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Dieter Böning

Publications and source records attributed to Dieter Böning.

10 recordsLinked to original sources
PubMed2006

Causes of differences in exercise-induced changes of base excess and blood lactate.

It has been concluded from comparisons of base excess (BE) and lactic acid (La) concentration changes in blood during exercise-induced acidosis that more H+ than La- leave the muscle and enter interstitial fluid and blood. To examine this, we performed incremental cycle tests in 13 untrained males and measured acid-base status and [La] in arterialized blood, plasma, and red cells until 21 min after exhaustion. The decrease of actual BE (-deltaABE) was 2.2 +/- 0.5 (SEM) mmol l(-1) larger than the increase of [La]blood at exhaustion, and the difference rose to 4.8 +/- 0.5 mmol l(-1) during the first minutes of recovery. The decrease of standard BE (SBE), a measure of mean BE of interstitial fluid (if) and blood, however, was smaller than the increase of [La] in the corresponding volume (delta[La](if+blood)) during exercise and only slightly larger during recovery. The discrepancy between -deltaABE and delta[La]blood mainly results from the Donnan effect hindering the rise of [La]erythrocyte to equal values like [La]plasma. The changing Donnan effect during acidosis causes that Cl- from the interstitial fluid enter plasma and erythrocytes in exchange for HCO3(-). A corresponding amount of La- remains outside the blood. SBE is not influenced by ion shifts among these compartments and therefore is a rather exact measure of acid movements across tissue cell membranes, but changes have been compared previously to delta[La]blood instead to delta[La](if+blood). When performing correct comparisons and considering Cl-/HCO3(-) exchange between erythrocytes and extracellular fluid, neither the use of deltaABE nor of deltaSBE provides evidence for differences in H+ and La- transport across the tissue cell membranes.

Acid-Base Equilibrium↗
PubMed2006

Intravascular hemolysis and mean red blood cell age in athletes.

PURPOSE: Since the observation that mechanical stress causes red blood cell (RBC) destruction, foot-strike hemolysis has been used to explain sports anemia and RBC rejuvenation in athletes. Recently gained knowledge questions the importance of mechanical RBC trauma on RBC hemolysis in athletes. METHODS: Male athletes (N = 90) and untrained male controls (N = 58) were investigated for aerobic performance, hematological parameters, serum erythropoietin concentration (EPO), soluble transferrin receptor concentration (sTFR), and erythrocyte aspartate aminotransferase activity (eAST). RESULTS: On hard floor running disciplines (HFR, N = 26, short- and long-distance runners, triathletes) showed a lower eAST (P < 0.001) and thus no younger RBC population than not on hard floor running athletes (NHFR, N = 64, cyclists, soccer players, others) or the untrained control group (N = 58). HFR had higher but still normal EPO (P < 0.01) and no higher sTFR. CONCLUSION: Because intravascular hemolysis occurs in swimmers, cyclists, and runners, and mean RBC age is not reduced in runners, mechanisms other than foot-strike hemolysis have to be considered as well. Possible reasons are intramuscular destruction, osmotic stress, and membrane lipid peroxidation caused by free radicals released by activated leukocytes. Intravascular hemolysis can even be regarded as physiological means to provide heme and proteins for muscle growth.

Adolescent↗
PubMed2004

An optimized method for the assay of the red blood cell--age-related enzyme aspartate aminotransferase.

Three methods of preparation of red blood cell concentrate for erythrocyte aspartate aminotransferase measurement were compared: (1) filtration of whole blood through a cellulose column (n = 36); (2) washing of whole blood and aspiration of buffy coat after centrifugation (n = 48); (3) optimized method with washing without aspiration of buffy coat (n = 229).

Aspartate Aminotransferases↗
PubMed2003

Effects of endurance training on the physical performance of patients with hematological malignancies during chemotherapy.

Fatigue and impaired physical performance are common and sometimes serious problems of cancer patients during and after treatment. To avoid fatigue, cancer patients are often advised to rest and downregulate their daily activities. However, these recommendations can cause paradoxical results. Since inactivity induces muscular wasting, prolonged rest can result in further loss of endurance. Recent studies suggest that exercise, as well as behavioral and some psychosocial interventions, may reduce fatigue and improve the performance status of cancer patients. In this paper, we review interventions proposed for the treatment of cancer-related fatigue and present the results of a study about the effects of exercise on the physical performance of patients with hematological malignancies. Sixty-six inpatients (34 men, 32 women) undergoing conventional ( n=45) or high-dose chemotherapy with stem cell rescue ( n=21) for the treatment of a hematological malignancy exercised daily on a treadmill. Physical performance was assessed on admission and once a week during hospitalization (30+/-10 days, range 10-49). Physical performance remained unchanged in a submaximal standard stress test (on admission: 5.5+/-1.4 km/h; midhospitalization: 5.3+/-1.3 km/h; at discharge: 5.5+/-1.3 km/h; p=0.60) despite chemotherapy and its related complications. A significant decrease in the mean hemoglobin concentration (from 10.3+/-2.0 g/dl on admission to 9.6+/-1.2 g/dl at discharge; p=0.03). We conclude that a daily endurance-training program reduces the treatment-related loss of physical performance in patients with hematological malignancies undergoing chemotherapy.

Adult↗
PubMed2003

[Sore muscles].

Explore the source record for details and available documents.

Exercise↗
PubMed2002

Effect of growth hormone on exercise tolerance in children with cystic fibrosis.

PURPOSE: The effect of growth hormone (GH) treatment on exercise tolerance in children with cystic fibrosis was investigated. METHODS: 10 prepubertal children (mean +/- SD; age: 12.1 +/- 1.7 yr; height: 137.4 +/- 9.2 cm; body mass: 27.8 +/- 4.2 kg; forced expiratory volume in 1 s (FEV1): 68 +/- 22% predicted) were randomly assigned to either control period (CON, standard therapy) or recombinant human growth hormone (GH) period (additional GH treatment, 0.11-0.14 IU.kg-1, daily, s.c.) for the first 6 months, and then assigned to the other period for the next 6 months. At study entry and after each period, anthropometric data, pulmonary function, and exercise capacity (peak exercise capacity, .VO(2peak), and isokinetic muscle strength) were measured. RESULTS: Changes in height (+4.3 +/- 1.0 cm), total body mass (+2.2 +/- 0.8 kg), and lean body mass (LBM, +2.9 +/- 0.7 kg) were significantly higher (P < 0.01) after GH treatment compared with CON. Pulmonary function did not significantly change in either of the periods. In contrast to CON, GH treatment improved absolute .VO(2peak) (+19%, P < 0.01), peak ventilation (+14%, P < 0.01), and peak oxygen pulse (+18%, P < 0.01). Analysis of variance revealed that most of the changes (71%) in .VO(2peak) could be explained by those in LBM and FEV1 (P = 0.001). CONCLUSION: GH treatment clearly improved exercise tolerance, presumably resulting from the combined effects of GH on the muscular, cardiovascular, and pulmonary capacity.

Adolescent↗