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Biomedical subjects

F Mahler

Publications and source records attributed to F Mahler.

At least 145 records · Page 8Linked to original sources
PubMed1981

[Drug therapy of peripheral arterial occlusive disease].

Vasoactive drugs may be effective via four mechanisms of action: vasodilatation, increase of driving pressure, improvement of blood fluidity and amelioration of the metabolism of the perfused tissue. Vasodilators in severe stages of peripheral arterial occlusive disease may involve hazards due to redistribution phenomena. The newer vasoactive drugs supposedly act by improving rheology and/or metabolism. Although a number of trials suggest clinical improvement of claudication, the primary use of vasoactive drugs cannot be recommended. In clinical practice vasoactive drugs should be discontinued when no effect can be verified in the individual treated. In pain at rest and/or gangrene, all the deobliterating procedures must be exhausted before drug therapy is given.

Arterial Occlusive Diseases↗
PubMed1980

[Effect of different stress tests on ankle blood pressure in patients with arterial circulatory disorders].

Under normal conditions systolic ankle blood pressure exceeds that at the arm at rest and one minute after exercise, thus rendering the arm-ankle difference negative. In the presence of arterial obstructions this difference is positive at rest or becomes positive after exercise. To determine its value and applicability in a given case, several ways of stress testing have been compared. On average the increase in pressure difference produced by 100 m exercise on a treadmill ergometer over pressure difference at rest followed the equation: delta P100m = 1.53 delta PR + 24.8 mm Hg, r = 0.92. The increase after maximum or 200 m exercise and that after standardized tip-toeing was comparable. Postocclusive reactive hyperemia produced a smaller but still significant increase. When patients were compared after 100 m treadmill exercise, those with stenoses exhibited a greater increase than those with complete occlusions, even though the resting pressure difference was equal.

Ankle↗
PubMed1980

[New aspects in the treatment of renal artery stenosis].

Demonstration of new methods in the treatment of renal artery stenosis appears justified if one takes into account that the overall results of conventional surgical treatment are less than satisfactory. Reimplantation of the renal artery, renal auto-transplantation and transluminal dilatation are examples of new approaches. The early results of a series of transluminal dilatations are encouraging and are presented here for consideration.

Dilatation↗
PubMed1979

[Dynamic measurement of blood pressure in human nailfold capillaries].

Dynamic blood pressure was measured in 33 human finger nailfold capillaries after direct cannulation with glass micropipettes by means of a resistance servonulling pressure measuring method. ECG, finger pulsations and respiratory thorax excursions were monitored simultaneously. All recordings exhibited pulsatile oscillations related to the cardiac rhythm. These oscillations resembled the wave forms of arterial pulsations with steep upstroke and dicrotic notch when the pressure amplitudes were above 10 mmHg. There was no apparent dependence on respiration. In 12 instances pressure fluctuations with frequencies ranging from 0.2 down to 0.07 Hz were observed in both the arteriolar and venular limb. Blood pressure in human skin capillaries is pulsatile and subject to remarkable fluctuations in the arteriolar as well as in the venular limb, systolic pressure values ranging from 14 to 71 mmHg and from 11 to 52 mmHg respectively.

Blood Pressure Determination↗
PubMed1979

Diffusion, pericapillary distribution and clearance of Na-fluorescein in the human nailfold.

An intravital fluorescence videomicroscopy technique is described in an attempt to develop non-invasive methods for the study of transcapillary exchange in human physiology and clinical medicine. The apparatus used consists of a Ploemopak incident light fluorescence microscope and a low light level television camera with linear output. After intravenous bolus injection of Na-fluorescein in 12 healthy subjects the movement of the dye particles in the nailfold was observed and stored on video-tape. Immediately after arrival the dye leaks into a halo-like section and later into the more remote parts of the pericapillary space. By moving a densitometric window on an axis transversal to the capillary loop (single frames of the tape), characteristic patterns of fluorescent light intensity distribution were obtained at different time intervals. At the edge to the halo the high pericapillary light intensity decreases abruptly moving further away from the capillary (mean: 10.0 micron) for 20 min and more in each individual indicating the presence of a diffusion barrier at this location between halo and more remote areas. Clearance of the dye is much slower than transcapillary diffusion and lasts approximately 2 h.

Adult↗
PubMed1979

Blood pressure fluctuations in human nailfold capillaries.

Dynamic blood pressure was measured in 33 human finger nailfold capillaries after direct cannulation with glass micropipettes by means of a resistance servo-nulling pressure measuring method. ECG, finger pulsations, and respiratory thorax excursions were monitored simultaneously. All recordings exhibited pulsatile oscillations related to the cardiac rhythm. These oscillations resembled the wave forms of arterial pulsations with steep upstroke and dicrotic notch when the pressure amplitudes were above 10 mmHg. There was no apparent dependence on respiration. In 12 instances, pressure fluctuations with frequencies ranging from 0.2 down to 0.07 Hz were observed in both the arteriolar and venular limb. Blood pressure in human skin capillaries is pulsatile and subject to remarkable fluctuations in the arteriolar as well as in the venular limb, systolic pressure values ranging from 14 to 71 mmHg and from 11 to 52 mmHg, respectively.

Adult↗
PubMed1978

[Indications for bandaging of the legs].

Study of the literature on the prevention of deep vein thrombosis shows the inefficacy of calf bandaging in the ambulation phase. Since thrombosis starts soon after or during operation, prophylactic measures are successful only if performed from the beginning of hospitalization. Orthostatic disturbances are not a general problem in the mobilization phase, as is shown in a study on 20 patients after myocardial infarction or heart surgery in whom leg compression did not influence circulatory regulation. In chronic venous or lymphatic insufficiency, however, compression therapy is of proven value. Such patients should be identified and treated. On the other hand, leg bandaging as a general preventive measure in the mobilization phase is no longer justified, but is indicated in individual patients with venous or orthostatic problems.

Bandages↗
PubMed1977

Pharmacologic and hemodynamic influences on the rate of isovolumic left ventricular relaxation in the normal conscious dog.

We studied the effects of acute pharmacologic and hemodynamic interventions on isovolumic left ventricular relaxation in 19 conscious dogs using micromanometer tip catheters. Isoproterenol (11 studies) augmented peak rate of rise of left ventricular pressure [(+) dP/dt] by 1,275+/-227 (SE) mm Hg/s (P < 0.001) and dP/dt at an isopressure point of 35 mm Hg during isovolumic relaxation [(-) dP/dt(35)] by 435+/-80 mm Hg/s (P < 0.001). Peak (-) dP/dt decreased by 467+/-89 mm Hg/s (P < 0.002). The time constant, T, derived from the logarithmic fall of pressure during isovolumic relaxation, shortened from 20+/-2.8 to 14.9+/-1.8 ms (P < 0.003). Calcium (11 studies) increased peak (+) dP/dt and (-) dP/dt(35) (both P < 0.0001); peak (-) dP/dt was unchanged. T shortened from 20.4+/-1.8 to 17.3+/-1.5 ms (P < 0.002). Volume (13 studies) did not affect either dP/dt or T. Phenylephrine (13 studies) augmented peak (-) dP/dt, but reduced (-) dP/dt(35) (both P < 0.01); T lengthened from 22.1+/-1.5 to 32.5+/-1.5 ms (P < 0.01). In 15 studies, rapid atrial pacing increased peak (+) dP/dt and (-) dP/dt(35) (both P < 0.01). In the first post-pacing beat, peak (-) dP/dt and (-) dP/dt(35) decreased (both P < 0.01), although peak (+) dP/dt increased further. T paralleled values of (-) dP/dt(35). In five dogs, beta adrenergic blockade had no significant effect on any variable after calcium, volume, or phenylephrine infusion or during or after atrial pacing when the pre-and post-propranolol states were compared. We conclude that positive inotropic interventions augment both left ventricular contraction and relaxation. The changes in isovolumic relaxation are independent of alterations in sympathetic tone produced by beta-adrenergic blockade. Peak (-) dP/dt may not be a valid measure of left ventricular relaxation rate during acute alterations in inotropic state or afterload.

Animals↗