Carotid body dysregulation contributes to Long COVID symptoms.

Background: The symptoms of long COVID, which include fatigue, breathlessness, dysregulated breathing, and exercise intolerance, have unknown mechanisms. These symptoms are also observed in heart failure and are partially driven by increased sensitivity of the carotid chemoreflex. As the carotid body has an abundance of ACE2 (the cell entry mechanism for SARS-CoV-2), we investigated whether carotid chemoreflex sensitivity was elevated in participants with long COVID.

Aging in females is associated with changes in respiratory modulation of sympathetic nerve activity and blood pressure.

Sympathetic nerve activity (SNA) is tightly coupled with the respiratory cycle. In healthy human males, respiratory modulation of SNA does not change with age. However, it is unclear how this modulation is affected by age in females.

Ventilatory Efficiency Is Reduced in People With Hypertension During Exercise.

Background An elevated ventilatory efficiency slope during exercise (minute ventilation/volume of expired CO; V/VCO slope) is a strong prognostic indicator in heart failure. It is elevated in people with heart failure with preserved ejection, many of whom have hypertension. However, whether the V/VCO slope is also elevated in people with primary hypertension versus normotensive individuals is unknown.

International consensus on lung function testing during the COVID-19 pandemic and beyond.

Coronavirus disease 2019 (COVID-19) has negatively affected the delivery of respiratory diagnostic services across the world due to the potential risk of disease transmission during lung function testing. Community prevalence, reoccurrence of COVID-19 surges and the emergence of different variants of SARS-CoV-2 have impeded attempts to restore services. Finding consensus on how to deliver safe lung function services for both patients attending and for staff performing the tests are of paramount importance.

Sleep-wake disturbances in patients with advanced cancer and their family carers.

Sleep disturbance is common in patients with advanced cancer, and their family carers also may suffer from sleep problems. The aims of this study were to determine the prevalence of sleep-wake disturbances in patients with advanced cancer and their carers, to monitor the amount of daytime spent in activity and rest, and to examine the relationship between sleep, physical, and psychological symptoms. This was a prospective, descriptive observational study in patients with advanced incurable cancer and their carers attending a regional cancer center, using subjective (Short Form-36, Epworth Sleepiness Score, Hospital Anxiety and Depression Scale, Memorial Symptom Assessment Scale, and sleep history and diary) and objective (Actiwatch) assessments over a seven-day period.

Behavioral and cardiovascular effects of 7.5% CO2 in human volunteers.

The study of carbon dioxide (CO2) inhalation in psychiatry has a long and varied history, with recent interest in using inhaled CO2 as an experimental tool to explore the neurobiology and treatment of panic disorder. As a consequence, many studies have examined the panic-like response to the gas either using the single or double breath 35% CO2 inhalation or 5-7% CO2 inhaled for 15-20 min, or rebreathing 5% CO2 for a shorter time. However, this lower dose regime produces little physiological or psychological effects in normal volunteers.

Inhalation of 35% CO(2) results in activation of the HPA axis in healthy volunteers.

Background: The hypothalamo-pituitary-adrenal (HPA) axis is a major stress responsive system in humans. Although there are numerous ways of testing responsiveness of the HPA in experimental animals, this is much more difficult in man. Hypercapnea is a very stressful stimulus for humans and has been used as an anxiogenic probe in psychiatric patients.