Denis Jourdanet (1815–1892) and the early recognition of the role of hypoxia at high altitude

2013 ◽  
Vol 305 (5) ◽  
pp. L333-L340 ◽  
Author(s):  
John B. West ◽  
Jean-Paul Richalet
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Early Recognition ◽  
Critical Role ◽  
Barometric Pressure ◽  
Low Oxygen ◽  
Rapid Pulse ◽  
The One ◽  
Clear Statement

Denis Jourdanet (1815–1892) was a French physician who spent many years in Mexico studying the effects of high altitude. He was a major benefactor of Paul Bert (1833–1886), who is often called the father of high-altitude physiology because his book La pression barométrique was the first clear statement that the harmful effects of high altitude are caused by the low partial pressure of oxygen. However, Bert's writings make it clear that the first recognition of the critical role of hypoxia at high altitude should be credited to Jourdanet. Jourdanet noted that some of his patients at high altitude had features that are typical of anemia at sea level, including rapid pulse, dizziness, and occasional fainting spells. These symptoms were correctly attributed to the low oxygen level in the blood and he coined the terms “anoxyhémie” and “anémie barométrique” to draw a parallel between the effects of high altitude on the one hand and anemia at sea level on the other. He also studied the relations between barometric pressure and altitude, and the characteristics of the native populations in Mexico at different altitudes. Jourdanet believed that patients with various diseases including pulmonary tuberculosis were improved if they went to altitudes above 2,000 m. This led him to recommend “aérothérapie” in which these patients were treated in low-pressure chambers. Little has been written about Jourdanet, and his work deserves to be better known.

Improvement in lung diffusion by endothelin A receptor blockade at high altitude

2012 ◽  
Vol 112 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Claire de Bisschop ◽  
Jean-Benoit Martinot ◽  
Gil Leurquin-Sterk ◽  
Vitalie Faoro ◽  
Hervé Guénard ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Exercise Capacity ◽  
Barometric Pressure ◽  
Membrane Component ◽  
Alveolar Volume ◽  
Double Blind ◽  
Lung Diffusion ◽  
Endothelin A Receptor ◽  
Endothelin A

Lung diffusing capacity has been reported variably in high-altitude newcomers and may be in relation to different pulmonary vascular resistance (PVR). Twenty-two healthy volunteers were investigated at sea level and at 5,050 m before and after random double-blind intake of the endothelin A receptor blocker sitaxsentan (100 mg/day) vs. a placebo during 1 wk. PVR was estimated by Doppler echocardiography, and exercise capacity by maximal oxygen uptake (V̇o2 max). The diffusing capacities for nitric oxide (DLNO) and carbon monoxide (DLCO) were measured using a single-breath method before and 30 min after maximal exercise. The membrane component of DLCO (Dm) and capillary volume (Vc) was calculated with corrections for hemoglobin, alveolar volume, and barometric pressure. Altitude exposure was associated with unchanged DLCO, DLNO, and Dm but a slight decrease in Vc. Exercise at altitude decreased DLNO and Dm. Sitaxsentan intake improved V̇o2 max together with an increase in resting and postexercise DLNO and Dm. Sitaxsentan-induced decrease in PVR was inversely correlated to DLNO. Both DLCO and DLNO were correlated to V̇o2 max at sea level ( r = 0.41–0.42, P < 0.1) and more so at altitude ( r = 0.56–0.59, P < 0.05). Pharmacological pulmonary vasodilation improves the membrane component of lung diffusion in high-altitude newcomers, which may contribute to exercise capacity.

Physiology in Medicine: A physiologic approach to prevention and treatment of acute high-altitude illnesses

2015 ◽  
Vol 118 (5) ◽  
pp. 509-519 ◽  
Author(s):  
Andrew M. Luks
Keyword(s):  
High Altitude ◽  
Acute Hypoxia ◽  
Acute Mountain Sickness ◽  
Travel Medicine ◽  
Barometric Pressure ◽  
Time Frame ◽  
Low Oxygen ◽  
Organ Systems ◽  
Prevention And Treatment ◽  
Physiologic Responses

With the growing interest in adventure travel and the increasing ease and affordability of air, rail, and road-based transportation, increasing numbers of individuals are traveling to high altitude. The decline in barometric pressure and ambient oxygen tensions in this environment trigger a series of physiologic responses across organ systems and over a varying time frame that help the individual acclimatize to the low oxygen conditions but occasionally lead to maladaptive responses and one or several forms of acute altitude illness. The goal of this Physiology in Medicine article is to provide information that providers can use when counseling patients who present to primary care or travel medicine clinics seeking advice about how to prevent these problems. After discussing the primary physiologic responses to acute hypoxia from the organ to the molecular level in normal individuals, the review describes the main forms of acute altitude illness—acute mountain sickness, high-altitude cerebral edema, and high-altitude pulmonary edema—and the basic approaches to their prevention and treatment of these problems, with an emphasis throughout on the physiologic basis for the development of these illnesses and their management.

scholarly journals Role of Somatostatin in the Regulation of Central and Peripheral Factors of Satiety and Obesity

2020 ◽  
Vol 21 (7) ◽  
pp. 2568
Author(s):  
Ujendra Kumar ◽  
Sneha Singh
Keyword(s):  
Food Intake ◽  
Hormonal Regulation ◽  
Critical Role ◽  
Eating Behaviour ◽  
Peripheral Tissues ◽  
Complex Process ◽  
The Many ◽  
The One ◽  
Food Seeking

Obesity is one of the major social and health problems globally and often associated with various other pathological conditions. In addition to unregulated eating behaviour, circulating peptide-mediated hormonal secretion and signaling pathways play a critical role in food intake induced obesity. Amongst the many peptides involved in the regulation of food-seeking behaviour, somatostatin (SST) is the one which plays a determinant role in the complex process of appetite. SST is involved in the regulation of release and secretion of other peptides, neuronal integrity, and hormonal regulation. Based on past and recent studies, SST might serve as a bridge between central and peripheral tissues with a significant impact on obesity-associated with food intake behaviour and energy expenditure. Here, we present a comprehensive review describing the role of SST in the modulation of multiple central and peripheral signaling molecules. In addition, we highlight recent progress and contribution of SST and its receptors in food-seeking behaviour, obesity (orexigenic), and satiety (anorexigenic) associated pathways and mechanism.

Effect of beta-adrenoceptor blockade on renin-aldosterone and alpha-ANF during exercise at altitude

1989 ◽  
Vol 67 (1) ◽  
pp. 141-146 ◽  
Author(s):  
P. Bouissou ◽  
J. P. Richalet ◽  
F. X. Galen ◽  
M. Lartigue ◽  
P. Larmignat ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Acute Mountain Sickness ◽  
Plasma Renin ◽  
Barometric Pressure ◽  
Suppressive Effect ◽  
Beta Blockade ◽  
Plasma Norepinephrine ◽  
Plasma Aldosterone Concentration ◽  
Ergometer Exercise

The renin-aldosterone system may be depressed in subjects exercising at high altitude, thereby preventing excessive angiotensin I (ANG I) and aldosterone levels, which could favor the onset of acute mountain sickness. The role of beta-adrenoceptors in hormonal responses to hypoxia was investigated in 12 subjects treated with a nonselective beta-blocker, pindolol. The subjects performed a standardized maximal bicycle ergometer exercise with (P) and without (C) acute pindolol treatment (15 mg/day) at sea level, as well as during a 5-day period at high altitude (4,350 m, barometric pressure 450 mmHg). During sea-level exercise, pindolol caused a reduction in plasma renin activity (PRA, 2.83 +/- 0.35 vs. 5.13 +/- 0.7 ng ANG I.ml-1.h-1, P less than 0.01), an increase in plasma alpha-atrial natriuretic factor (alpha-ANF) level (23.1 +/- 2.9 (P) vs. 10.4 +/- 1.5 (C) pmol/1, P less than 0.01), and no change in plasma aldosterone concentration [0.50 +/- 0.04 (P) vs. 0.53 +/- 0.03 (C) nmol/1]. Compared with sea-level values, PRA (3.45 +/- 0.7 ng ANG I.ml-1.h-1) and PA (0.39 +/- 0.03 nmol/1) were significantly lower (P less than 0.05) during exercise at high altitude. alpha-ANF was not affected by hypoxia. When beta-blockade was achieved at high altitude, exercise-induced elevation in PRA was completely abolished, but no additional decline in PA occurred. Plasma norepinephrine and epinephrine concentrations tended to be lower during maximal exercise at altitude; however, these differences were not statistically significant. Our results provide further evidence that hypoxia has a suppressive effect on the renin-aldosterone system. However, beta-adrenergic mechanisms do not appear to be responsible for inhibition of renin secretion at high altitude.

scholarly journals The role of workplace social capital, compassion satisfaction and secondary traumatic stress in affective organisational commitment of a sample of Iranian nurses

2018 ◽  
Vol 23 (5) ◽  
pp. 446-456 ◽  
Author(s):  
Seyyed Abolfazl Vagharseyyedin ◽  
Bahare Zarei ◽  
Mahdi Hosseini
Keyword(s):  
Social Capital ◽  
Traumatic Stress ◽  
Secondary Traumatic Stress ◽  
Early Recognition ◽  
Compassion Satisfaction ◽  
Organisational Commitment ◽  
Cross Sectional ◽  
The One ◽  
Workplace Social Capital

Background Affective organisational commitment (AOC) refers to employees’ emotional attachment to the organisation and identification with it. It is vital that nurses explore contributors to their AOC because they stand as the largest group of employees in healthcare organisations. Aim This cross-sectional, analytical study explored the role of workplace social capital (WSC), compassion satisfaction (CS), and secondary traumatic stress (STS) in AOC in a sample of Iranian nurses. Method The study sample consisted of 250 nurses working in eight hospitals affiliated with Birjand University of Medical Sciences, eastern Iran. Participants’ WSC was measured using the Social Capital at Work Scale developed by Kouvonen et al. (2006). CS and STS were measured using CS and STS dimensions of the Professional Quality of Life measure (Version 5) developed by Stamm (2010). Results Significant positive associations were found between WSC and AOC ( p < 0.001), between the cognitive dimension of WSC and AOC ( p < 0.001), between the structural dimension of WSC and AOC ( p < 0.001), and between CS and AOC ( p < 0.001). The correlation between STS and AOC ( p < 0.001) was negatively significant. Conclusion Effort to promote WSC and CS on the one hand and prevention and early recognition of STS on the other hand can enhance nurses’ AOC.

Cerebrospinal fluid in man native to high altitude

1964 ◽  
Vol 19 (2) ◽  
pp. 319-321 ◽  
Author(s):  
J. W. Severinghaus ◽  
A. Carceleń B.
Keyword(s):  
Cerebrospinal Fluid ◽  
High Altitude ◽  
Sea Level ◽  
Regulation Of Respiration ◽  
Acid Base ◽  
Peripheral Chemoreceptor ◽  
Arterial Blood ◽  
Blood Ph ◽  
The Difference

CSF pH was shown in a prior report to remain essentially constant during 8 days of acclimatization to 3,800 m. In order to further evaluate the possible role of CSF acid-base equilibria in the regulation of respiration, 20 Peruvian Andean natives were studied at altitudes of 3,720–4,820 m. In ten subjects at 3,720 m, means were: CSF pH 7.327, Pco2 43, HCO3- 21.5, Na+ 136, K+ 2.6, Cl- 124, lactate 30 mg/100 ml. Arterial blood: pH 7.43, Pco2 32.5, HCO3- 21.3, Na+ 136, K+ 4.2, Cl- 107, hematocrit 49, SaOO2 89.6. In six subjects at 4,545 m and four at 4,820 m CSF values were not significantly different; mean arterial Pco2 was 32.6 and 32.3, respectively. The only significant variations with altitude were the expected lowering of PaOO2 to 47 and 43.5 mm Hg, and of SaOO2 to 84.2 and 80.7, and increase of hematocrit to 67% and 75%, respectively. The natives differed from recently acclimatized sea-level residents in showing less ventilation (higher Pco2) in response to the existing hypoxia, and less alkaline arterial blood. The difference appears to relate to peripheral chemoreceptor response to hypoxia rather than central medullary chemoreceptor. respiratory regulation at high altitude; chronic acclimatization to altitude; peripheral chemoreceptor response to hypoxia; CSF and medullary respiratory chemoreceptors Submitted on June 12, 1963

scholarly journals High-altitude adaptation in rhesus macaques

2020 ◽  
Author(s):  
Zachary A. Szpiech ◽  
Taylor E. Novak ◽  
Nicholas P. Bailey ◽  
Laurie S. Stevison
Keyword(s):  
Positive Selection ◽  
High Altitude ◽  
Sea Level ◽  
Local Adaptation ◽  
Convergent Evolution ◽  
Rhesus Macaques ◽  
Atmospheric Oxygen ◽  
Low Oxygen ◽  
Beneficial Mutation ◽  
Genomic Patterns

AbstractWhen natural populations split and migrate to different environments, they may experience different selection pressures that can lead to local adaptation. For aerobic life, the low atmospheric oxygen content of high altitude living presents a special challenge and a strong selection pressure. Searching for evidence of adaptation to high altitude, we compare the whole genomes of 23 wild rhesus macaques captured at high altitude (mean altitude > 4000m above sea level) to 22 wild rhesus macaques captured at low altitude (mean altitude < 500m above sea level). To capture the genomic patterns of a positive selective sweep, we develop XP-nSL, a haplotype-based genomic scan for differential local adaptation with power to detect ongoing and recently completed hard and soft sweeps. We find evidence of local adaptation in the high-altitude population at or near 303 known genes and several unannotated regions. We find the strongest signal for adaptation at EGLN1, a classic target for convergent evolution in several species living in low oxygen environments. Furthermore, many of the 303 genes are involved in processes related to hypoxia, regulation of ROS, DNA damage repair, synaptic signaling, and metabolism. These results suggest that, beyond adapting via a beneficial mutation in one single gene, adaptation to high altitude in rhesus macaques is polygenic and spread across numerous important biological systems.Impact SummaryExtreme environments pose a challenge to life on multiple fronts. Very high-altitude environments are one such example, with low atmospheric oxygen, increased ultraviolet light exposure, harsh temperatures, and reduced nutrition availability. In spite of these challenges, many plants and animals, including humans, have genetically adapted to cope with these hardships. Here we study a population of rhesus macaques living at high altitude and compare their genomic patterns with those of a population living much closer to sea level, searching for evidence of genetic changes that are indicative of adaptation to their environment.When positive selection is ongoing or a beneficial mutation has recently fixed in a population, genetic diversity is reduced in the vicinity of the adaptive allele, and we expect to observe long homozygous haplotypes at high frequency. Here we develop a statistic that summarizes these expected patterns and compares between two populations in order to search for evidence of adaptation that may have occurred in one but not the other. We implement this statistic in a popular and easy-to-use software package.We find evidence for adaptation at a critical gene that helps control physiological response to low-oxygen, one that has been the target of repeated convergent evolution across many species. We also find evidence for positive selection across a range of traits, including metabolic and neurological. This work helps to explain the evolutionary history of the rhesus macaque and furthers our understanding about the ways organisms genetically adapt to high altitude environments.

Ventilation-perfusion inequality in normal humans during exercise at sea level and simulated altitude

1985 ◽  
Vol 58 (3) ◽  
pp. 978-988 ◽  
Author(s):  
G. E. Gale ◽  
J. R. Torre-Bueno ◽  
R. E. Moon ◽  
H. A. Saltzman ◽  
P. D. Wagner
Keyword(s):  
Blood Flow ◽  
High Altitude ◽  
Sea Level ◽  
Statistical Significance ◽  
Barometric Pressure ◽  
Bicycle Ergometer ◽  
Lung Model ◽  
Inert Gas ◽  
Topographical Distribution ◽  
Normal Humans

To investigate the effects of both exercise and acute exposure to high altitude on ventilation-perfusion (VA/Q) relationships in the lungs, nine young men were studied at rest and at up to three different levels of exercise on a bicycle ergometer. Altitude was simulated in a hypobaric chamber with measurements made at sea level (mean barometric pressure = 755 Torr) and at simulated altitudes of 5,000 (632 Torr), 10,000 (523 Torr), and 15,000 ft (429 Torr). VA/Q distributions were estimated using the multiple inert gas elimination technique. Dispersion of the distributions of blood flow and ventilation were evaluated by both loge standard deviations (derived from the VA/Q 50-compartment lung model) and three new indices of dispersion that are derived directly from inert gas data. Both methods indicated a broadening of the distributions of blood flow and ventilation with increasing exercise at sea level, but the trend was of borderline statistical significance. There was no change in the resting distributions with altitude. However, with exercise at high altitude (10,000 and 15,000 ft) there was a significant increase in dispersion of blood flow (P less than 0.05) which implies an increase in intraregional inhomogeneity that more than counteracts the more uniform topographical distribution that occurs. Since breathing 100% O2 at 15,000 ft abolished the increased dispersion, the greater VA/Q mismatching seen during exercise at altitude may be related to pulmonary hypertension.

scholarly journals Glypican-3 Enhances Reprogramming of Glucose Metabolism in Liver Cancer Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Gebing Yao ◽  
Jikai Yin ◽  
Qing Wang ◽  
Rui Dong ◽  
Jianguo Lu
Keyword(s):  
Glucose Metabolism ◽  
Liver Cancer ◽  
Mitochondrial Biogenesis ◽  
Transmembrane Protein ◽  
Critical Role ◽  
Strong Line ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
The One

Glypican-3(GPC3) is a transmembrane protein which has been found to be frequently overexpressed on the surfaces of liver cancer (LC) cells, which contributes to both the growth and metastasis of LC cells. Recently, the expression of GPC3 has been reported to be inversely associated with glucose metabolism activity in LC patients, suggesting that GPC3 may play a role in the regulation of glucose metabolism in LC. However, the role of GPC3 in glucose metabolism reprogramming, as well as in LC cell growth and metastasis, is unknown. Here, we found that GPC3 significantly contributed to the reprogramming of glucose metabolism in LC cells. On the one hand, GPC3 enhanced the glycolysis of LC cells through upregulation of the glycolytic genes of Glut1, HK2, and LDH-A. On the other hand, GPC3 repressed mitochondrial respiration through downregulation of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha (PGC-1α), which has been well known as a crucial regulator in mitochondrial biogenesis. Mechanistic investigations revealed that HIF-1α was involved in both GPC3-regulated upregulation of glycolytic genes of HK2, PKM2, and Glut1 and downregulation of mitochondrial biogenesis regulator PGC-1α in LC cells. Additionally, GPC3-regulated reprogramming of glucose metabolism played a critical role in the growth and metastasis of LC cells. Conclusion. Our findings demonstrate that GPC3 is a critical regulator of glucose metabolism reprogramming in LC cells, which provides a strong line of evidence for GPC3 as an important therapeutic target to normalize glucose metabolic aberrations responsible for LC progression.

scholarly journals Rola terenowej administracji publicznej w zapobieganiu sytuacjom kryzysowym

2016 ◽  
Vol 106 ◽  
pp. 123-134
Author(s):  
Andrzej Pakuła
Keyword(s):  
Public Administration ◽  
Critical Role ◽  
Specific Area ◽  
Local Authorities ◽  
Government District ◽  
Set Up ◽  
The One ◽  
Executive Officers ◽  
Council Of Ministers

THE ROLE OF LOCAL PUBLIC ADMINISTRATION IN PREVENTING CRISIS SITUATIONSCrisis management is a specific area of public safety protection. Competent authorities in this area include on the one hand, Council of Ministers and on the other, territorial local authorities belonging both to local administration voivodes and local government district governors and municipal executive officers/town mayors/city presidents. The territorial local authorities play a critical role here as they are a specific structure set up for crisis management.

Sign in / Sign up

Export Citation Format

Share Document