Impact of under-assisted ventilation on diaphragm function and structure in a porcine model.

Background: Long-term controlled mechanical ventilation (CMV) in intensive care unit (ICU) induces ventilatory-induced-diaphragm-dysfunction (VIDD). The transition from CMV to assisted mechanical ventilation is a challenge that requires clinicians to balance over-assistance and under-assistance. While the effects of over-assistance on the diaphragm are well known, we aimed to assess the impact of under-assistance on diaphragm function and structure in piglet model with pre-existing VIDD (after long-term CMV) or without VIDD (short-term CMV).

Acute selective serotonin-reuptake inhibition elevates basal ventilation, attenuates the rebreathing ventilatory response, independent of cerebral perfusion.

Serotonin (5-HT) is integral to signalling in areas of the brainstem controlling ventilation and is involved in central chemoreception. Selective serotonin reuptake inhibitors (SSRIs), used to effectively increase 5-HT concentrations, are commonly prescribed for depression. The effects of SSRIs on the control of breathing and the potential influence of cerebral blood flow (CBF) have not been directly assessed.

Confined spaces in space: Cerebral implications of chronic elevations of inspired carbon dioxide and implications for long-duration space travel.

Cerebrovascular regulation is critically dependent upon the arterial partial pressure of carbon dioxide ( ), owing to its effect on cerebral blood flow, tissue , tissue proton concentration, cerebral metabolism and cognitive and neuronal function. In normal environments and in the absence of pathology, at least over acute time frames, hypercapnia is usually managed readily via the respiratory chemoreflex arcs and/or acid-base buffering capacity, such that there is minimal impact on cerebrovascular and neurological function. However, in non-normal environments, such as enclosed spaces, or with pathology, extended exposures to elevations in can be detrimental to cerebral health.

Post-transcriptional modifications on tRNA fragments confer functional changes to high-density lipoproteins in atherosclerosis.

Epitranscriptomic modifications on RNA play critical roles in stability, processing, and function, partly by influencing interactions with RNA-binding proteins and receptors. The role of post-transcriptional RNA modifications on cell-free non-coding small RNA (sRNA) remains poorly understood in disease contexts. High-density lipoproteins (HDL), which transport sRNAs, can lose their beneficial properties in atherosclerosis cardiovascular disease (ASCVD).