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Biomedical subjects

M Runge

Publications and source records attributed to M Runge.

At least 109 records · Page 6Linked to original sources

Changes in heart rate by verapamil during carotid sinus stimulation in patients with hyperparathyroidism, pre- and postoperatively.

It has been investigated whether calcium- and verapamil-dependent sensitivities of carotis baroreceptors also exist in man. To answer this question, we pre- and postoperatively measured changes in heart rate during carotid sinus stimulation before and after intravenous administration of 5 mg verapamil in 23 patients with primary hyperparathyroidism. Findings during hypercalcemia were as expected: a more pronounced reduction of heart rate at comparatively low calcium levels. During normocalcemia, we found an opposite effect: a more pronounced reduction at relatively high calcium levels, which was statistically significant. This fact could be explained according to our interpretation. In previous reports, local effects on baroreceptors were examined, whereas we measured the combined effect of several calcium actions. As expected, verapamil attenuated the decrease in heart rate which, however, was not statistically significant.

Calcium↗

[The influence of frequency and blockade of the autonomic nervous system on the functional behaviour of the human conduction system. Part B: Refractory periods (author's transl)].

32 patients were studied by His-bundle-electrocardiogram and programmed atrial stimulation to examine to which extent frequency and autonomic tone participate in influencing the effective (ERP) and functional (FRP) refractory periods of the atrium and AV-node. The measurements were performed during three electrically induced atrial frequencies before and after intravenous injection of 1 mg Atropine (15 patients) and 0.4 mg Visken (17 patients). For the atrium, frequency dominates the blockade of both components of the autonomic nervous system in influencing both refractory periods. Increase in frequency shortens both ERP and FRP of the atriu. The blockade of parasympathicus and sympathicus does not significantly influence the changes in atrial ERP and FRP induced by atrial pacing. The AV-node responses most sensitive to both pacing induced cycle length shortening and blockade of the autonomic tone. Cycle length shortening prolongs the nodal ERP. the FRP is either shortened or prolonged. Blockade of the parasympathicus shortens both nodal ERP and FRP. Blockade of the sympathicus lengthens both parameters. This behaviour of both refractory periods in response to atrial pacing and blockade of the autonomic tone are discussed with respect to the "gate mechanism" in the conduction system. In the majority of patients blockade of the parasympathicus shifts the "gate" from the AV-node to the atrium. Blockade of the sympathicus has the opposite effect in some cases.

Adrenergic beta-Antagonists↗

[The adaptation of AV-nodal conduction time on gliding increase and decrease of atrial frequency before and after autonomic blockade (author's transl)].

In 19 patients with healthy AV-nodes the adaptation of the intranodal conduction time (A-H time) to gliding increase and decrease in atrial frequency and to the blockade of the autonomic nervous system was investigated using His bundle electrograms. The measurements were performed during right atrial stimulation with three frequencies, each with a duration of one minute, before and after blockade of the parasympathetic (8 pat.; 1 mg atropine i.v.) and the sympathetic (11 pat.; 0.4 mg Visken i.v.) nervous system. Gliding increase and decrease in atrial frequency results in a staircase pattern of A-H-adaptation in 18 of the patients. The height of the steps was identical in both phases of stimulation in each individual patient. One patient showed functional dissociation of intranodal conduction which was different during increase and decrease of atrial frequency. With parasympathetic blockade the staircase behavior of the A-H time basically remained unchanged with the exception of shorter A-H intervals resulting in lower steps. Atropine abolished the functional dissociation of intranodal conduction; thus the drug might prevent reentrytachycardias due to functional dissociation in the AV-node. Sympathetic blockade lengthens the intranodal conduction time; thus shifting the staircase pattern of the A-H time to higher levels. The results are discussed with respect to the electrophysiological characteristics of AV nodal cells as slow response fibers, and to the changes caused by atrial stimulation, acetylcholine and adrenaline.

Atrioventricular Node↗

[Influence of cycle length shortening, atropine and beta-receptor blockage on sinus node recovery time (SRT) in patients with healthy sinus node (author's transl)].

Sinus node recovery time (SRT) was measured in 30 patients with healthy sinus nodes to examine the influence of the increase in atrial frequency, atropine and beta-receptor blockade. The measurements were performed following pacing with 3 atrial frequencies before and after administration of 1 mg atropine i.v. (13 patients) and 0.4 mg prindolol (Visken) i.v. (17 patients). Total group; Increase of frequency alone caused prolongation of the SRT in 17 patients and shortening in 13 patients. Atropine group: Blockade of the parasympathicus alone induced a highly significant reduction in the SRT. Simultaneous increase in frequency and blockade of the parasympathicus led to greater SRT-shortening during low frequency than with high frequency. This interrelationship of frequency and blockade of the parasympathicus influencing the SRT is statistically significant. Visken-group: Blockade of the sympathicus causes a highly significant prolongation of the SRT. Simultaneous increase in frequency and blockade of the sympathicus led to greater SRT-prolongation during low frequency than with high frequency. This interrelationship of frequency and blockade of the sympathicus influencing the SRT has slight statistical significance. The results are discussed in respect to the electrophysiological influences of atrial cycle length shortening, acetylcholine and catecholamines on the sinus node, the perinodal atrial fibres and the atrial working myocardium.

Atropine↗

Use of serum PIVKA-II (DCP) determination for differentiation between benign and malignant liver diseases.

BACKGROUND: The concentration of Des-gamma-carboxy-prothrombin (DCP) or PIVKA-II has been described to be increased in patients with hepatocellular cancer, along with its elevation in vitamin K deficient states by warfarin or dicoumarol treatment. The aim of the study was to investigate its clinical value in HCC in comparison with alpha-fetoprotein. PATIENTS AND METHODS: Measurements were performed in duplicate in serum of 87 patients with benign (acute/chronic hepatitis B/C/autoimmune, liver cirrhosis B/C/alcoholic) and 154 patients with highly probable (CT, MRT imaging) or histologically proven HCC. Two commercial or research ELISA tests (1: Eitest MonoP-II, Eisai, Tokyo, Japan; 2: Asserachrom PIVKA-II, Stago, France) using murine monoclonal anti-PIVKA-II antibodies were used comparatively and compared with a laboratory-developed conventional AFP-RIA. RESULTS: By ROC analysis, a highly significant discrimination (p < 0.0001) was found at cutoffs of 0.09 AU/ml (Eisai) or 0.8 ng/ml (Stago) at a specificity of about 90% (Eisai: s = 78.6%, ppv = 0.92, npv = 0.70; Stago: s = 77.9%, ppv = 0.93, npv = 0.70) compared with the AFP-test at a cutoff of 45 ng/ml (sp = 91%, s = 58.4%, ppv = 0.92, npv = 0.55). A higher significant correlation was seen between both DCP tests in malignant (rS = 0.89, p < 0.0001) than benign groups (rS = 0.41, p < 0.001) and a lower correlation between the AFP and Eisai (rS = 0.27/0.36, p < 0.01) and Stago test for the malignant group (0.16; p < 0.05). CONCLUSION: DCP determination in serum/plasma adds significantly in the discrimination between benign and malignant liver diseases.

Adult↗

Determinants of musculoskeletal frailty and the risk of falls in old age.

Neuromuscular parameters that describe locomotion are indispensable variables for the diagnosis and treatment of frailty, fall risk and osteoporosis. A scientifically-based standardized locomotor assessment should be an essential part of medical examinations in research and clinical practice. There has been no previous consensus regarding which test procedures should be included in a locomotor assessment. The goal of this article is to provide a rationale for the selection of appropriate locomotor tests in a comprehensive locomotor assessment for elderly patients. We propose that a locomotor assessment should comprise the parameters that have been proven predictive for both falls and impending disability. The parameters should be measured in the standard units of physics. Therefore, we propose the following tests for a standardized locomotor assessment: (1) Self-selected gait velocity as the single best measure of general locomotor status and a good predictor of age-related adverse events; (2) Chair rise test (timed 5 chair rises) which measures power on vertical movement and the hip surrounding muscles as the most important neuromuscular risk factor for falls and fall-related fractures; (3) Tandem standing and tandem walking to measure postural capacity (balance) to the side; (4) Timed up and go test as a global screening procedure; (5) Clinical gait analysis with special focus on regularity; and (6) At least on a research level, movement must be measured referring to the terms of physics by mechanography. Mechanography (Leonardo force plate system, Novotec Pforzheim, Germany) records the time course of ground reaction forces, velocity of the vertical movements of the center of mass and power during unrestricted physiological movements. In the mechanogram the eccentric and concentric phases of movements can be differentiated and the storage of energy in the elastic elements of the body can be examined. The kinetics of human movement is explained by mechanograms of a two-legged jump. The ground reaction forces resulting from a jump down from a height of 0,46 m are demonstrated as a performance that is representative for human coordination. One goal of this text is to underline the insights that arise if the rules of physics are applied to human movement. A deeper understanding enables us to create more effective treatments for disorders of the muscle-bone unit. Bringing physics and cybernetics into the field of osteoporosis is a great heritage of Harold Frost.

Accidental Falls↗