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Biomedical subjects

M Ravid

Publications and source records attributed to M Ravid.

At least 91 records · Page 5Linked to original sources
PubMed1988

The "ruler sign"--a semiquantitative physical sign of chronic obstructive pulmonary disease.

This report describes a simple and reproducible physical sign of chronic obstructive pulmonary disease--the "ruler sign." With the patient standing erect, a ruler is placed on the trapezius muscle and the clavicle at the midclavicular line. The ruler forms an angle with the horizontal line. At the end of a normal expiration this angle was 36 degrees +/- 4 SD in healthy control subjects as compared with 15 degrees +/- 4 SD in patients with severe chronic obstructive pulmonary disease. A simple device is described that enables convenient measurement of this angle at the bedside.

Adult↗
PubMed1987

Treatment of adverse digitalis effects by hemoperfusion through columns with antidigoxin antibodies bound to agarose polyacrolein microsphere beads.

Ten patients with an array of moderate to severe adverse effects resulting from digitalis were effectively treated by hemoperfusion through small columns which contained antidigoxin antibodies bound to polyacrolein microspheres in agarose macrospheres (APAMB). The procedure was well tolerated. There was no detectable damage to formed blood elements and no changes in electrolytes, liver enzymes, or other related biochemical parameters. Despite some theoretic considerations to the contrary, the removal of a relatively small load of digoxin resulted in amelioration of the clinical symptoms and ECG abnormalities associated with digitalis. No rebound phenomena of intoxication or posthemoperfusion increase in digoxin serum levels were noted over the subsequent 5 to 6 days. A further increase in the capacity of the columns may render this method a safe and convenient emergency procedure for patients with digitalis toxicity.

Acrolein↗
PubMed1987

Spectral analysis of heart rate fluctuations. A non-invasive, sensitive method for the early diagnosis of autonomic neuropathy in diabetes mellitus.

Early detection and a quantitative evaluation of the degree of diabetic autonomic neuropathy were performed in 23 diabetic patients and 22 controls by computerized spectral analysis of beat-to-beat R-R interval variations on a continuous electrocardiogram. Simultaneous recording of cardiac and respiratory activity, R-wave detection by a fast peak detection algorithm and spectrum computation by Fast Fourier transform enabled the study of the power spectrum of heart rate fluctuations. The power of fluctuations at different frequencies is the result of sympathetic and vagal input into the sinoatrial node: this input is derived from vasomotor, baroreceptor and respiratory control loops. A marked reduction in the power of heart rate (HR) fluctuations, at all frequencies, was found in the diabetic patients as compared to controls. This indicates a depression of both parasympathetic and sympathetic activity. The difference was especially pronounced in subjects below age 65. The lowest activity was found in diabetics with concomitant peripheral neuropathy. The method described here is simple, objective, quantitative and very sensitive. It may facilitate the screening of diabetic patients for autonomic neuropathy and enable a convenient quantitative follow-up.

Adult↗
PubMed1987

Spectral analysis of fluctuations in heart rate: an objective evaluation of autonomic nervous control in chronic renal failure.

A quantitative, noninvasive method of assessing autonomic control, based on the spectral analysis of beat-to-beat fluctuations in heart rate (HR), was applied to patients with chronic renal failure (RF). Since the power spectrum of HR fluctuations measures the dynamic nervous control of HR, it can be used to quantitate a normal control system as opposed to a disturbed or depressed system. Indeed, in RF patients, a strong reduction in the HR power spectrum was observed in all frequency ranges, both sympathetically and parasympathetically mediated. A similar depression in autonomic control was demonstrated in patients on hemodialysis or peritoneal dialysis. RF patients not yet undergoing dialysis show a lesser degree of depression. Spectral analysis of HR fluctuations in RF patients makes it possible to quantitate autonomic dysfunction and to reliably measure its development as a function of time, and requires only a 10-min standard electrocardiogram recording.

Adult↗
PubMed1987

Atenolol vs. amiloride-hydrochlorothiazide in the treatment of mild to moderate hypertension: a double-blind, crossover, placebo-controlled study.

The antihypertensive effect of atenolol 100 mg was compared to that of amiloride HCl 5 mg + hydrochlorothiazide 50 mg (AHCZ) in a double-blind, crossover, placebo-controlled study of 128 patients. Both drugs were given once daily. Atenolol produced a significant decline in lying, standing, and postexercise blood pressure and pulse rate values. The corresponding values on AHCZ were not significantly different from placebo. Both the beta-blocking agent and the thiazide diuretic with amiloride were relatively well tolerated. More than half of all adverse effects were nonspecific and also observed in patients on placebo. In the population studied, atenolol proved to be a superior antihypertensive agent to AHCZ.

Adult↗
PubMed1987

Digitalis hemoperfusion: increase of column binding capacity by pretreatment with ouabain.

Extracorporeal hemoperfusion through polyacrolein microsphere beads (APAMB) attached to antidigoxin antibodies is an effective treatment of digitalis intoxication. In order to increase the binding capacity of the APAMB columns the active sites of the antidigoxin antibodies were protected by ouabain during the binding to the microbeads. This brought about an 11-18 percent increase in digoxin binding capacity of the columns. It was also found that binding capacity does not increase with the rise of antibody concentration beyond a certain limit. Protection of antibody binding sites and determination of optimal concentration are, therefore necessary steps during preparation of antibody based hemoperfusion columns.

Acrolein↗
PubMed1986

Persistant hypokalemia due to bilateral fibromuscular dysplasia of the renal arteries.

Bilateral fibromuscular dysplasia of the renal arteries was the underlying pathology in a 51-year-old woman with severe hypokalemia and borderline hypertension. Very high renin levels were found in both renal veins. The secondary hyperaldosteronism was most probably responsible for the persistant hypokalemia in this patient.

Arterial Occlusive Diseases↗