Hemoglobin at High Altitude as Related to Age

1963 ◽  
Vol 9 (6) ◽  
pp. 710-716 ◽  
Author(s):  
D B Dill ◽  
J W Terman ◽  
F G Hall
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Blood Volume ◽  
Early Phase ◽  
Hemoglobin Concentration ◽  
The Other ◽  
Other Hand

Abstract During the summer of 1962 the early phase of acclimatization to high altitude was studied in 6 of those who participated in the international high-altitude expedition to Chile in 1935. Ages of the 6 ranged from 58 to 71. Two also had taken part in a high-altitude study in 1929. In their earlier years these subjects had had an increase in hemoglobin concentration beginning with their arrival at high altitude. This response has been well established, especially by the Pike's Peak party led by Haldane and the work of Hurtado and associates in Peru. On the other hand, 5 of the 6 in the 1962 party exhibited a decrease in hemoglobin concentration during the first few days. The greatest decrease was observed in the oldest subject. His hemoglobin was 88% of his sea level value after 9 days at altitude and remained below his sea level value for another week. No observations were made on blood volume; hence, we can only speculate regarding possible related changes.

The growth of children at different altitudes in Ethiopia

1972 ◽  
Vol 264 (864) ◽  
pp. 403-437 ◽  
Keyword(s):  
Infectious Disease ◽  
Ambient Temperature ◽  
High Altitude ◽  
Sea Level ◽  
The Other ◽  
Skeletal Maturation ◽  
Early Puberty ◽  
Other Hand ◽  
The World ◽  
Different Altitudes

In this study were observed the effects of two widely differing environments on the growth and maturation of children from a presumed genetically homogeneous Ethiopian population. Major environmental differences included altitude above sea level, temperature, probably rainfall and humidity, together with the incidence of infectious disease. The results indicate that highland children, particularly boys, are taller, heavier and bigger in most physical dimensions than are lowland children. In both groups skeletal maturation is retarded (by American White standards) during later childhood; this retardation is more marked in lowlanders. In both groups, however, there is marked acceleration of skeletal maturation during early puberty. Haemoglobin values increase much more rapidly in highland children, but surprisingly, differences in chest dimensions are not particularly marked. It is concluded that hypoxia of the degree found in the high-altitude group (approximately 3000 m) is not sufficient to affect adversely the growth of children. On the other hand, the increased incidence of infectious disease in the ‘lowlands’ (approximately 1500 m) and possibly the raised ambient temperature, may restrict growth and maturation of children living in this environment. Thus, in contrast to the situation in other high-altitude parts of the world, the highlands in Ethiopia appear to be more favourable to growth than the lowlands.

scholarly journals The overlooked significance of plasma volume for successful adaptation to high altitude in Sherpa and Andean natives

2019 ◽  
Vol 116 (33) ◽  
pp. 16177-16179 ◽  
Author(s):  
Mike Stembridge ◽  
Alexandra M. Williams ◽  
Christopher Gasho ◽  
Tony G. Dawkins ◽  
Aimee Drane ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Exercise Capacity ◽  
Blood Volume ◽  
Plasma Volume ◽  
Hemoglobin Concentration ◽  
Genomic Research ◽  
Total Blood ◽  
Functional Relevance ◽  
Hemoglobin Mass

In contrast to Andean natives, high-altitude Tibetans present with a lower hemoglobin concentration that correlates with reproductive success and exercise capacity. Decades of physiological and genomic research have assumed that the lower hemoglobin concentration in Himalayan natives results from a blunted erythropoietic response to hypoxia (i.e., no increase in total hemoglobin mass). In contrast, herein we test the hypothesis that the lower hemoglobin concentration is the result of greater plasma volume, rather than an absence of increased hemoglobin production. We assessed hemoglobin mass, plasma volume and blood volume in lowlanders at sea level, lowlanders acclimatized to high altitude, Himalayan Sherpa, and Andean Quechua, and explored the functional relevance of volumetric hematological measures to exercise capacity. Hemoglobin mass was highest in Andeans, but also was elevated in Sherpa compared with lowlanders. Sherpa demonstrated a larger plasma volume than Andeans, resulting in a comparable total blood volume at a lower hemoglobin concentration. Hemoglobin mass was positively related to exercise capacity in lowlanders at sea level and in Sherpa at high altitude, but not in Andean natives. Collectively, our findings demonstrate a unique adaptation in Sherpa that reorientates attention away from hemoglobin concentration and toward a paradigm where hemoglobin mass and plasma volume may represent phenotypes with adaptive significance at high altitude.

The Influence of Altitude on Erythropoietin Resistance Index in Maintenance Hemodialysis Patients: Data from Tibetan Plateau

2020 ◽  
pp. 1-6
Author(s):  
Yan Wang ◽  
Zong-hui Dang ◽  
Liang-ying Gan ◽  
Ciren Luobu ◽  
Lei Zhang ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Resistance Index ◽  
Hemoglobin Concentration ◽  
Maintenance Hemodialysis ◽  
Autonomous Region ◽  
Tibet Autonomous Region ◽  
Dialysis Vintage ◽  
Peking University ◽  
The Impact

Background: It is known that hypoxia influences many of the biologic processes involved in erythropoiesis; therefore, the high-altitude hypoxia may affect erythropoietin (EPO) responsiveness in maintenance hemodialysis (MHD) patients. This study aimed to evaluate the impact of altitude on EPO responsiveness in MHD patients. Methods: In this retrospective study, MHD patients from Tibet Autonomous Region People’s Hospital (3,650 m above sea level) and Peking University People’s Hospital (43.5 m above sea level) were recruited between May 2016 and December 2018. Patients were divided into 2 groups according to altitude. Variables including age, sex, dialysis vintage, dialysis modality, duration of EPO use, EPO doses, and laboratory tests were collected and analyzed. EPO responsiveness was measured in terms of the EPO resistance index (ERI). ERI was defined as the weekly weight-adjusted dose of EPO (IU/kg/week) divided by hemoglobin concentration (g/dL). The association between ERI and altitude was estimated using a multivariable linear regression model. Results: Sixty-two patients from Tibet Autonomous Region People’s Hospital (high-altitude [HA] group) and 102 patients from Peking University People’s Hospital (low-altitude [LA] group) were recruited. The ERI for HA group and LA group was 6.9 ± 5.1 IU w−1 kg−1 (g/dL)−1 and 11.5 ± 6.4 IU w−1 kg−1 (g/dL)−1, respectively. After adjusting for covariates by multivariable regression, altitude was independently associated with ERI (R2 = 0.245, p < 0.001). Conclusion: Altitude had an independent negative correlation with ERI. This result supported the hypothesis that altitude-associated hypoxia improved EPO responsiveness in MHD patients.

Ampleur des regressions glacioeustatiques

1954 ◽  
Vol S6-IV (4-6) ◽  
pp. 243-254 ◽  
Author(s):  
Andre Cailleux
Keyword(s):  
Sea Level ◽  
The Other ◽  
Submarine Canyons ◽  
Isostatic Compensation ◽  
Zero Level ◽  
Ice Caps ◽  
Quaternary Glaciation ◽  
Other Hand

Abstract With allowance for isostatic compensation, the maximum lowering of sea level due to Quaternary glaciation is calculated to be 90 to 150 m with respect to present zero level. This is insufficient to explain submarine canyons. The more extensive Precambrian ice caps, on the other hand, could have lowered the sea by the required amount.

Effect of a submerged reef chain on periods of sea-level oscillations in Western Australia

1980 ◽  
Vol 31 (6) ◽  
pp. 719 ◽  
Author(s):  
EO Tuck ◽  
H Allison ◽  
SR Field ◽  
JW Smith
Keyword(s):  
Sea Level ◽  
Western Australia ◽  
Deep Water ◽  
Bottom Topography ◽  
The Other ◽  
Partial Obstruction ◽  
Other Hand ◽  
Level Oscillation ◽  
Sea Level Oscillations ◽  
Significant Step

A seiching type of sea-level oscillation recorded in Western Australia by Allison and Grassia (1979) is influenced by a submerged reef chain parallel to the shore. Being submerged, the reef chain forms an obstruction, causing the water between it and the shore to be partly open to the ocean. The effect of such a partial obstruction is studied in this paper, both theoretically and experimentally. Results indicate that even a comparatively small gap above the reef chain gives rise to periods of oscillations close to that of a fully open basin. On the other hand, presence of a comparatively smalI reef gives rise to seiching with periods nearly of the fully open basin, even in the case of the absence of a significant step to deep water in the bottom topography beyond the reef chain.

Effects of erythrocyte infusion on VO2max at high altitude

1996 ◽  
Vol 81 (1) ◽  
pp. 252-259 ◽  
Author(s):  
A. J. Young ◽  
M. N. Sawka ◽  
S. R. Muza ◽  
R. Boushel ◽  
T. Lyons ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Carrying Capacity ◽  
Hemoglobin Concentration ◽  
Treadmill Running ◽  
Control Group ◽  
O2 Uptake ◽  
Control Subjects ◽  
And Control ◽  
Experimental Group

This study investigated whether autologous erythrocyte infusion would ameliorate the decrement in maximal O2 uptake (VO2max) experienced by lowlanders when they ascend to high altitude. VO2max was measured in 16 men (treadmill running) at sea level (SL) and on the 1st (HA1) and 9th (HA9) days of high-altitude (4,300 m) residence. After VO2max was measured at SL, subjects were divided into two matched groups (n = 8). Twenty-four hours before ascent to high altitude, the experimental group received a 700-ml infusion of autologous erythrocytes and saline (42% hematocrit), whereas the control group received only saline. The VO2max of erythrocyte-infused [54 +/- 1 (SE) ml.kg-1.min-1] and control subjects (52 +/- 2 ml.kg-1.min-1) did not differ at SL before infusion. The decrement in VO2max on HA1 did not differ between groups, averaging 26% overall, despite higher (P < 0.01) arterial hematocrit, hemoglobin concentration, and arterial O2 content in the erythrocyte-infused subjects. By HA9, there were no longer any differences in hematocrit, hemoglobin concentration, or arterial O2 content between groups. No change in VO2max occurred between HA1 and HA9 for either group. Thus, despite increasing arterial O2-carrying capacity, autologous erythrocyte infusion did not ameliorate the decrement in VO2max at 4,300-m altitude.

scholarly journals Impactos ambientales generados por la actividad deportiva, recreativa y turística en alta montaña. Análisis de la cordillera de la Región Metropolitana de Santiago, Chile (Environmental impact generated by sports, recreation, and tourism activities in hi

Retos ◽  
2019 ◽  
pp. 62-69
Author(s):  
Pablo Rebolledo Dujisin
Keyword(s):  
Environmental Management ◽  
Environmental Impact ◽  
High Altitude ◽  
Decision Makers ◽  
The Other ◽  
High Mountain ◽  
Qualitative And Quantitative ◽  
Other Hand ◽  
Surprising Finding ◽  
Recreation And Tourism

El objetivo del estudio consiste en aportar el conocimiento de los efectos generados por la actividad deportiva y la recreación en alta montaña, para fortalecer la gestión y la disminución de los impactos indeseables. El método ha consistido en la aplicación de una herramienta cualitativa y una cuantitativa: una encuesta a los actores relevantes dentro del mundo actividades recreativas de alta montaña y una adaptación de la Matriz de Leopold en senderos, campamentos y cumbres de dos sectores de práctica del deporte de alta montaña en la zona central de Chile; la revisión bibliográfica permite comprender, por otra parte, el fenómeno y destacar las iniciativas de las federaciones internacionales de actividades deportivas de montaña para la gestión ambiental. Llama la atención, como conclusión de la encuesta, la percepción del deporte de alta montaña como una actividad inocua que genera impactos despreciables y, por otra parte, destaca en los resultados de la Matriz de Leopold la concentración de desperdicios, los efectos de las tiendas de campaña y los baños improvisados, afectando principalmente a las fuentes de agua y al suelo. Lo que conlleva una situación donde los tomadores de decisión no son conscientes de los efectos y, por lo tanto, no están tomando las medidas adecuadas para su control.Abstract. The objective of the study is to provide knowledge about the effects generated by sports and recreation in high altitude mountains, to strengthen their management and decrease their undesirable impacts. The method consisted in the application of qualitative and quantitative tools: a survey to stakeholders, and an adaptation of the Leopold Matrix on trails, camps and summits in two areas for high altitude sport in the central region of Chile; on the other hand, bibliographic review allows to understand this phenomenon, and highlight the initiatives of international federations of mountain sports for better environmental management. As a conclusion of the survey, a surprising finding is that high mountain sports are perceived as innocuous activities that generate negligible impacts; on the other hand, concentration of waste, and effects of tents and improvised toilets stand out as main results from the Leopold Matrix, mainly affecting water sources and soil. This demonstrates that decision makers are not aware of the effects of mountain sports and, therefore, they are not taking appropriate measures to control them.

Function 2: Social, Economic, Ritual

2012 ◽  
Author(s):  
Dennis Harding
Keyword(s):  
High Altitude ◽  
Iron Age ◽  
Environmental Conditions ◽  
The Other ◽  
Ample Evidence ◽  
Southern England ◽  
Other Hand ◽  
First Millennium ◽  
Seasonal Basis ◽  
Wall Construction

In southern England, in terms of prevailing environmental conditions most hillforts could have been occupied or used on a permanent rather than seasonal basis. With the exception of Exmoor and Dartmoor in the far south-west, none are located above the 300m contour and therefore could potentially have sustained a mixed agricultural regime. In northern England, Wales, and Scotland, on the other hand, there are hillforts at altitudes that make seasonal use more likely, although even with some of the larger hillforts in southern Scotland and Northumberland, like Eildon Hill, Hownam Law, and Yeavering Bell, higher altitude may not have precluded occupation on a significant scale. We have already seen that some hillforts in southern Scotland and the Cheviots show ample evidence of occupation in the form of house stances, so that a residential function as a primary purpose is hardly in doubt. Sites like Hayhope Knowe or Camp Tops may be categorized as protected villages, and though some might seem scarcely to qualify as hillforts at all (Frodsham et al. 2007), others like Sundhope Kipp boast defensive earthworks, which seem almost disproportionate in scale to the area of the internal settlement. Sometimes the houses are so densely arranged within the interior as to exclude the possibility of division into different activity zones, unless some of these seemingly identical roundhouses actually served as workshops or stores rather than just for domestic occupation. Despite their relatively high altitude and exposed locations, there is every reason to believe that some sites were permanently occupied, since evidence of cord-rig agriculture often lies in immediate proximity to the enclosure. Even so, these cultivation plots must have been on the margins of viability in the Iron Age, and it is possible that these Borders upland sites by the later first millennium BC were used only seasonally. Indeed, progressive environmental deterioration may be a reason why the earthwork phase of enclosure at Hayhope Knowe was never completed. Archaeologically it is hard to point to evidence that might distinguish seasonal from permanent occupation. The number of buildings may be indicative of the intensity of use, but might stake-wall construction with numerous episodes of rebuilding indicate seasonal construction, as opposed to more permanent post-built houses? On the other hand, stone foundations could have been renovated seasonally in a manner than might be hard to distinguish archaeologically from permanent use.

scholarly journals The Polycythemia of High Altitudes: Iron Metabolism and Related Aspects

Blood ◽  
1959 ◽  
Vol 14 (4) ◽  
pp. 433-455 ◽  
Author(s):  
CÉSAR REYNAFARJE ◽  
RODOLFO LOZANO ◽  
JOSÉ VALDIVIESO
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Blood Volume ◽  
Turnover Rate ◽  
Cell Mass ◽  
Red Cells ◽  
Red Cell ◽  
Turnover Rates ◽  
High Altitudes ◽  
Total Blood

Abstract Observations on the iron metabolism as related to the influence of a low oxygen tension at high altitudes, and after the disappearance of this factor upon return to sea level, have been made in human subjects. They consisted mainly of studies of intestinal absorption and turnover rate of iron by means of the radioactive isotope of this metal (Fe-59). Additional observations were made on blood volume, reticulocytosis, bone marrow cytology, life span of the red cells and hemoglobin breakdown pigments. The data obtained seem to justify the following conclusions: 1. There is an increase of intestinal iron absorption during the early period of exposure to an altitude of 14,900 feet. After 48 hours of exposure, this was estimated to be about 3 times higher than the absorption observed in subjects at sea level and in native residents at the above-mentioned altitude. 2. There is an increase of plasma and red cell iron turnover rates after 2 hours of arrival to 14,900 feet, indicating that the increase in the production of red cells, to compensate for hypoxia, is a very early response. 3. The highest increase in plasma and red cell iron turnover rate takes place 7 to 14 days after exposure to high altitude begins. After six months of exposure, there is still an elevated iron turnover rate. The native residents of high altitudes (14,900 feet) have a red cell iron turnover rate of approximately 30 per cent higher than healthy subjects at sea level. 4. A progressive decrease in the plasma and red cell iron turnover rate is observed in native residents of high altitudes when brought down to sea level, the maximum of which is reached after two to five weeks, indicating a great degree of depression on red cell production. After that, a gradual return to normal rate is observed in the weeks that follow. 5. The degree of reticulocytosis is in close relationship with changes in the red cell iron turnover rates. 6. Changes in the total blood volume, either during ascent or descent, take place only after several weeks. The red cell mass variations which occur during the early periods of environmental change, are compensated by proportional changes in the plasma volume. The increase or decrease of the total blood volume after this period is due exclusively to red cell mass modifications. 7. The bone marrow cytologic studies carried out in subjects temporarily exposed or living permanently at high altitudes show a hyperplastic condition. The reverse, or an inhibition of red cell production, takes place when high altitude polycythemic subjects are brought down to sea level. This constitutes the cytologic counter-proof for the iron turnover studies. 8. The life span of the red blood cells, after descent from high altitudes to sea level, falls within normal patterns. However, by the method employed it is not possible to determine if there is an increased destruction of red cells during the first week. But if there is a greater destruction, this would be of a small degree, affecting only the older elements. The increase in the hemoglobin breakdown pigments, which occurs under the influence of environmental factors, is also discussed. 9. In native residents of high altitudes the amount of free erythroprotoporphyrins is higher than in residents at sea level. The erythroprotoporphyrins in newcomers to high altitudes rise and reach a peak at the end of the second month, followed by a gradual decline. On the other hand, when high altitude natives are brought down to sea level, a marked decrease in erythroprotoporphyrins is noted. The rate of decrease is highest within the first months.

Investigating the early phase of the galaxy evolution through high-z damped Lyα absorption systems

2019 ◽  
Vol 15 (S341) ◽  
pp. 294-296
Author(s):  
Kazuyuki Ogura ◽  
Tohru Nagao ◽  
Masatoshi Imanishi ◽  
Nobunari Kashikawa ◽  
Yoshiaki Taniguchi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Galaxy Evolution ◽  
Early Phase ◽  
Luminosity Function ◽  
The Other ◽  
Other Hand ◽  
The Galaxy

AbstractWe present the physical properties of Lyα emitters (LAEs) in a “DLA-concentrated regions” where there are 3 or more DLA within (50 Mpc)3 cubic box. We observed LAEs in a DLA-concentrated region at z = 2.3, the J1230+34 field, with Subaru/Suprime-Cam. In the 50 Mpc scale, we found no deferences in properties of LAEs such as Lyα luminosity function in the DLA-concentrated region compared to other fields at similar redshift. On the other hand, we found a ∼10 Mpc scale LAE overdensity around a strong DLA with NHI = 1021.08 cm−2.

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