Paradoxical effects of mild hypoxia and moderate altitude on human visual perception

1992 ◽  
Vol 83 (5) ◽  
pp. 633-636 ◽  
Author(s):  
Thomas E. Schlaepfer ◽  
Peter Bärtsch ◽  
Hans U. Fisch
Keyword(s):  
Cognitive Performance ◽  
Chronic Obstructive ◽  
Moderate Altitude ◽  
Human Visual Perception ◽  
Obstructive Pulmonary Disease ◽  
Hypoxic Conditions ◽  
Paradoxical Effects ◽  
Common Notion ◽  
The Common ◽  
Mild Hypoxia

1. Prolonged (> 10h) exposure to hypoxia and high altitude (> 5000 m) invariably have detrimental effects on cognitive performance. Paradoxically, mild improvements in cognitive function in patients with chronic obstructive pulmonary disease after cessation of oxygen therapy have been reported. 2. We studied in each of 10 healthy subjects the effect of an acute altitude challenge [rapid helicopter transport to the Jungfraujoch (3450 m), experiment 1] and of an acute exposure to mild hypoxia (fractional inspiratory oxygen concentration 14.5%, experiment 2) on a simple test of cognitive performance (the time needed to read briefly displayed letters). 3. Under both hypoxic conditions the time needed to read briefly presented letters decreased, from 12.1 ± sd 3.8 ms to 8.3 ± 1.5 ms (P<0.01) in experiment 1, and from 11.9 ± 1.9 ms to 8.1 ± 1.1 ms (P<0.01) in experiment 2. 4. A rapid and mild hypoxic challenge seems to improve a simple measure of cognitive performance above normal values. The common notion that exposure to hypoxia and altitude invariably impairs cognitive performance may have to be re-evaluated.

scholarly journals COVID-19 Shuts Doors to Flu but Keeps Them Open to Rhinoviruses

Biology ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 733
Author(s):  
Irina Kiseleva ◽  
Andrey Ksenafontov
Keyword(s):  
Influenza Pandemic ◽  
Age Groups ◽  
Influenza Viruses ◽  
Interferon Response ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Mild Disease ◽  
Viral Interference ◽  
The Common

It is well known that rhinoviruses are distributed across the globe and are the most common cause of the common cold in all age groups. Rhinoviruses are widely considered to be harmless because they are generally perceived as respiratory viruses only capable of causing mild disease. However, they may also infect the lower respiratory tract, inducing chronic obstructive pulmonary disease and exacerbations of asthma, bronchiolitis, etc. The role of rhinoviruses in pathogenesis and the epidemiological process is underestimated, and they need to be intensively studied. In the light of recent data, it is now known that rhinoviruses could be one of the key epidemiological barriers that may influence the spread of influenza and novel coronaviruses. It has been reported that endemic human rhinoviruses delayed the development of the H1N1pdm09 influenza pandemic through viral interference. Moreover, human rhinoviruses have been suggested to block SARS-CoV-2 replication in the airways by triggering an interferon response. In this review, we summarized the main biological characteristics of genetically distinct viruses such as rhinoviruses, influenza viruses, and SARS-CoV-2 in an attempt to illuminate their main discrepancies and similarities. We hope that this comparative analysis will help us to better understand in which direction research in this area should move.

scholarly journals Possible Implication of Hypoxia-mediated Incomplete Neutrophil Extracellular Trap Formation in Pneumonia-induced Exacerbation of Lung Diseases

2021 ◽  
Author(s):  
Sakiko Masuda ◽  
Kurumi Kato ◽  
Misato Ishibashi ◽  
Yuka Nishibata ◽  
Ayako Sugimoto ◽  
...  
Keyword(s):  
Lung Diseases ◽  
Actin Polymerization ◽  
Hypoxia Inducible Factor ◽  
Neutrophil Extracellular Trap ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Hypoxic Conditions ◽  
Pulmonary Arterial ◽  
Underlying Diseases

Abstract When patients with preexisting lung diseases, such as chronic obstructive pulmonary disease, interstitial pneumonitis, and pulmonary arterial hypertension, develop pneumonia, the complication often exacerbates the underlying diseases. Although neutrophil extracellular traps (NETs) are important components of innate immune system, the residue of NETs in the tissue can harm the host. We examined the expression of hypoxia-inducible factor 1α (HIF-1α) and NETs in the lungs of patients with lung diseases complicated with pneumonia, and investigated the properties of NETs generated under hypoxia. This study demonstrated that the amount of NETs in pulmonary lesions was greater in patients with pneumonia than in patients without pneumonia and displayed a positive correlation between the amount of NETs and HIF-1α expression. We further demonstrated that the formation of typical lytic NETs was suppressed and round-shaped NETs were generated under hypoxic conditions in vitro. These round NETs were resistant to digestion by the principal NET regulator, DNase I. Focusing on actin rearrangement in neutrophils stimulated under hypoxic conditions, we found that G-actin polymerization and F-actin degradation—both of which are observed time-dependently under normoxic conditions—were disrupted, suggesting that hypoxia mediated the incomplete NET formation. Moreover, neutrophils stimulated under hypoxic conditions possessed cytotoxicity. Accumulation of neutrophils that form degradation-resistant NETs and possess cytotoxicity, which are generated under hypoxic circumstances, are expected to be involved in exacerbation of underlying lung diseases complicated with pneumonia.

scholarly journals Association of Rhinovirus Infections with Asthma

1999 ◽  
Vol 12 (1) ◽  
pp. 9-18 ◽  
Author(s):  
James E. Gern ◽  
William W. Busse
Keyword(s):  
Allergic Inflammation ◽  
Epidemiologic Studies ◽  
Detection Methods ◽  
Chronic Obstructive ◽  
Tissue Destruction ◽  
Obstructive Pulmonary Disease ◽  
Antiviral Responses ◽  
Asthma Exacerbations ◽  
Rhinovirus Infection ◽  
The Common

SUMMARY Rhinoviruses are the most common cause of the common cold, but they can cause more severe illnesses in people with underlying lung disorders such as asthma, chronic obstructive pulmonary disease, or cystic fibrosis. Epidemiologic studies with sensitive detection methods such as PCR have identified rhinovirus infection as a major source of asthma exacerbations in both children and adults, especially during the spring and fall. Since rhinoviruses cause little tissue destruction, it is presumed that the immune response to the infection may play an important role in the pathogenesis of rhinovirus-induced exacerbations of asthma. This review examines the epidemiologic association between rhinovirus infections and exacerbations of asthma and outlines current information on immune responses to rhinovirus infection and potential connections between antiviral responses and preexisting allergic inflammation. Finally, current and future strategies for treating rhinovirus infections and virus-induced exacerbations of asthma are discussed.

Clinical Profile of Critically Ill Patients Presenting to Emergency Department of Tertiary Level Hospital of Nepal

2019 ◽  
Vol 41 (1) ◽  
pp. 67-74
Author(s):  
Shubha K Shrestha ◽  
Bishwas Pradhan ◽  
Yogendra M Shakya ◽  
Hem R Paneru
Keyword(s):  
Critically Ill ◽  
Critically Ill Patients ◽  
University Teaching ◽  
Chronic Obstructive ◽  
Optimal Care ◽  
Obstructive Pulmonary Disease ◽  
Number Of Patients ◽  
Common Diagnosis ◽  
The Common ◽  
A Prospective Study

Introduction: Among critically ill patients presenting to Emergency Room (ER) of Tribhuwan University Teaching Hospital (TUTH), a number of patients have to either remain in ER or have to be referred outside due to unavailability of critical care beds. Studies have shown significant association between delayed admission and mortality rates along with increased length of stay and higher cost. This study aimed to present an audit of critically ill patients presenting to ER of TUTH. Methods: This was a prospective study conducted over a period of one month. All patients presenting to ER of TUTH were triaged and critically ill patients were shifted to Red area of the ER. All patients ≥16 years of age shifted to Red area during the study period were enrolled in our study. Results: Out of 3718 patients presenting to ER during the study period, the number of critically ill patients ≥16 years of age was 526 i.e. 14.14% of total patients. Among them, the common diagnosis were Cerebrovascular Accidents (CVA) followed by Intoxication, Acute Exacerbation (AE) of Chronic Obstructive Pulmonary Disease (COPD), Pneumonia and Chronic Kidney Disease (CKD) respectively. Almost 20% of these patients were admitted, 31% were referred and 40% were shifted for observation. The median length of ER stay was 6 hours (Mean: 8.5 hrs; Range: 20 min to 70 hr 15 min). Conclusion: Among critically ill patients presenting to our ER, almost 1/5th of the patients were admitted whereas more than 2/3rd were either referred or remained in our ER. This data highlights the need for solutions to provide optimal care for the acute phase management of the critically ill patients.

scholarly journals Impact of the COVID-19 pandemic on the behaviour and health status of patients with chronic obstructive pulmonary disease – results from the German COPD cohort COSYCONET

2021 ◽  
pp. 00242-2021
Author(s):  
Kathrin Kahnert ◽  
Johanna I. Lutter ◽  
Tobias Welte ◽  
Peter Alter ◽  
Jürgen Behr ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Control Measures ◽  
Clinical State ◽  
Chronic Obstructive ◽  
Protective Measures ◽  
Obstructive Pulmonary Disease ◽  
Infection Control Measures ◽  
Public Media ◽  
Common Notion

BackgroundInfection control measures for COVID-19 might have affected management and clinical state of patients with chronic obstructive pulmonary disease (COPD). We analysed to which extent this common notion is fact-based.MethodsPatients of the COSYCONET cohort were contacted with three recurring surveys (COVID1, 2, 3 at 0, 3 and 6 months). The questionnaires comprised behaviour, clinical and functional state and medical treatment. The responses to the questionnaires were compared amongst themselves and with pre-COVID information from the last visit of COSYCONET.ResultsOverall, 594 patients were contacted and 375 patients (58% males, FEV1 61±22%predicted) provided valid data in COVID1 and COVID2. Five patients reported infections with SARS-CoV-2. Most patients – except for patients with higher education – reported compliance with recommended protective measures, whereby compliance to hygiene, contact and access to physicians slightly improved between COVID1 and COVID2. Also, patients obtained more information from physicians than from public media. In the majority of cases, the personal physician could not be substituted by remote consultation. Over time, symptoms slightly increased and self-assessed physical capacity decreased. Results of COVID3 were similar. Women and patients with more exacerbations and dyspnoea avoided medical consultations, whereas GOLD D patients were more amenable to tele-consultation.ConclusionIn well-characterised COPD patients, we observed on average slight deteriorations of clinical state during the period of COVID-19 restrictions, with high and partially increasing adherence to protective measures. The data suggest that in particular women and GOLD D patients should be actively contacted by physicians to identify deteriorations.

scholarly journals Clinical and Functional Characteristics of Subjects with Asthma, COPD, and Asthma-COPD Overlap: A Multicentre Study in Vietnam

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Sy Duong-Quy ◽  
Huong Tran Van ◽  
Anh Vo Thi Kim ◽  
Quyen Pham Huy ◽  
Timothy J. Craig
Keyword(s):  
Combined Treatment ◽  
Airflow Limitation ◽  
Chronic Obstructive ◽  
Inclusion Criteria ◽  
Functional Characteristics ◽  
Obstructive Pulmonary Disease ◽  
Copd Patients ◽  
Significant Probability ◽  
Functional Features ◽  
The Common

Introduction. Subjects with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) share common features of patients with asthma and COPD. Our study was planned to describe the clinical and functional features of subjects with ACO compared to asthma and COPD patients.Subjects and Methods. Study subjects who met the inclusion criteria were classified into three different groups: asthma, COPD, and ACO groups. All study subjects underwent clinical examination and biological and functional testing. They were then followed for 6 months to evaluate the response to conventional treatment.Results. From March 2015 to March 2017, 76 asthmatic (mean age: 41 ± 22 years), 74 COPD (59 ± 13 years), and 59 ACO (52 ± 14 years) subjects were included. The percentage of subjects with dyspnea on excretion in the ACO group was higher than that in asthma and COPD groups (P<0.001andP<0.05, resp.). Subjects with COPD and ACO had significant airflow limitation (FEV1) compared to asthma (64 ± 17% and 54 ± 14% versus 80 ± 22%;P<0.01andP<0.01, resp.). The levels of FENO in subjects with asthma and ACO were significantly higher than those in subjects with COPD (46 ± 28 ppb and 34 ± 12 ppb versus 15 ± 8 ppb;P<0.001andP<0.001, resp.). VO2max and 6MWD were improved in study subjects after 6 months of treatment. Increased CANO and AHI > 15/hour had a significant probability of risk for ACO (OR = 33.2,P<0.001, and OR = 3.4,P<0.05, resp.).Conclusion. Subjects with ACO share the common clinical and functional characteristics of asthma and COPD but are more likely to have sleep apnea. The majority of patients with ACO have a favourable response to combined treatment.

A randomised-placebo controlled study into the efficacy of working memory training in chronic obstructive pulmonary disease: the study protocol

2019 ◽  
Author(s):  
Sarah Mount ◽  
Katrijn Houben ◽  
Harry Gosker ◽  
Martijn van Beers ◽  
Lisanne Schuurman ◽  
...  
Keyword(s):  
Physical Activity ◽  
Chronic Obstructive Pulmonary Disease ◽  
Working Memory ◽  
Dietary Intake ◽  
Cognitive Performance ◽  
Health Behaviours ◽  
Self Control ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Stress Susceptibility

Abstract Background General cognitive impairment is highly prevalent in patients with chronic obstructive pulmonary disease (COPD). Domain-specific cognitive impairments include deficits in working memory (WM), cognitive flexibility, verbal memory, planning and psychomotor speed. These impairments may be associated with poor health behaviours, such as a sedentary lifestyle and low-quality diet. Cognitive training may reverse these effects. Recent evidence suggests that WM training is linked to self-control and, indirectly, to improved lifestyle behaviour including increased physical activity. We aim to investigate the efficacy of WM training (WMT) in patients with COPD on cognitive performance, cognitive stress susceptibility and perception, self-control, and adherence to personalised physical activity and dietary behaviour goals. Methods A double blind, placebo-controlled randomised trial will be conducted in 60 patients with COPD. The trial will consist of two phases; 12 weeks of active WM training or sham training followed by 12 weeks of maintenance. Prior to the WMT, before the first phase, participants in both the sham (n=30) and training group (n=30) will set dietary and physical activity goals based on their dietary intake and physical activity profile using validated tools. Cognitive performance will be examined using the Cambridge Neuropsychological Test Automated Battery. The primary outcome of this study will be change in cognitive performance. Secondary outcomes will be self-control (impulsivity), compliance, stress susceptibility and perception, change in dietary intake and daily physical activity level and pattern. Discussion This trial will attempt to determine if cognitive performance can be improved in patients with COPD by WMT. Moreover, WM plays a key role in self-regulation of behaviour, i.e. resisting hedonic impulses in exchange for more deliberate evaluations and the achievement of long-term goals. Therefore, we expect that WMT will also have a positive impact on health behaviours. Registration Clinicaltrials.gov registration: NCT03073954

scholarly journals Pulmonary neuroendocrine cells: physiology, tissue homeostasis and disease

2020 ◽  
Vol 13 (12) ◽  
pp. dmm046920
Author(s):  
Masafumi Noguchi ◽  
Kana T. Furukawa ◽  
Mitsuru Morimoto
Keyword(s):  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Lung Ventilation ◽  
Neuroendocrine Cells ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Congenital Diseases ◽  
Hypoxic Conditions ◽  
Pulmonary Neuroendocrine Cells ◽  
Large Clusters

ABSTRACTMammalian lungs have the ability to recognize external environments by sensing different compounds in inhaled air. Pulmonary neuroendocrine cells (PNECs) are rare, multi-functional epithelial cells currently garnering attention as intrapulmonary sensors; PNECs can detect hypoxic conditions through chemoreception. Because PNEC overactivation has been reported in patients suffering from respiratory diseases – such as asthma, chronic obstructive pulmonary disease, bronchopulmonary dysplasia and other congenital diseases – an improved understanding of the fundamental characteristics of PNECs is becoming crucial in pulmonary biology and pathology. During the past decade, murine genetics and disease models revealed the involvement of PNECs in lung ventilation dynamics, mechanosensing and the type 2 immune responses. Single-cell RNA sequencing further unveiled heterogeneous gene expression profiles in the PNEC population and revealed that a small number of PNECs undergo reprogramming during regeneration. Aberrant large clusters of PNECs have been observed in neuroendocrine tumors, including small-cell lung cancer (SCLC). Modern innovation of imaging analyses has enabled the discovery of dynamic migratory behaviors of PNECs during airway development, perhaps relating to SCLC malignancy. This Review summarizes the findings from research on PNECs, along with novel knowledge about their function. In addition, it thoroughly addresses the relevant questions concerning the molecular pathology of pulmonary diseases and related therapeutic approaches.

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