Biomedical subjects
Publications and source records attributed to M Lehmann.
A 69-year old patient with high-grade malignant lymphoma experienced severe orthostatic hypotension during vincristine therapy. The symptoms disappeared when vincristine treatment was discontinued. The mechanism of the orthostatic hypotension is discussed.
The effects of alternating cycle lengths (bigeminal rhythm) on His-Purkinje system refractoriness were studied in 14 patients using His bundle and right bundle recordings. Programmed atrial stimulation at constant cycle length (method I) was scanned using the atrial extrastimulus technique (A2) and compared with an atrial cycle length of identical duration coupled to A2 on alternate beats (method II). The results showed that (a) despite shorter cycle length of the His-Purkinje system with method II due to effect of A2 on atrioventricular nodal conduction (699 +/- 90 vs. 743 +/- 87 ms, P less than 0.001), the relative refractory period of the His-Purkinje system was always longer with method II (463 +/- 52 vs. 440 +/- 43 ms, P less than 0.001). A similar increase also occurred in effective refractory period of the His-Purkinje system; (b) while functional right bundle branch block occurred in eight patients and functional left bundle branch block in two patients with method I, functional right bundle branch block occurred in all 14 patients and left bundle branch block in seven patients with method II; (c) in two patients where both functional right and left bundle branch block occurred with method I this never was manifest at identical degree of abbreviation of His-Purkinje system cycle length but was manifest at identical abbreviation in each of seven patients with method II; (d) site of conduction delay and/or block during functional right bundle branch block was always proximal, i.e., between the His bundle and right bundle recordings with both methods. During method II this resulted in shortening of the subsequent right bundle cycle length relative to the subsequent His bundle (and of necessity left bundle) cycle length. The finding of increased His-Purkinje system refractoriness despite shorter preceding cycle length of the His-Purkinje system during atrial bigeminy has never been previously described and suggests that classical concepts of His-Purkinje system behavior may require revision in this setting. Secondly, during atrial bigeminy the occurrence of alternating functional bundle branch block cannot be accounted for solely by the degree of abbreviation of His-Purkinje system cycle length, but may be explained by a relative shortening of the next ipsilateral bundle branch cycle length in the bundle manifesting block.
90 children of age between 1 and 10 years who were scheduled for adenotomy were randomized into 3 premedication-groups. Group 1 received no premedication, group 2 chlorprothixene 1 mg/kg i.m. and group 3 chlorprothixene 2 mg/kg orally. Prior to induction of anaesthesia 63.3% of the unpremedicated children were anxious or crying, in contrast to 23.3% of the children given oral or i.m. premedication. With respect to the reaction on venepuncture with a Butterfly G 23, there was no significant difference between the groups. The volume of gastric acid (median values) was 0.056 ml/kg in group 1, 0.063 ml/kg in group 2, and 0.068 ml/kg in group 3, with a pH of 2.0, 1.5 and 2.0 respectively. One hour after operation 44.8% of the children in group 1, 92.6% in group 2 and 84.6% in group 3 were calm or sleeping. Premedication definitively improves the pre- and postoperative management of children. We now recommend oral chlorprothixene for the premedication of children because the effect of this oral premedication is equivalent to i.m. application, and the oral route has no influence on the quantity or acidity of gastric contents.
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Twelve healthy control subjects, 9 cardiac patients with normal central hemodynamics, 9 patients with impaired left-ventricular contractility during exercise, and 10 patients with impaired contractility and coronary insufficiency (anginal pain and ST-segment depression of ECG) were investigated. Central hemodynamic values (Swan-Ganz catheter) as well as free plasma catecholamines noradrenaline and adrenaline were simultaneously determined at rest and during incremental exercise. At rest, no significant differences were observed between all groups. The cardiac patients with normal central hemodynamics also did not show any significant differences in their plasma catecholamine responses during exercise as compared with healthy control subjects. Patients with impaired left-ventricular contractility, indicated by a significantly increased pulmonary capillary wedge pressure, as reference value of increased left ventricular end-diastolic pressure, both with negative and positive indicators of coronary insufficiency during exercise, showed significantly higher noradrenaline levels at identical work loads than control subjects. However, adrenaline responses were only significantly higher in patients with positive indicators of coronary insufficiency during exercise. The noradrenergic responses may be triggered by a borderline reduction of cardiac output as well as by increased pressures in the low-pressure system. The over-proportional adrenergic responses may be an indicator of precordial anginal pain and anxiety. This reaction is seen to be significant for a further increase in myocardial oxygen demands and anginal pain.
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18 male post-infarction patients (56 +/- 9 years) were investigated before and after 1 year of controlled physical therapy. Results were compared with those observed in 7 healthy male control subjects (47 +/- 6 years). Left-ventricular impairment of the investigated patients corresponded haemodynamically to stages I and II of the Roskamm-Reindell classification, based on a Swan-Ganz catheter. The influence of physical therapy on plasma catecholamine levels was evaluated; free plasma catecholamines are seen as reference indicators of sympathetic activity. Cycling performance capacity (supine position) of the patients increased from 101 +/- 25 watt to 131 +/- 24 watt. Before and after physical therapy, maximal heart rate responses were similar (121 +/- 17 as compared with 119 +/- 16 min-1). After physical therapy, maximal noradrenaline responses were 16% lower, adrenaline responses down by 25%, and mean arterial blood pressure was 14 mm Hg lower. At identical work-load (50 watt level), reductions after physical therapy amounted to 25% (noradrenaline), 41% (adrenaline), 16% (heart rate), and 21 mm Hg (mean arterial blood pressure).
Blood pressure was recorded at rest and during exercise (n = 577) in 810 male sportsmen. Larger subgroups included 125 cyclists, 98 long-distance runners, 90 cross-country skiers, 108 players of various ball games, 25 weight-lifters, and 29 swimmers. At rest, hypertension was observed in 3.8% and borderline hypertension in 7.8% of the sportsmen investigated. When blood pressure responses during exercise were also included, values were increased by 28% to 4.9% (hypertension) and by 26% to 9.8% (borderline hypertension). In the sportsmen investigated, the age range 14-29 years was overrepresented. The age-corrected prevalence was 5.4% (hypertension) and 11.1% (borderline hypertension) at rest. The prevalence of increased blood pressure in sportsmen was about half of the prevalence expected for the total population (p less than 0.05). The low incidence of hypertension in sportsmen may be due to physical training as well as to genetic factors. Increased blood pressure was significantly more frequent in swimmers and weight-lifters than in the other investigated subgroups. In these two sports, unfavorable training-specific factors may compensate for the possible beneficial effects of physical training.
6 sports students (VO2 max. 54.0 +/- 2.6 ml/kg . min) and 6 marathoners (VO2 max. 65.7 +/- 2.0 ml/kg . min) performed graded treadmill tests. Free plasma catecholamines (noradrenaline and adrenaline), heart rate, lactate were assessed at rest and during exercise. The behaviour of beta-adrenergic receptors of polymorphonuclear leukocytes was estimated additionally before the treadmill test. The maximum running velocity was 14.6 +/- 0.8 km/h (sports students) and 17.3 +/- 0.6 km/h (marathoners). Noradrenaline was approximately 46% (v = 12 km/h) to 67% (v = 14 km/h) lower in the group of marathoners than in sports students; adrenaline showed no or smaller differences between both groups. No significant differences in the plasma catecholamine behaviour occurred between the groups at rest and during maximum exercise. Specific binding of 3H-Dihydroalprenolol to intact cells was higher in the marathoners than in sports students (p greater than 0.01). Scatchard analysis revealed a maximum binding of 21.1 fmol/10(7) cells (sports students) and 35.3 fmol/10(7) cells (marathoners), which indicated approximately 1,300 (sports students) and 2,150 binding sites cell (marathoners). Inverse correlations between noradrenaline (r = -0.63), VO2max. (r = -0.79) and the specific binding of 3H-DHA were observed. The reduction of plasma catecholamines (approximately 46-67%) and the increase in specific binding sites (approximately 67%) were in the same range.(ABSTRACT TRUNCATED AT 250 WORDS)
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The effects of the chelating agents CaNa2-ethylenediaminetetraacetate (EDTA), CaNa3-diethylenetriaminepentaacetate (DTPA), 2,3-dimercaptosuccinic acid (DMSA), 2,3-dimercaptopropanol (BAL), and 2,3-dimercaptopropane-1-sulfonate (DMPS) and of the lipophilic chelating agents Puchel, Puchel-bisamidocysteineethyl ester (Puch-D), and EDTA-bis-amidocysteineethyl ester (EDTA-D) on the distribution of iv injected Cd were studied in male Sprague-Dawley rats. The chelating agents were injected iv as single doses given 10 sec, 1 hr, or 3 hr after 3 mumol/kg Cd + 115mCd. When the chelating agents were injected within 10 sec after the metal, all agents reduced the total body cadmium burden by varying extents ranging from 3% of that in untreated control rats after 0.01 mmol BAL/kg to 94% following 0.1 mmol DTPA/kg. When given 1 hr after Cd injection, the efficacy of all the agents tested was markedly reduced or abolished; at this time only Puchel and Puch-D provoked significant reductions in the body burden of Cd by 21 and 32%, respectively. When treatment was delayed until 3 hr after Cd injection, only Puch-D was able to reduce the body and liver burden of the metal by 14 and 9%, respectively. Combined treatment with Puchel + DTPA, BAL + DTPA, or BAL + DMPS did not enhance Cd removal to an extent greater than that expected from the equivalent dose of the more effective agent of that pair alone. Repeated administration of DTPA, 20 X 0.1 mmol/kg, during 4 weeks by ip or po administration of the same dose in the drinking water over 4 weeks, was no no more effective than the first dose of the chelating agent alone. Gel chromatographic studies of the distribution of Cd among the proteins of the liver cytosol in treated and untreated animals indicate that neither DTPA nor Puchel was able to release Cd from the metallothionein complex.
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Free urine adrenaline, noradrenaline, (additional free plasma catecholamines in the physicians), and blood lactate were determined in 11 ambulance men and 5 physicians to assess stress during medical service. Stress was evaluated employing a stress index, based on difficulties in driving, traffic, severity of injuries or illness. Emergency cases with seriously injured subjects or reanimation were judged to have a 4-fold higher stress index than routine cases where strong physiological or psychological stress was absent. Urine catecholamines and stress indices were estimated in 3-h intervals. The calculations were based on the stress induced catecholamine concentrations minus the basal excretion during the same 3-h interval. Urine adrenaline and noradrenaline in ambulance men and physicians correlated directly with the stress index, as well as the plasma catecholamines of the physicians. Lactate levels showed similar behaviour and a descriptive direct correlation with the plasma catecholamines. Urine adrenaline increased more--dependent on the stress index--than urine noradrenaline. This over-proportional adrenaline response may be an indicator for the additional psychological stress in emergency cases. Therefore physicians showed--based on the same stress index--a tendency to higher urine adrenaline excretion and blood lactate levels than the ambulance men, which might be the consequence of the overall responsibility of the physicians. Because of the observed catecholamine responses during medical service, coronary insufficiency or hypertension might be contra-indications for participation in the medical service; regular clinical investigations including ergometric tests are advisable.
Nine healthy subjects performed 2 different graded bicycle ergometric tests. The 1st test started with 50 watt and was increased 50 watt after 3 min till exhaustion as a model of a metabolic and cardiac exhaustion. The 2nd test started with 100 watt and was increased 50 watt after 15 min till exhaustion as a model of a peripheral-muscular exhaustion. The behaviour of plasma catecholamines, lactate and glucose levels, heart rate and oxygen intake was examined. The results were as following: Performance ability 305 (test 1) and 233 watt (test 2; mean values), work time 17.5 min (1) and 51 min (2), heart rate 185 min-1 (1) and 175 min-1 (2), noradrenaline 30.7 nmol/l (1) and 11.0 nmol/l (2), adrenaline 6.9 nmol/l (1) and 2 nmol/l (2), lactate 9.2 (1) and 6.6 mmol/l (2), glucose 5.6 mmol/l (1) and 4.7 mmol/l (2). During highly intensive dynamic exercise (test 1), three times higher catecholamine and 50% higher lactate responses were observed, than during peripheral-muscular limited endurance exercise (test 2). Above an exercise level of more than 30% VO2 max., nor- and adrenaline increased significantly. Below 50-70% VO2 max. steady-state-behaviour occurred. Above this range unsteady-state-behaviour of plasma catecholamines was observed. Dopamine did not show any significant time and intensity dependent increase. Noradrenaline and adrenaline followed the same initial 1st order elimination kinetic.
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Correlations between distance running performance and laboratory testing were examined in 11 marathoners of similar fitness (VO2max 66.4 +/- 1.7 ml/kg X min). They performed a graded treadmill test and a subsequent 30 km cross-country run. Heart rate, oxygen intake, blood lactate, and plasma catecholamines were measured during the treadmill test. Lactate equivalent, individual lactate threshold, 4 mmol lactate threshold, submaximum (16 km/h running velocity) lactate behavior, submaximum catecholamine responses, submaximum lactate-catecholamine product, measured VO2max, and extrapolated VO2max were examined for their adequacy in the evaluation of distance running capacity. Race times and free urine catecholamines were estimated in the field experiment. Direct correlations were found between race times and minimum lactate equivalent (r = 0.69), submaximum lactate levels (r = 0.52), submaximum catecholamine responses (r = 0.69), submaximum lactate-catecholamine product (r = 0.79), respectively. Inverse correlations were observed between race times and oxygen intake at individual lactate threshold (r = -0.68), 4 mmol lactate threshold (r = -0.76), measured VO2max (r = -0.71), and extrapolated VO2max (r = -0.63). Further correlations were found between submaximum noradrenaline and lactate behavior (r = 0.53), as well as between noradrenaline and adrenaline responses (r = 0.72). No significant correlation was observed between relative heart volumes or catecholamine excretion and race times.