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Biomedical subjects

O Oelz

Publications and source records attributed to O Oelz.

At least 55 records · Page 3Linked to original sources
PubMed1991

Enhanced exercise-induced rise of aldosterone and vasopressin preceding mountain sickness.

A possible contribution of exercise to the fluid retention associated with acute mountain sickness (AMS) was investigated in 17 mountaineers who underwent an exercise test for 30 min on a bicycle ergometer with a constant work load of 148 +/- 9 (SE) W at low altitude (LA) and with 103 +/- 6 W 4-7 h after arrival at 4,559 m or high altitude (HA). Mean heart rates during exercise at both altitudes and during active ascent to HA were similar. Exercise-induced changes at LA did not differ significantly between the eight subjects who stayed well and the nine subjects who developed AMS during a 3-day sojourn at 4,559 m. At HA, O2 saturation before (71 +/- 2 vs. 83 +/- 2%, P less than 0.01) and during exercise (67 +/- 2 vs. 72 +/- 1%, P less than 0.025) was lower and exercise-induced increase of plasma aldosterone (617 +/- 116 vs. 233 +/- 42 pmol/l, P less than 0.025) and plasma antidiuretic hormone (23.8 +/- 14.4 vs. 3.4 +/- 1.8 pmol/l, P less than 0.05) was greater in the AMS group, whereas exercise-induced rise of plasma atrial natriuretic factor and changes of hematocrit, potassium, and osmolality in plasma were similar in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1991

Blood rheology in acute mountain sickness and high-altitude pulmonary edema.

The role of blood rheology in the pathogenesis of acute mountain sickness and high-altitude pulmonary edema was investigated. Twenty-three volunteers, 12 with a history of high-altitude pulmonary edema, were studied at low altitude (490 m) and at 2 h and 18 h after arrival at 4,559 m. Eight subjects remained healthy, seven developed acute mountain sickness, and eight developed high-altitude pulmonary edema. Hematocrit, whole blood viscosity, plasma viscosity, erythrocyte aggregation, and erythrocyte deformability (filtration) were measured. Plasma viscosity and erythrocyte deformability remained unaffected. The hematocrit level was lower 2 h after the arrival at high altitude and higher after 18 h compared with low altitude. The whole blood viscosity changed accordingly. The erythrocyte aggregation was about doubled 18 h after the arrival compared with low-altitude values, which reflects the acute phase reaction. There were, however, no significant differences in any rheological parameters between healthy individuals and subjects with acute mountain sickness or high-altitude pulmonary edema, either before or during the illness. We conclude that rheological abnormalities can be excluded as an initiating event in the development of acute mountain sickness and high-altitude pulmonary edema.

Acute Disease↗
PubMed1991

Effects of slow ascent to 4559 M on fluid homeostasis.

Since acute mountain sickness (AMS) is associated with rapid ascent and with fluid retention, we assessed clinical status and fluid homeostasis in men slowly ascending on foot over 3 d to 4559 m and remaining at this altitude 5 d. We studied 15 male mountaineers, 6 of whom had previously had repeated, severe AMS or high altitude pulmonary edema (HAPE), at 1170 m, 3611 m, and 4559 m. We found that four of the six subjects with previous AMS or HAPE compared with none of nine with no such history, developed these conditions. Those who remained well had a diuresis that could not be overcome by increasing fluid intake and no change in renin activity, plasma aldosterone, or atrial natriuretic peptide (ANP). Those who became ill showed considerable weight gain independent of fluid intake, and a great increase in ANP which correlated with measurements of right atrial cross section. We conclude that mountaineers who have previously experienced repeated AMS or HAPE get fluid retention despite slow ascent and that this is associated with widening of the atrium and an increase in ANP.

Adult↗
PubMed1991

Cognitive changes at high altitude in healthy climbers and in climbers developing acute mountain sickness.

We report the cognitive functions of 17 non-acclimatized mountaineers who ascended from low lands to an altitude of 4,559 m in 24 h and were studied there within 6 h. We found that this rapid ascent to high altitude had small, but differential effects upon cognitive performance depending upon the later development of acute mountain sickness (AMS). Subjects who developed AMS within a 24-48-h stay at high altitude were mildly impaired in short term memory, but improved in conceptual tasks, while subjects who remained healthy had a better short term memory performance but no improvement in cognitive flexibility. Possible explanations for these unexpected effects of high altitude are discussed.

Adult↗
PubMed1990

Prevalence of acute mountain sickness in the Swiss Alps.

OBJECTIVE: To assess the prevalence of symptoms and signs of acute mountain sickness of the Swiss Alps. DESIGN: A study using an interview and clinical examination in a representative population of mountaineers. Positive symptoms and signs were assigned scores to quantify the severity of acute mountain sickness. SETTING: Four huts in the Swiss Alps at 2850 m, 3050 m, 3650 m, and 4559 m. SUBJECTS: 466 Climbers, mostly recreational: 47 at 2850 m, 128 at 3050 m, 82 at 3650, and 209 at 4559 m. RESULTS: In all, 117 of the subjects were entirely free of symptoms and clinical signs of acute mountain sickness; 191 had one or two symptoms and signs; and 158 had more than two. Those with more than two symptoms and signs were defined as suffering from acute mountain sickness. At 4559 m 11 climbers presented with high altitude pulmonary oedema or cerebral oedema, or both. Men and women were equally affected. The prevalence of acute mountain sickness correlated with altitude: it was 9% at 2850 m, 13% at 3050 m, 34% at 3650 m, and 53% at 4559 m. The most frequent symptoms and signs were insomnia, headache, peripheral oedema, and scanty pulmonary rales. Severe headache, vomiting, dizziness, tachypnoea, and pronounced pulmonary rales were associated with other symptoms and signs and therefore characteristic of acute mountain sickness. CONCLUSION: Acute mountain sickness is not an uncommon disease at moderately high altitude--that is, above 2800 m. Severe headache, vomiting, dizziness, tachypnoea, and pronounced pulmonary rales indicate severe acute mountain sickness, and subjects who suffer these should immediately descend to lower altitudes.

Acute Disease↗
PubMed1990

Comparison of carbon-dioxide-enriched, oxygen-enriched, and normal air in treatment of acute mountain sickness.

Twenty mountaineers with acute mountain sickness (AMS) at an altitude of 4559 m were randomly allocated to treatment with oxygen-enriched (33% oxygen), carbon-dioxide-enriched (3% carbon dioxide), or normal compressed air. Treatment with oxygen significantly improved the arterial partial pressure of oxygen (PaO2), relieved symptoms of AMS, and reduced cerebral blood flow as estimated by transcranial doppler ultrasound examination of the median cerebral artery. The only significant effect of carbon dioxide was increased ventilation resulting in a slight rise in PaO2. Thus, in contrast to previous uncontrolled trials, this study does not support the usefulness of carbon dioxide treatment in AMS.

Acute Disease↗
PubMed1990

[Permeability pulmonary edema in pheochromocytoma].

We describe two patients with pheochromocytoma who developed pulmonary edema of rapid onset. The edema occurred spontaneously in the first case and during surgery for the tumor in the second patient. Since left ventricular function was normal in both patients and the protein content of the edema fluid was elevated in one patient, the conditions involved were permeability edemas.

Adrenal Gland Neoplasms↗
PubMed1990

Pure red cell aplasia of long duration complicating major ABO-incompatible bone marrow transplantation.

In 3 of 15 consecutive patients receiving a human leukocyte antigen (HLA)-identical but major ABO incompatible bone marrow transplant (BMT), pure red cell aplasia (PRA) lasting 5 to 8 months was observed. Titers of the incompatible anti-A agglutinin before infusion of the red blood cell (RBC)-depleted BMT was very high in one, and in the usual range in two patients. Decrease of agglutinin titers during the first 4 weeks after BMT were comparable between PRA patients and those of ABO-incompatible BMT recipients with timely RBC recovery. However, in PRA patients, agglutinin titers rose again and remained elevated for 19 to 28 weeks. RBC engraftment and reticulocyte recovery ultimately occurred spontaneously and coincided with the decrease of agglutinin titers below 16. These observations indicate that PRA is antibody-dependent in this setting. Furthermore, it is conceivable that cyclosporine facilitates recipient-derived antibody synthesis after major ABO-incompatible BMT.

ABO Blood-Group System↗
PubMed1990

Unchanged in vivo P50 at high altitude despite decreased erythrocyte age and elevated 2,3-diphosphoglycerate.

We measured hematological and erythrocyte O2 transport parameters in whole blood and density-separated erythrocytes in 11 mountaineers before and during 5 days of exposure to high altitude (4,559 m). We determined the in vivo (arterial pHblood and PCO2) and standard (pHblood = 7.4, PCO2 = 40 Torr) O2 tension at 50% O2 saturation of hemoglobin and (P50,vv and P50,st) and Bohr coefficients (BC) for fixed acid (H+) and CO2 and examined the contribution of the altered average age of circulating erythrocytes due to the stimulation of erythropoiesis on whole blood 2,3-diphosphoglycerate (2,3-DPG) and P50,st. At altitude, whole blood P50,vv remained almost unchanged, whereas P50,st and 2,3-DPG increased significantly (+4 Torr; 3.5 mumol/g hemoglobin). BCCO2 was elevated significantly at altitude. Serum erythropoietin increased transiently fourfold, iron utilization increased, and serum iron decreased by 66%. Reticulocyte counts increased, but other hematological parameters were unchanged. In density-separated erythrocytes, P50,st and 2,3-DPG increased with decreasing cell density but were higher in fractions with comparable reticulocyte counts in cells prepared at altitude than in those from control studies. Our data show that, despite the increase in 2,3-DPG and the decrease in average erythrocyte age, the in vivo hemoglobin-O2 affinity remains unchanged. P50,st values reflect the elevation of 2,3-DPG, and approximately 50% of the increase in both parameters can be ascribed to the increase in the number of reticulocytes and young erythrocytes.

2,3-Diphosphoglycerate↗
PubMed1990

[Adventure and survival trips: possible medical problems].

Commercially available adventure and survival trips usually do not involve any serious health risks. Serious adventurous journeys lead into the great deserts, jungles and to extreme altitude and involve a whole spectrum of risks, depending on climate, latitude and inhabitants of the area. Survival is determined by the experience and the determination of the explorer of the unknown.

Altitude Sickness↗
PubMed1990

[Aspirin against aging? For whom and how much?].

Aspirin has been successfully used in the secondary prophylaxis of myocardial infarction, cerebral vascular events and peripheral arterial disease. Regular aspirin intake may further be beneficial in asymptomatic healthy male with cardiovascular risk factors over the age of 50. There is no good evidence that aspirin prevents the development of atherosclerosis and thromboembolic events in healthy individuals.

Arachidonic Acids↗
PubMed1989

Nifedipine for high altitude pulmonary oedema.

In a laboratory at 4559 m six subjects with high altitude pulmonary oedema (HAPO) characterised by clinical signs, severe hypoxaemia, widened alveolar-arterial oxygen gradient, pulmonary hypertension, and alveolar oedema on chest radiography were treated with nifedipine. Despite continued exercise at the same altitude this treatment, without supplementary oxygen, resulted in clinical improvement, better oxygenation, reduction of alveolar arterial oxygen gradient and pulmonary artery pressure, and progressive clearing of alveolar oedema. Nifedipine offers a potential emergency treatment for HAPO when descent or evacuation is impossible and oxygen is not available. The findings also suggest that hypoxic pulmonary hypertension is essential in the pathogenesis of HAPO.

Acute Disease↗
PubMed1989

[Decrease in systemic fungal infections in hematological neoplasms with empirical use of amphotericin B therapy].

An incidence of up to 30% of systemic fungal infections at autopsy, and difficulties in diagnosing systemic mycosis antemortem, have led to the empiric use of amphotericin B in patients with hematological malignancies. Routine empiric anti-fungal treatment was initiated at our institution in 1982. Amphotericin B and initially for 3 days flucytosine was given to granulocytopenic patients with unremitting (after 48-72 h) or recurrent fever during antibiotic treatment, or with newly detected pulmonary infiltrates, sinusitis, and skin and retinal lesions suggestive of fungal infection. With this approach the rate of systemic fungal infections decreased from 10% to 4% (p less than 0.02). The reduction was most prominent in patients with acute myelogenous leukemia, where fungal infections decreased from 16% to 4% (p less than 0.025).

Amphotericin B↗