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Biomedical subjects

H Deutsch

Publications and source records attributed to H Deutsch.

34 records · Page 2Linked to original sources
PubMed1982

[Continuous registration of micropotentials of the human heart. Initial experiences with a new high resolution ECG amplifier system].

A new ECG-amplifier system for recording cardiac microvolt potentials from the body surface is described. The improvement in signal-to-noise ratio was achieved by using specially designed suction electrodes, which were isolated from each other; by applying parallel signal averaging from four electrode pairs via four low-noise amplifiers; and by conducting the registration in Faraday cage. in 14 normal subjects, 12 patients with coronary heart disease and one patient with surgically corrected ventricular septal defect and pulmonary stenosis, pre-P-potentials (possible sinus node activity), His bundle potentials and ventricular late potentials were recorded with differing degrees of success. Variations of the time intervals to the preceding QRS complex were observed within the S-T segment in six of nine patients with demonstrable ventricular late ventricular late potentials. The advantage of such continuously recording ECG system lies in the highly accurate registration of cardiac micropotentials, particularly with ventricular late potentials that are changing in time, whereas the signal-averaging technique does not provide such possibilities.

Adolescent↗
PubMed1980

Intracerebroventricular osmosensitivity in the Pekin Duck. Properties and functions in salt and water balance.

Pekin ducks were implanted with devices allowing intracerebroventricular (i.c.v.) microinfusions at rates of 0.1--0.4 mul/min during 15 min in the conscious animals. When hydrated by intragastric infusion of 1 ml/min tap water, i.c.v. infusion of hypertonic NaCl solutions reduced urine flow and increased osmolality, presumably due to increased ADH release. Osmotically equivalent Li+ salts (Cl-, Br-, So24-) caused a slightly prolonged antidiuresis, while Ca2+ and Mg2+ salts caused a more protracted antidiuresis. Urea solution osmotically equivalent to 4.8% NaCl had no effect on diuresis, while osmotically equivalent mannitol solution slightly enhanced diuresis. Angiotensin II (0.5--2.5 pmol in 15 min) and Carbachol (3.0 pmol in 15 min) infused in 0.9% saline caused antidiuresis. The results suggest that the central control of ADH release in birds is similarly organized as in mammals, with receptive elements reacting to ionic rather than osmotic changes and with Na+ as the naturally involved cation. In ducks with their salt glands activated by i.v. infusion of 800 mosmol NaCl/kg H2O at 0.2 ml/min, salt gland secretion was not augmented by i.c.v. microinfusion of hypertonic NaCl but inhibited by i.c.v. infusion of osmotically equivalent mannitol solution. The supraorbital salt glands, when activated appear to be little stimulated further by a rise but may be inhibited by a fall of i.c.v. Na+ concentration.

Angiotensin II↗
PubMed1980

Serum arginine-vasotocin (AVT) and afferent and central control of osmoregulation in conscious Pekin ducks.

In conscious Pekin ducks adapted either to fresh water or to hypertonic saline (1.9%) as drinking fluid, urinary excretion, salt gland secretion and the serum concentration of radioimmunoassayable arginine-vasotocin (AVT) were examined with regard to their afferent and central control. The experiments were carried out under conditions of water diuresis, osmotic diuresis or supraorbital salt gland secretion, which were induced by continuous infusions of appropriate solutions. Temporary bilateral vagus blockade caused rises in AVT serum concentration accompanied by antidiuresis in hydrated ducks and by inhibition of salt gland secretion in salt-stressed ducks. Rostral brainstem cooling caused decreases of AVT serum concentration and water diuresis in ducks under osmotic diuresis and reduction of AVT serum concentration and inhibition of salt gland secretion in salt-stressed ducks. Cerebral osmotic stimulation in hydrated ducks by intracarotid injection or by intracerebroventricular microinfusion of hypertonic NaCl solutions caused antidiuretic reactions associated with rises of AVT serum concentration.

Animals↗
PubMed1975

Hormonal activity of testes in aged rats with leydig cell hyperplasia: histochemical investigation of some hydroxysteroid dehydrogenases.

The following enzymes were employed in order to investigate the hormonal activity of the testes in aged rats: 3-beta hydroxysteroid-DH, 11-beta-hydroxysteroid-DH, and 17-beta-hydroxysteroid-DH. Our investigations show that in the non-altered testis of the aged rat the same enzyme activities can be observed as in young and sexually mature animals. A proliferation of the Leydig cells (L.c.), occurring in the aging rat, brings about an increased activity of the above-mentioned steroid-DHs. An augmented production of testosterone is quite probable.

Aging↗
PubMedDate not supplied

Propentofylline in adult-onset cognitive disorders: double-blind, placebo-controlled, clinical, psychometric and brain mapping studies.

In a double-blind, placebo-controlled parallel group trial, the therapeutic efficacy and central effects of propentofylline (HWA 285) - a xanthine derivative with neuroprotective, metabolic, hemorheologic and antithrombotic action - were studied in 190 elderly outpatients with mild to moderate chronic cognitive disturbances (mild dementia, DSM-III-R). They received after a 2-week run-in period (placebo) for 12 weeks either 3 x 300 mg propentofylline or 3 x 1 tablet placebo (given at least 1 h before meals). The verum group (n = 96, age 68 +/- 9) was comparable to the placebo group (n = 94, age 69 +/- 8) in regard to age, height, smoking, consumption of stimulating alcoholic drinks, family and living status. Clinical evaluation by the Gottfries-Brane-Steen (GBS) scale demonstrated a significant superiority of propentofylline over placebo in the total score and the four GBS factors (motor, intellectual, emotional functions and other symptoms) as well as in the clinical global impression and Mini-Mental State. Psychometric measures showed slight and significant improvement in both groups but no intergroup differences. EEG brain mapping was carried out before and after 12 weeks' treatment in the Viennese subsample involving 24 propentofylline and 24 placebo patients. Propentofylline-treated patients exhibited, as compared with placebo-treated ones, a trend towards augmentation of total power, furthermore an increase in relative delta and beta and a decrease in alpha power, an acceleration of the dominant frequency as well as a slowing of the centroid of the combined delta/theta band. The total centroid tended towards acceleration, while the centroid deviation increased significantly. These alterations reflect vigilance changes of the dissociative type and differ from those of the classical nootropics. Clinical and psychometric evaluations demonstrated changes in the same direction as in the total sample, but interdrug differences were not significant. Thus, EEG brain mapping seems to be more sensitive in objectivating central drug effects.

Aged↗