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Altitude, temperature, circadian rhythms and exercise
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Henning Wackerhage, Kenneth A. Dyar, Martin Schönfelder
Humans can adapt to the lower PO2 at high altitude through several mechanisms: We hyperventilate at higher altitudes, which is a systemic response when blood oxygenation (PaO2) drops.Hypoxia-signal transduction is a cell-specific response to hypoxia that triggers adaptation such as an erythropoietin-mediated stimulation of erythrocyte production (polycythemia) and other adaptations that allow cells and the body to compensate and adapt to the lower oxygen levels.Genetic inheritance in humans living at higher altitudes (e.g. people living on the Tibetan plateau, the Andean altiplano and in the East African highlands) because of natural selection of specific genotypes.
Pulmonary Oedema, Lymphangitis Carcinomatosa and ARDS.
Published in Fred W Wright, Radiology of the Chest and Related Conditions, 2022
Pleural effusions are relatively uncommon, and the heart is often of normal size. Some patients recover completely, whilst others develop diffuse fibrosis (sometimes within one to two weeks), and when this occurs only slowly recover after several weeks or months. About half of the cases are fatal, particularly if secondary infection, diffuse intra-vascular coagulation, coma or multisystem failure occur. Assisted ventilation is often used to maintain blood oxygenation, as well as general supportive therapy. The assisted ventilation may lead to bullous formation and pneumothoraces, the latter often being difficult to recognise on radiographs taken in supine or semi-recumbent positions (see ps. 14.22 - 23); 'shoot-through' lateral views and/or CT may be required to show them (see above).
Clinical Workflows Supported by Patient Care Device Data
Published in John R. Zaleski, Clinical Surveillance, 2020
Oxygen is administered initially through the mechanical ventilator at a level exceeding that of room air (i.e., 21%). This is usually referred to as the fraction of inspired oxygen (FiO2), and is then reduced to room air once the patient’s blood oxygenation level is determined and verified as being within a normal range. By the time of endotracheal tube extubation inspired oxygen fraction is normally around 21% (room air).
Altered brain activity and functional connectivity in migraine without aura during and outside attack
Published in Neurological Research, 2023
Luping Zhang, Wenjing Yu, Zhengxiang Zhang, Maosheng Xu, Feng Cui, Wenwen Song, Zhijian Cao
Functional magnetic resonance imaging (fMRI) is the most commonly used method for assessing brain activity. It indirectly measures neural activity by measuring the local changes in blood oxygenation. The amplitude low-frequency fluctuations (ALFF) derived from the resting-state fMRI signals can reflect the regional spontaneous neural activity [8,9]. Functional connectivity (FC) is a method to characterize the temporal neurophysiological activities interactions between brain regions that are spatially remote [10]. Thus, in this study, we used the resting-state functional magnetic resonance imaging (rs-fMRI) method to detect cortical excitability changes and abnormal FC in MWoA-DA and MWoA-DI groups to explore the pathophysiological mechanism of migraine. Additionally, we assessed the relationships between neuroimaging findings and clinical parameters to further explore the relationship between these parameters and the role of these changes in the migraine pathophysiology.
Mobile phone induced EMF stress is reversed upon the use of protective devices: results from two experiments testing different boundary conditions
Published in Electromagnetic Biology and Medicine, 2022
Another area of stress-induced effects of EMF can be found in hematological studies. For instance, erythrocytes have been found to form rouleaux under electromagnetic fields, resulting in a decrease in red blood cell counts (Kozma et al. 2011; Mousavy et al. 2009; Sebastián et al. 2005; Vagdatli et al. 2014). Animals exposed to 30-min mobile phone devices display color alterations in erythrocytes indicating lack of hemoglobin (Alghamdi and El-Ghazaly 2012). These authors suggested that a hypoxia-like status probably results from the oxygen-binding impairment of hemoglobin and the overproduction of reactive oxygen species caused by EMF. The effects of free radicals on the erythrocyte membrane may also contribute to the leak of hemoglobin out of the cells (Jbireal et al. 2018). Blood oxygenation is kept within relatively narrow margins to secure tissue oxygenation (McClatchey 2017), but impairment of hemoglobin binding may potentially result in a measurable decrease of arterial blood oxygenation. Whether short-term exposure to EMF emitted by mobile phones causes such effects, however, has not been systematically established.
Neural Activity Across the Dorsolateral Prefrontal Cortex and Risk for Suicidal Ideation and Self-Injury
Published in Archives of Suicide Research, 2022
Zarmeen Zahid, Liam McMahon, Michael Lynch
Based on the existing literature, it appears that dlPFC activity is implicated in cognitive and emotional processes associated with coping and regulation, two processes extensively linked to NSSI and suicidal ideation. As a result, dlPFC activity may play a role in the likelihood of suicidal ideation and NSSI. By linking the two constructs to coping and emotional dysregulation, the current study sought to build on these associations by examining more directly the relationship between underlying dlPFC activity and both suicidal ideation and NSSI. The goal of the current study was to examine the possible association between patterns of activity in the dlPFC and self-reports of suicidal ideation and NSSI among a sample of college students. Specifically, activity across the dlPFC was monitored during cognitively challenging anagram tasks using functional near-infrared spectroscopy (fNIRS). This measurement technique makes estimates of neural activity by quantifying changes in blood oxygenation as determined by the amount of infrared light that is absorbed or reflected at multiple locations across the region of interest. Anagram tasks were chosen because they require sustained engagement across several cognitive domains in order to perform well while presenting various levels of difficulty in a manner consistent with everyday cognitive demands. It was hypothesized that reports of suicidal ideation and NSSI would be associated with patterns of activity across the dlPFC that were distinct from those observed in people who did not report suicidal ideation or NSSI.