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Biomedical subjects

U Freyschuss

Publications and source records attributed to U Freyschuss.

At least 55 records · Page 3Linked to original sources
PubMed1983

Effect of terbutaline on lung mechanics and morphology in the preterm rabbit neonate.

Lung morphology, surface properties of fetal pulmonary fluid, and lung mechanics during spontaneous breathing were studied in preterm newborn rabbits after antenatal administration of terbutaline (0.1 mg). The histological evaluation of lung sections revealed increased amounts of granular eosinophilic and sudanophilic material in the terminal airspaces. The amount of fetal pulmonary fluid was decreased in terbutaline-treated animals; the fetal pulmonary fluid also showed improved surface properties, evaluated by the pulsating bubble technique. Increased dynamic lung compliance without altered air-way resistance was found in terbutaline-treated animals during the first 30 min after onset of breathing. This report demonstrates that terbutaline has an initial beneficial influence on the preterm neonatal lung, probably due to release of preformed surfactant into the alveolar spaces and to dehydration of the lung.

Animals↗
PubMed1982

Effects of long-term bromocriptine treatment on catecholamine excretion and on circulatory adaptation to orthostasis and to exercise in patients with hyperprolactinemia.

Sympatho-adrenally regulated mechanisms of the circulatory system have been studied in seven patients with hyperprolactinemia in order to evaluate the effects of long-term (1-3 months) treatment with bromocriptine. Before treatment catecholamine excretion was within the normal range. Blood volume was low and there was a marked heart rate reaction to orthostasis. ECG showed no abnormalities. Blood pressure and ECG reaction during exercise were normal. The blood pressure heart rate response to handgrip was less marked than in healthy young men. During bromocriptine treatment, serum prolactin levels normalized in all but one patient. Total catecholamine excretion was lowered. Body weight diminished. Resting heart rate and blood pressure fell significantly. Blood volume per kg body weight remained unchanged as did the orthostatic heart rate increase. The circulatory response to handgrip was less marked than before therapy. It seems that long-term bromocriptine therapy provokes a cardiovascular pattern reflecting an inhibition of sympatho-adrenal activity.

Adenoma↗
PubMed1982

Ventilation-perfusion relationships in children.

Ventilation-perfusion relationships (Va/Q) were studied in nine lung-healthy children, 7-15 years old, in whom a diagnostic heart catheterization was performed. VA/Q was assessed by a multiple inert-gas elimination technique. In subjects above 10 years of age, single, narrow modes of ventilation and perfusion were seen centred upon a VA/Q ratio of one. In three of the four youngest children, 10 years old or less, additional; 'high' VA/Q regions were observed. Neither shunt, nor 'low' VA/Q regions were seen in any child. Arterial PO2 was above 12 kPa in all except one and no age dependence was observed.

Adolescent↗
PubMed1982

Circulatory adaptation in newborn infants of strictly controlled diabetic mothers.

Possible relations between neonatal circulatory function and maternal diabetic control were investigated in 22 infants of strictly controlled diabetic mothers during the first 2 days after birth. Eleven infants were delivered vaginally (V) and 11 infants by elective cesarean section (S). Maternal diabetes was more severe in the latter group. Half of the infants had one or more episodes of neonatal morbidity although none presented symptomatic hypoglycemia. Plasma glucose FFA and C-peptide were measured at birth and 3-6 hours later together with skinfold thickness; heart size was determined by X-ray at 24-28 hours; stroke volume and cardiac output were repeatedly determined by transthoracic impedance and ECG. C-peptide at birth was higher in group S than in V. C-peptide in both groups were neither related to glucose or FFA nor to birthweight or skinfold thickness. Infants with neonatal complications including cardiomegaly had the highest C-peptide values. Skinfold was positively correlated to maternal pregnancy glucose level, birthweight percentile and infant heart volume. Mean values for stroke volume and cardiac output were similar in both groups and not different from normal controls when related to body weight. Heart volume and stroke volume were significantly related. ECG abnormalities were seen in 6 infants who showed cardiomegaly on X-ray. We suggest that the present finding of an association between elevated C-peptide concentration at birth and the occurrence of neonatal complications including cardiomegaly and ECG abnormalities could be the consequence of functional hyperinsulinism and that the cardiomegaly is of adaptive type.

Blood Glucose↗
PubMed1982

Pulmonary function after lobectomy for congenital lobar emphysema and congenital cystic adenomatoid malformation. A follow-up study.

Eight patients with congenital lobar emphysema and eight with congenital cystic adenomatoid malformations were operated upon between 1970 and 1978. A lobectomy was performed in all cases. At follow-up after 3 to 11 years all of the patients without concomitant disease or malformations were subjectively well with a physical performance equal to those of their playmates. Lung function tests indicated lung volumes of about 90% of predicted normal values, indicating some compensatory growth of the remaining lung tissue. Functional impairment owing to loss of lung tissue or residual disease was ruled out by the existence of a normal working capacity and maintenance of the alveolar gas exchange during intense exercise.

Carbon Dioxide↗
PubMed1981

Digital pulse volume in the evaluation of haemodynamic effects of cardiac pacing.

Some artificially paced patients experience symptoms referrable to competition between spontaneous and pacemaker-induced heart activity. Haemodynamic studies are necessary to establish a relationship. Non-invasive techniques are desirable. Because of the considerable variations in haemodynamic variables from one beat to another it seems necessary to do beat-to-beat analysis. In the present study a comparison has been made between digital arterial pulse amplitude (DAPA) and central haemodynamic parameters in six patients at different pacing modes. A good correlation was found between DAPA and arterial pulse pressure (r = 0.83-0.99). The mean difference in cardiac output between atrio-ventricular pacing and ventricular pacing with atrial activation in early systole was 1.11 /min (P less than 0.01). A mean increase of 70% in DAPA was found at optimal PR-time as compared to simultaneous atrial and ventricular activation; wide individual variations were, however, seen. The results presented indicate that peripheral pulse volume registrations may be helpful in evaluating the consequences of atrial contractions for haemodynamic variables and to find those paced who may benefit from atrial or bifocal heart stimulation.

Aged↗
PubMed1981

Cardiovascular response to spinal anaesthesia in elderly men: effects of head-up tilt and dihydroergotamine administration.

In nine elderly (mean age 60, rang 42-74 years) cardiovascular pressures and cardiac output have been measured by catheterization of the pulmonary and brachial artery during spinal anaesthesia without and with dihydroergotamine (DHE) and during an added slight head-up (10-15 degrees). Spinal anaesthesia lowered arterial pressure and also stroke volume. After DHE arterial pressures as well as stroke volume were normalized. Tilting before spinal anaesthesia lowered stroke volume but arterial pressures were maintained. During spinal anaesthesia, tilting lowered arterial pressures as well as filling pressures of the heart. After administration of DHE during spinal anaesthesia the pressures were unaffected by tilting. It is concluded that in elderly men, unlike the young men previously studied, spinal anaesthesia decreases arterial blood pressures by a combination of reduced peripheral resistance and decreased stroke volume. The decreases in stroke volume and cardiac output were most pronounced in those patients with a reduced blood volume. DHE also prevents arterial pressure fall with head-up tilt during spinal anaesthesia.

Adult↗
PubMed1981

Effect of short-term CO2-breathing on the CO2 content and intracellular pH in skeletal muscle of man.

Subjects inhaled air with 8% CO2 for 10 min. Carbon dioxide tension in arterial blood increased rapidly from about 5 kPa to 7 kPa, whereas venous CO2 tension increased more slowly, reaching the arterial value at the end of the CO2-breathing period. Muscle content of total CO2 (HCO-3, H2CO3, solubilized CO2) did not change during CO2-breathing or the following 15 min of recovery. However, when CO2-breathing was combined with light bicycle exercise, total CO2 increased by 30%. This could be an effect of both increased local circulation and increased endogenous CO2 production in the muscle. It is concluded that 10 min CO2-breathing alone is insufficient to affect CO2 content and intracellular pH in resting skeletal muscle.

Acid-Base Equilibrium↗
PubMed1981

Circulatory effects in healthy young men of atrial pacing at rest and during isometric handgrip.

1. The influence of a fixed heart rate and cardiac output on the cardiovascular response to isometric handgrip at one third of maximal voluntary contraction has been studied by means of atrial pacing. 2. At rest, atrial pacing with a mean heart rate of 109 beats/min increased cardiac output and forearm blood flow while total systemic and forearm vascular resistance decreased. 3. During handgrip, total systemic resistance increased both with and without pacing. A slow lowering of forearm vascular resistance was noted in the former situation, no change in the latter. 4. It is concluded that atrial pacing per se increases cardiac output in healthy, young volunteers. Handgrip elicits a vasoconstriction on other vascular beds than the resting forearm.

Adult↗
PubMed1980

The effects of pharmacological treatment on pulmonary function in children with exercise-induced asthma.

The effects of two therapeutic regimens were investigated in eleven boys and eight girls (8--13 years) with a history of exercise-induced asthma (EIA), who reacted with subjective signs of EIA and a decrease in FEV1.0 exceeding 10% after an exercise test. A test program (TP) including complete spirometry, bicycle ergometer and treadmill exercise tests preceded and followed by dynamic spirometry at one and five min after exercise, was performed before and after each treatment period. In 12 patients with sporadic medication before the trials, continuous peroral treatment with a combination of a beta 2-stimulating drug and a xanthine derivative for three weeks did not significantly improve TP data. In 13 children (six from the above group) who were already on continuous treatment as above, addition of disodium cromoglycate (DSCG) inhalations for 3--4 weeks improved the response to acute administration of a beta-receptor stimulatory aerosol but did not influence EIA. Seven of the children continued their DSCG treatment for one year. Minor improvement of EIA provoked by cycling but not by treadmill was seen after this. The ventilatory effort in relation to working intensity was lowered. No significant differences were found between treadmill running and cycling in provoking asthma.

Adolescent↗
PubMed1980

Cardiovascular reflexes in short-term diabetics with normal physical working capacity.

The aim of the study was to elucidate whether disturbances of sympathetic and parasympathetic control of cardiac functions appear in short-term diabetics. For this purpose, cardiovascular reflexes [resting heart rate (HR), respiratory sinus arrhythmia, Valsalva manoeuvre, orthostatic test] and physical working capacity were investigated in fifteen maturity-onset diabetics (aged 40-60 years, duration of diabetes 1-9 years) and nineteen healthy volunteers. All diabetics had normal sensory tests, positive Achilles tendon jerks, and no signs of retinopathy or nephropathy. In the diabetics, HR at rest was increased (in the diabetics 80 +/- 12 vs 69 +/- 9 beats/min in the controls, P less than 0.01), the Valsalva ratio was decreased (P less than 0.01) and respiratory sinus arrhythmia decreased (P less than 0.05). In contrast, the physical working capacity was not altered. This study demonstrates impairment of cardiovascular reflexes in short-term diabetics, most likely due to neuropathy of the vagal nerves.

Adult↗
PubMed1980

Familial cardiomyopathy--a 15-year follow-up.

In 1961--1962 five families including 53 members with a familial form of cardiomyopathy (CMP) were examined. Fifteen years later a reinvestigation of the previously examined families was carried out using community registers; mortality as well as new family members were registered. Another 50 family members were thereby added. Three out of 6 young subjects who were diagnosed as having definite (2) or suspected (1) CMP at the initial examination died during the follow-up period. Four of the five families, totalling 39/41 members, were given a thorough noninvasive clinical examination including ECG, phonocardiogram exercise test, measurement of systolic time intervals and carotid arterial pulse curves, and echocardiography (Echo). A high number (17/39) of suspected or definite pathologic echocardiographic changes consistent with CMP was observed on reinvestigation. Eleven of these 17 were asymptomatic. Except for Echo, the non-invasive methods used in this study did not contribute to the diagnosis of CMP, but the non-Echo methods confirmed the Echo findings in those patients with symptoms of cardiac disease. The four reexamined families revealed a very heterogenous pattern of CMP, with both symmetric and asymmetric hypertrophy (ratio symmetric/asymmetric = 15 : 2). It may be questioned whether asymptomatic subjects with borderline changes, indicative of symmetric hypertrophy, will develop definite symmetric CMP or whether their symptoms constitute an early stage of asymmetric CMP. Echocardiographic findings may well fit with the theory of a dominant mode of inheritance.

Adolescent↗
PubMed1979

Serial measurements of thoracic impedance and cardiac output in healthy neonates after normal delivery and caesarean section.

Thoracic electrical impedance measurements were serially performed during the 1st, 2nd, 8th and up to the 32nd hour of life in two groups (V and S) of healthy infants. In group V, all 24 infants were delivered vaginally, in group S, all 24 infants were delivered by caesarean section for obstetrical reasons. Basal thoracic impedance (Zo), heart rate (HR), stroke volume (SV) and cardiac output (Q) were determined on each examination. In group V, Zo increased from 31.9 to 34.0 ohm between 2 hours and the last recording between 8 and 32 hours. SV decreased from 4.1 to 3.4 ml between 2 and 4 hours and was accompanied by a decrease of Q from 560 to 450 ml/min. Heart rate slowed from 129 to 115 beats/min between 2 hours and the last recording at greater than or equal to 8 hours. In group S, Zo increased from 32.2 to 35.9 ohm between 2 and 8 hours. Mean SV increased from 3.6 to 4.4 ml between 8 and 32 hours and heart rate slowed from 131 to 113 beats/min between 1 and 8 hours. No significant differences were observed between the groups. The accuracy of the impedance--SV and Q data cannot be validated. For the most part they compare favourably with values previously obtained by soluble gas methods. Serial changes may reflect not only decreasing shunts and/or increasing aeration but also changes in total fluid volume of the lungs, intra- or extravascular. The precision of the measurements is good since reproducibility of single SV and Q determinations is higher than with standard dilution techniques. The data obtained may serve as baseline values for comparison with data in infants of the same age with various anomalies.

Cardiac Output↗
PubMed1978

Exercise energy expenditure in extreme obesity: influence of ergometry type and weight loss.

Bicycle and treadmill exercise tests including oxygen uptake (VO2) and heart rate (HR) determination were carried out on a total of thirty patients with obesity, seventeen of whom were reinvestigated after weight loss. During both types of work VO2 for a given load was higher when compared to healthy controls. The increase of VO2 was more marked when cycling was performed in sitting position than in supine. The mechanical efficiency of sitting bicycle exercise averaged 17.8% and was negatively related to the percentage overweight; the slope of the VO2/load regression line was slightly less in comparison to the controls, while no such difference was found during treadmill walking. After weight reduction the VO2/load regression line was skifted downwards, the slopes being unchanged, thus the mechanical efficiency improved. This study not only confirms the observation of a low mechanical efficiency of obese subjects but also demonstrates that the change is quantitatively related to the overweight. The lowered efficiency was caused by body mechanical factors and there was no support for an abnormal muscular efficiency. Exercise tests should be combined with VO2 determination, if used to assess the circulatory capacity of obese subjects.

Adult↗
PubMed1978

Function and dimensions of the circulatory system in anorexia nervosa.

The functional and dimensional components of the oxygen transporting system was studied in 17 female and 11 male patients suffering from anorexia nervosa. Both groups were 14.9 years old, on average, and had lost about 25% of their weight. Measurements at rest included blood and heart volume, heart rate, blood pressure, oxygen uptake (VO2), RQ, blood lactate (LA) and in 6 of the patients cardiac output. During bicycle ergometry the determinations of heart rate, blood pressure, LA, VO2 and cardiac output were repeated and maximal aerobic power was determined. A low metabolic rate with bradycardia and hypotension was apparent at rest. Blood and heart volume was decreased proportionally to the weight loss. On a given work load VO2 was lowered to the same extent as the resting metabolic rate. At maximal effort VO2 was reduced out of proportion to the circulatory dimensions and maximal heart rate was low. During exercise cardiac output was normally related to VO2 and stroke volume was maintained, indicating a normokinetic circulation and an unimpaired myocardial function. The main cause of the low maximal aerobic power seems to be the reduced muscle mass.

Adolescent↗
PubMed1978

Limb circulation in anorexia nervosa.

Blood flow, skin temperature and blood pressure of the lower limbs and the effect of indirect, radiant heat on calf blood flow and leg skin temperature was determined in sixteen children with anorexia nervosa (group A) and fourteen healthy children (group H) of the same age and body height. Calf blood flow as measured by venous occlusion plethysmography. Arm blood pressure was obtained by tourniquet and toe pressure and digital plethysmograms by a strain-gauge. Skin temperature was measured with a thermocouple. In group A calf blood flow was about 50--60% lower than the mean values observed in group H and a marked difference was maintained after the heat load. Skin temperature of the knees and toes were higher in group H. Systolic arm blood pressure and toe pressure were on the average 20 mmHg and 13 mmHg lower in group A. It is suggested that there is a heat-conserving, selective peripheral vasoconstriction in the anorexic patients.

Adolescent↗
PubMed1978

Total body potassium fat free weight and maximal aerobic power in children with anorexia nervosa.

Body composition and aerobic work performance have been studied in 5 boys and 10 girls suffering from anorexia nervosa. The average ages of the two groups of children were 15.4 (boys) and 15.2 (girls) years respectively. Measurements of body composition included height, weight (W), body potassium (40K), skinfold thickness (SFT) at triceps and subscapularis, blood volume (BV) and femoral condylar and radioulnar breadths. From these measurements estimates of fat free weight (FFW), skeletal weight (S) and lean body mass (LBM) were made. Work performance was assessed by measurement of the maximal aerobic power (VO2 max). The patients had lost on average 26% of their former body weight. The boys had on average greater than 7% of their body weight as fat compared with greater than 9% in the girls. However, the loss of weight was not solely due to loss of body fat, but could also be ascribed to a decrease in soft fatfree tissue. LBM or FFW could be estimated as well from SFT as from 40k. vo2 max averaged 1.43 1/min (35.1 ml/kg/min) in the anorexic boys and 1.24 l/min (33.2 ml/kg/min) in the girls and was associated with FFW and LBM. However, VO2 max was lower in relation to LBM than in healthy children of the same age. Thus it was suggested that the emaciation in anorexia is directly attributable to loss of both fat and muscle and accounts in part for the reduction of aerobic power observed. However, an important factor may be the debilitating effect of starvation on the patient, particularly in its advanced and later stages, which reduces his/her level of habitual physical activity.

Adolescent↗