectiveness of dolutegravir, an HIV-1 integrase inhibitor, in admitted patients with moderate COVID-19. Methods: This study was a randomized, double-blind, placebo-controlled clinical trial assessing the efficacy of dolutegravir in adults admitted to a hospital in Ghaemshahr, Mazandaran Province, Iran. Patients aged 18-80 years with early symptoms of moderate COVID-19, which was confirmed based on reverse transcription polymerase chain reaction (RT-PCR) and/or chest computed tomography (CT) scan, were considered to be included in this study. Patients were randomly assigned in a 1:1 ratio to receive 50 mg dolutegravir plus the standard treatment regimen or the same value of placebo plus the standard treatment regimen, daily for 7 days. The standard treatment regimen was remdesivir 200 mg on day 1 followed by 100 mg for five days or until discharge. The primary endpoint was recovery 10 days after the beginning of the study. Results: Between August 22 and October 23, 2021, of 120 patients who were enrolled, 93 patients were randomly assigned to receive 50 mg dolutegravir (n = 46) or the placebo regimen (n = 47). No significant difference was observed between the two intervention groups based on the obtained results including frequency of respiratory modes during the first five days of admission, respiratory rate, and O2 saturation during six time periods. Conclusion: The results showed that in adult patients admitted to the hospital with moderate COVID-19, treatment with dolutegravir was not associated with improvement in clinical recovery. Larger randomized trials are required to provide more robust evidence about the effectiveness of dolutegravir.

Pediatric Respiratory Syncytial Virus Hospitalizations and Respiratory Support After the COVID-19 Pandemic

After the COVID-19 pandemic, there was a surge of pediatric respiratory syncytial virus (RSV) infections, but national data on hospitalization and intensive care unit use and advanced respiratory support modalities have not been reported. To analyze demographics, respiratory support modes, and clinical outcomes of children with RSV infections at tertiary pediatric hospitals from 2017 to 2023. This cross-sectional study evaluated children from 48 freestanding US children's hospitals registered in the Pediatric Health Information System (PHIS) database. Patients 5 years or younger with RSV from July 1, 2017, to June 30, 2023, were included. Each season was defined from July 1 to June 30. Prepandemic RSV seasons included 2017 to 2018, 2018 to 2019, and 2019 to 2020. The postpandemic season was delineated as 2022 to 2023. Hospital presentation with RSV infection. Data on emergency department presentations, hospital or intensive care unit admission and length of stay, demographics, respiratory support use, mortality, and cardiopulmonary resuscitation were analyzed. Postpandemic season data were compared with prepandemic seasonal averages. A total of 288 816 children aged 5 years or younger (median [IQR] age, 8.9 [3.3-21.5] months; 159 348 [55.2%] male) presented to 48 US children's hospitals with RSV from July 1, 2017, to June 30, 2023. Respiratory syncytial virus hospital presentations increased from 39 698 before the COVID-19 pandemic to 94 347 after the pandemic (P < .001), with 86.7% more hospitalizations than before the pandemic (50 619 vs 27 114; P < .001). In 2022 to 2023, children were older (median [IQR] age, 11.3 [4.1-26.6] months vs 6.8 [2.6-16.8] months; P < .001) and had fewer comorbidities (17.6% vs 21.8% of hospitalized patients; P < .001) than during prepandemic seasons. Advanced respiratory support use increased 70.1% in 2022 to 2023 (9094 vs 5340; P < .001), and children requiring high-flow nasal cannula (HFNC) or noninvasive ventilation (NIV) were older than during prepandemic seasons (median [IQR] age for HFNC, 6.9 [2.7-16.0] months vs 4.6 [2.0-11.7] months; for NIV, 6.0 [2.1-16.5] months vs 4.3 [1.9-11.9] months). Comorbid conditions were less frequent after the pandemic across all respiratory support modalities (HFNC, 14.9% vs 19.1%, NIV, 22.0% vs 28.5%, invasive mechanical ventilation, 30.5% vs 38.0%; P < .001). This cross-sectional study identified a postpandemic pediatric RSV surge that resulted in markedly increased hospital volumes and advanced respiratory support needs in older children with fewer comorbidities than prepandemic seasons. These clinical trends may inform novel vaccine allocation to reduce the overall burden during future RSV seasons.

Amphibians Exhibit Extremely High Hydric Costs of Respiration.

Terrestrial environments pose many challenges to organisms, but perhaps one of the greatest is the need to breathe while maintaining water balance. Breathing air requires thin, moist respiratory surfaces, and thus the conditions necessary for gas exchange are also responsible for high rates of water loss that lead to desiccation. Across the diversity of terrestrial life, water loss acts as a universal cost of gas exchange and thus imposes limits on respiration. Amphibians are known for being vulnerable to rapid desiccation, in part because they rely on thin, permeable skin for cutaneous respiration. Yet, we have a limited understanding of the relationship between water loss and gas exchange within and among amphibian species. In this study, we evaluated the hydric costs of respiration in amphibians using the transpiration ratio, which is defined as the ratio of water loss (mol H2O d-1) to gas uptake (mol O2 d-1). A high ratio suggests greater hydric costs relative to the amount of gas uptake. We compared the transpiration ratio of amphibians with that of other terrestrial organisms to determine whether amphibians had greater hydric costs of gas uptake relative to plants, insects, birds, and mammals. We also evaluated the effects of temperature, humidity, and body mass on the transpiration ratio both within and among amphibian species. We found that hydric costs of respiration in amphibians were two to four orders of magnitude higher than the hydric costs of plants, insects, birds, and mammals. We also discovered that larger amphibians had lower hydric costs than smaller amphibians, at both the species- and individual-level. Amphibians also reduced the hydric costs of respiration at warm temperatures, potentially reflecting adaptive strategies to avoid dehydration while also meeting the demands of higher metabolic rates. Our results suggest that cutaneous respiration is an inefficient mode of respiration that produces the highest hydric costs of respiration yet to be measured in terrestrial plants and animals. Yet, amphibians largely avoid these costs by selecting aquatic or moist environments, which may facilitate more independent evolution of water loss and gas exchange.

From nasal respiration to brain dynamic.

While breathing is a vital, involuntary physiological function, the mode of respiration, particularly nasal breathing, exerts a profound influence on brain activity andcognitive processes. This review synthesizes existing research on the interactions between nasal respiration and the entrainment of oscillations across brain regions involved in cognition. The rhythmic activation of olfactory sensory neurons during nasal respiration is linked to oscillations in widespread brain regions, including the prefrontal cortex, entorhinal cortex, hippocampus, amygdala, and parietal cortex, as well as the piriform cortex. The phase-locking of neural oscillations to the respiratory cycle, through nasal breathing, enhances brain inter-regional communication and is associated with cognitive abilities like memory. Understanding the nasal breathing impact on brain networks offers opportunities to explore novel methods for targeting the olfactory pathway as a means to enhance emotional and cognitive functions.

Impact of hypoxia on glucose metabolism and hypoxia signaling pathways in juvenile horseshoe crabs Tachypleus tridentatus

Marine hypoxia poses a significant challenge in the contemporary marine environment. The horseshoe crab, an ancient benthic marine organism, is confronted with the potential threat of species extinction due to hypoxia, making it an ideal candidate for studying hypoxia tolerance mechanisms. In this experiment, juvenile Tachypleus tridentatus were subjected to a 21-day trial at DO:2 mg/L (hypoxia) and DO:6 mg/L conditions. The experimental timeline included a 14-day exposure phase followed by a 7-day recovery period. Sampling occurred on days 0, 7, 14, and 21, where the period from day 14 to day 21 corresponds to seven days of recuperation. Several enzymatic activities of important proteins throughout this investigation were evaluated, such as succinate dehydrogenase (SDH), phosphofructokinase (PFK), hexokinase (HK), lactate dehydrogenase (LDH), and pyruvate kinase (PK). Concurrently, the relative expression of hexokinase-1 (HK), hypoxia-inducible factor 1-alpha inhibitor (FIH), and hypoxia-inducible factor 1-alpha (HIF-1α), pyruvate dehydrogenase phosphatase (PDH), succinate dehydrogenase assembly factor 4 (SDH), and Glucose-6-phosphatase (G6Pase) were also investigated. These analyses aimed to elucidate alterations in the hypoxia signaling pathway and respiratory energy metabolism. It is revealed that juvenile T. tridentatus initiated the HIF pathway under hypoxic conditions, resulting in an upregulation of HIF-1α and FIH-1 gene expression, which in turn, influenced a shift in metabolic patterns. Particularly, the activity of glycolysis-related enzymes was promoted significantly, including PK, HK, PKF, LDH, and the related HK gene. In contrast, enzymes linked to aerobic respiration, PDH, and SDH, as well as the related PDH and SDH genes, displayed down-regulation, signifying a transition from aerobic to anaerobic metabolism. Additionally, the activity of gluconeogenesis-related enzymes such as PK and G6Pase gene expression were significantly elevated, indicating the activation of gluconeogenesis and glycogenolysis pathways. Consequently, juvenile T. tridentatus demonstrated an adaptive response to hypoxic conditions, marked by changes in respiratory energy metabolism modes and the activation of hypoxia signaling pathways.

Respiratory Support Effects over Time on Regional Lung Ventilation Assessed by Electrical Impedance Tomography in Premature Infants.

Background and objectives: Respiratory distress syndrome (RDS) frequently necessitates respiratory support. While non-invasive methods are typically the preferred approach, mechanical ventilation becomes necessary for patients with insufficient response. Our study aimed to compare two common respiratory support modes, volume-targeted mechanical ventilation and non-invasive ventilation continuous positive airway pressure (CPAP) and high-flow nasal cannula (HFNC), using electrical impedance tomography. Materials and Methods: Infants with very low birth weight and gestational ages of less than 32 weeks were eligible for inclusion in the study. All enrolled infants were beyond the transitional period (>72 h of age). The infants were divided into two groups: infants receiving invasive respiratory support through an endotracheal tube and infants receiving non-invasive respiratory support. We used electrical impedance tomography to assess end-expiratory lung impedance (EELZ), DeltaZ, heterogeneity, and regional ventilation distribution. Patients were evaluated at 0, 30, and 60 min after assuming the supine position to examine potential time-related effects. Results: Our study initially enrolled 97 infants, and the final analysis included a cohort of 72 infants. Ventilated infants exhibited significantly larger EELZ compared to their non-invasive counterparts (p = 0.026). DeltaZ was also greater in the invasive respiratory support group (p < 0.001). Heterogeneity was higher in the non-invasive group and did not change significantly over time. The non-invasive group demonstrated significantly greater ventilation in the dependent lung areas compared to intubated patients (p = 0.005). Regional distribution in the left lung was lower than in the right lung in both groups; however, this difference was significantly more pronounced in intubated patients (p < 0.001). Conclusions: Our study revealed that volume-targeted mechanical ventilation results in higher EELZ and DeltaZ compared to spontaneously breathing infants receiving non-invasive respiratory support. However, lung heterogeneity was lower during mechanical ventilation. Our study also reaffirmed that spontaneous breathing promotes greater involvement of the dependent lung compared to mechanical ventilation.

Enhanced Bacterial Cuproptosis-Like Death via Reversal of Hypoxia Microenvironment for Biofilm Infection Treatment.

A recently emerging cell death pathway, known as copper-induced cell death, has demonstrated significant potential for treating infections. Existing research suggests that cells utilizing aerobic respiration, as opposed to those reliant on glycolysis, exhibit greater sensitivity to copper-induced death. Herein, a MnO2-loaded copper metal-organic frameworks platform is developed denoted as MCM, to enhance bacterial cuproptosis-like death via the remodeling of bacterial respiratory metabolism. The reversal of hypoxic microenvironments induced a cascade of responses, encompassing the reactivation of suppressed immune responses and the promotion of osteogenesis and angiogenesis. Initially, MCM catalyzed O2 production, alleviating hypoxia within the biofilm and inducing a transition in bacterial respiration mode from glycolysis to aerobic respiration. Subsequently, the sensitized bacteria, characterized by enhanced tricarboxylic acid cycle activity, underwent cuproptosis-like death owing to increased copper concentrations and aggregated intracellular dihydrolipoamide S-acetyltransferase (DLAT). The disruption of hypoxia also stimulated suppressed dendritic cells and macrophages, thereby strengthening their antimicrobial activity through chemotaxis and phagocytosis. Moreover, the nutritional effects of copper elements, coupled with hypoxia alleviation, synergistically facilitated the regeneration of bones and blood vessels. Overall, reshaping the infection microenvironment to enhance cuproptosis-like cell death presents a promising avenue for eradicating biofilms.

Non-invasive versus invasive respiratory support in preterm infants

Respiratory insufficiency is almost ubiquitous in infants born preterm, with its incidence increasing with lower gestational age. A wide range of respiratory support management strategies are available for these infants, separable into non-invasive and invasive forms of respiratory support. Here we review the history and evolution of respiratory care for the preterm infant and then examine evidence that has emerged to support a non-invasive approach to respiratory management where able. Continuous positive airway pressure (CPAP) is the non-invasive respiratory support mode currently with the most evidence for benefit. CPAP can be delivered safely and effectively and can commence in the delivery room. Particularly in early life, time spent on non-invasive respiratory support, avoiding intubation and mechanical ventilation, affords benefit for the preterm infant by virtue of a lessening of lung injury and hence a reduction in incidence of bronchopulmonary dysplasia. In recent years, enthusiasm for application of non-invasive support has been further bolstered by new techniques for administration of exogenous surfactant. Methods of less invasive surfactant delivery, in particular with a thin catheter, have allowed neonatologists to administer surfactant without resort to endotracheal intubation. The benefits of this approach appear to be sustained, even in those infants subsequently requiring mechanical ventilation. This cements the notion that any reduction in exposure to mechanical ventilation leads to alleviation of injury to the vulnerable preterm lung, with a long-lasting effect. Despite the clear advantages of non-invasive respiratory support, there will continue to be a role for intubation and mechanical ventilation in some preterm infants, particularly for those born <25 weeks’ gestation. It is currently unclear what role early non-invasive support has in this special population, with more studies required.

Continuous Positive Airway Pressure versus Nasal Intermittent Positive Pressure Ventilation in Preterm Neonates: What if Mean Airway Pressures Were Equivalent?

Respiratory support for preterm neonates in modern neonatal intensive care units is predominantly with the use of noninvasive interfaces. Continuous positive airway pressure (CPAP) and nasal intermittent positive pressure ventilation (NIPPV) are the prototypical and most commonly utilized forms of noninvasive respiratory support, and each has unique gas flow characteristics. In meta-analyses of clinical trials till date, NIPPV has been shown to likely reduce respiratory failure and need for intubation compared to CPAP. However, a significant limitation of the included studies has been the higher mean airway pressures used during NIPPV. Thus, it is unclear to what extent any benefits seen with NIPPV are due to the cyclic pressure application versus the higher mean airway pressures. In this review, we elaborate on these limitations and summarize the available evidence comparing NIPPV and CPAP at equivalent mean airway pressures. Finally, we call for further studies comparing noninvasive respiratory support modes at equal mean airway pressures. KEY POINTS: · Most current literature on CPAP vs. NIPPV in preterm neonates is confounded by use of higher mean airway pressures during NIPPV.. · In this review, we summarize existing evidence on CPAP vs. NIPPV at equivalent mean airway pressures.. · We call for future research on noninvasive support modes to account for mean airway pressures..

Responses of intraspecific metabolic scaling to temperature and activity differ between water- and air-breathing ectothermic vertebrates.

Metabolism underpins all life-sustaining processes and varies profoundly with body size, temperature and locomotor activity. A current theory explains some of the size-dependence of metabolic rate (its mass exponent, b) through changes in metabolic level (L). We propose two predictive advances that: (a) combine the above theory with the evolved avoidance of oxygen limitation in water-breathers experiencing warming, and (b) quantify the overall magnitude of combined temperatures and degrees of locomotion on metabolic scaling across air- and water-breathers. We use intraspecific metabolic scaling responses to temperature (523 regressions) and activity (281 regressions) in diverse ectothermic vertebrates (fish, reptiles and amphibians) to show that b decreases with temperature-increased L in water-breathers, supporting surface area-related avoidance of oxygen limitation, whereas b increases with activity-increased L in air-breathers, following volume-related influences. This new theoretical integration quantitatively incorporates different influences (warming, locomotion) and respiration modes (aquatic, terrestrial) on animal energetics.

Pandemic storytelling and student engagement: how students imagined pandemics before COVID-19 pandemic.

Student engagement is one of the critical issues in science classes. This commentary explores the value of storytelling in microbiology education and student engagement. It is a result of an undergraduate exercise, where students were asked to draft short stories on pandemics before the COVID-19 pandemic (i.e. conducted in 2016-2019). The analysis of student writings (total of 244 short stories) aimed to understand the students' perception of pandemics, the diseases they chose to write about, and their level of knowledge of pandemics. Interestingly, 56.6% of students chose viruses to be the cause of their pandemics, 35.7% chose bacteria, 4.5% chose parasites, and a single student chose a fungus. Respiratory mode of transmission was the top pick in the stories (30%), followed by fecal-oral route, sexually transmitted, and skin-to-skin contact. Therefore, their choice of respiratory diseases as the focus of their short story may suggest their limited understanding of pandemics beyond such diseases. The varying levels of detail in the stories suggested that storytelling could be insightful in identifying knowledge gaps and engaging students. Two exciting questions remain: (1) For the students who wrote those short stories before the COVID-19 pandemic, how did they feel when it hit? (2) If the students are asked again to write a pandemic short story, what would it look like nowadays? A deeper understanding of epidemiology and the social impact of pandemics is crucial for developing effective pandemic preparedness and response plans, and undergraduate courses can play a vital role in this endeavor. Overall, this commentary highlights the value of storytelling in engaging students to assess their knowledge of specific subject matters.

Influencing factors of prognosis in elderly patients with COPD complicated with respiratory failure and the intervention effect of specialized nursing and respiratory training mode

Influencing factors of prognosis in elderly patients with COPD complicated with respiratory failure and the intervention effect of specialized nursing and respiratory training mode