Pulmonary function tests in the neonatal intensive care unit and beyond: a clinical review
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Severity of neonatal influenza infection is driven by type I interferon and oxidative stress
Neonates exhibit increased susceptibility to respiratory viral infections, attributed to inflammation at the developing pulmonary air-blood interface. IFN I are antiviral cytokines critical to control viral replication, but also promote inflammation. Previously, we established a neonatal murine influenza virus (IV) model, which demonstrates increased mortality. Here, we sought to determine the role of IFN I in this increased mortality. We found that three-day-old IFNAR-deficient mice are highly protected from IV-induced mortality. In addition, exposure to IFNβ 24 h post IV infection accelerated death in WT neonatal animals but did not impact adult mortality. In contrast, IFN IIIs are protective to neonatal mice. IFNβ induced an oxidative stress imbalance specifically in primary neonatal IV-infected pulmonary type II epithelial cells (TIIEC), not in adult TIIECs. Moreover, neonates did not have an infection-induced increase in antioxidants, including a key antioxidant, superoxide dismutase 3, as compared to adults. Importantly, antioxidant treatment rescued IV-infected neonatal mice, but had no impact on adult morbidity. We propose that IFN I exacerbate an oxidative stress imbalance in the neonate because of IFN I-induced pulmonary TIIEC ROS production coupled with developmentally regulated, defective antioxidant production in response to IV infection. This age-specific imbalance contributes to mortality after respiratory infections in this vulnerable population.
PGRMC2 is a pressure-volume regulator critical for myocardial responses to stress in mice
Progesterone receptors are classified into nuclear and membrane-bound receptor families. Previous unbiased proteomic studies indicate a potential association between cardiac diseases and the progesterone receptor membrane-bound component-2 (PGRMC2); however, the role of PGRMC2 in the heart remains unknown. In this study, we use a heart-specific knockout (KO) mouse model (MyH6•Pgrmc2flox/flox) in which the Pgrmc2 gene was selectively deleted in cardiomyocytes. Here we show that PGRMC2 serves as a mediator of steroid hormones for rapid calcium signaling in cardiomyocytes to maintain cardiac contraction, sufficient stroke volume, and adequate cardiac output by regulating the cardiac pressure-volume relationship. The KO hearts from male and female mice exhibit an impairment in pressure-volume relationship. Under hypoxic conditions, this pressure-volume dysregulation progresses to congestive left and right ventricular failure in the KO hearts. Overall, we propose that PGRMC2 is a cardiac pressure-volume regulator to maintain normal cardiac physiology, especially during hypoxic stress.
Currency harmonisation in the Southern African Development Community: a pathway to addressing the PPP puzzle
Over a century since its inception, the purchasing power parity (PPP) theory, linking exchange rates to relative prices, remains one of the most widely accepted and influential theories in international economics. Despite its theoretical appeal, the empirical validity of PPP remains highly contentious. This study examines the empirical support for PPP within the Southern African Development Community (SADC) region. We employ a battery of linear and ESTAR nonlinear unit root tests, panel stationarity tests, and multivariate cointegration analysis on two distinct numéraire currencies—US dollar and the South African rand (ZAR)—alongside consumer price index (CPI) data for 14 SADC countries over the monthly period 1990:01–2022:04. To this end, we test two important hypotheses in the literature on whether the empirical validity of PPP is influenced by the: (i) ‘numéraire currency’ effect, and (ii) ‘border’ effect. Overall, our findings lend overwhelming support to both of these conjectures. Further evidence suggests that the half-life of parity reversion is significantly shorter for the ZAR-based real exchange rates. These findings imply that SADC meets the optimum currency area (OCA) requirements, making the proposed monetary union a promising prospect.
Iron homeostasis and ferroptosis in muscle diseases and disorders: mechanisms and therapeutic prospects
The muscular system plays a critical role in the human body by governing skeletal movement, cardiovascular function, and the activities of digestive organs. Additionally, muscle tissues serve an endocrine function by secreting myogenic cytokines, thereby regulating metabolism throughout the entire body. Maintaining muscle function requires iron homeostasis. Recent studies suggest that disruptions in iron metabolism and ferroptosis, a form of iron-dependent cell death, are essential contributors to the progression of a wide range of muscle diseases and disorders, including sarcopenia, cardiomyopathy, and amyotrophic lateral sclerosis. Thus, a comprehensive overview of the mechanisms regulating iron metabolism and ferroptosis in these conditions is crucial for identifying potential therapeutic targets and developing new strategies for disease treatment and/or prevention. This review aims to summarize recent advances in understanding the molecular mechanisms underlying ferroptosis in the context of muscle injury, as well as associated muscle diseases and disorders. Moreover, we discuss potential targets within the ferroptosis pathway and possible strategies for managing muscle disorders. Finally, we shed new light on current limitations and future prospects for therapeutic interventions targeting ferroptosis.
Exploring dietitians’ experiences caring for patients living with obesity in acute care: a qualitative study
Obesity is a modifiable risk factor associated with hospital-associated complications. Recent studies show there is a high prevalence of patients with obesity presenting to hospital and evidence indicates that people living with obesity should receive diet advice from a dietitian; however, patients often do not receive this care in acute settings.
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