bluuebunny/crossref_metadata_2025 huggingface dataset:
Digital arterial tone in hypertensive subjects
Authors: Nielsen Steen Levin , Olsen Niels , Nielsen Poul Ebbe
Published: April 2008

Summary. The digital arterial tone has been measured in 12 consecutively referred hypertensive subjects before and after 8 weeks treatment with propranolol. Similar measurements were performed in 12 normotensive, age‐matched controls. The study showed uniformly, that the digital arterial tone increased with falling local temperature applied at the digits (measured at 30, 20, 15, 10 and 5o C). Among the untreated hypertensive subjects the digital arterial tone was significantly higher compared to normotensive controls. After treatment with propranolol a significant increase in digital arterial tone was demonstrated, and most pronounced among the patients complaining of tendency to cold fingers. Additional body‐cooling increased arm and finger systolic blood pressure significantly, but not the digital arterial tone. The frequent Raynaud‐like symptoms in patients treated with non‐selective beta‐adrenoreceptor blocking drugs seem to be due to blockade of peripheral beta‐II adrenergic receptors giving rise to more pronounced alpha‐mediated vasoconstriction.
Human platelet thromboxane synthesis is unaffected by nicotine
Authors: Alster Pawel , Wennmalm Åke
Published: April 2008

Summary. The effect of nicotine (2times 10‐7‐2times 10_4M) on arachidonate (AA)‐induced platelet aggregation and on the bioformation of thromboxane (TxB2) in human platelets was investigated. Human platelet‐rich plasma (HPRP) and human platelet suspension (HPS) were prepared from venous blood from donors who had not taken aspirin‐like drugs for at least one week. Using HPRP, nicotine was inefficient in blocking platelet aggregation from threshold AA concentrations–in contrast to indomethacin and aspirin–and also in prolonging the interval between the addition of A A and the initiation of aggregation. In other experiments, platelet microsomes prepared from HPS were incubated with 14C‐AA in the presence of nicotine, and the labelled metabolites were separated and quantified radiocbromatographically. Addition of nicotine to the incubations did not affect the amount of TxBa formed compared to controls; indomethacin, on the other hand, efficiently inhibited TxB2 formation as did pre‐treatment of the donors with aspirin. The results indicate that human platelet cyclo‐oxygenase, unlike, for example, rabbit renal cyclo‐oxygenase, is resistant to the inhibitory action of nicotine. The possible relevance of a tissue difference for tobacco smoking is pointed out.
Intraperitoneal fluid pressure in patients with cirrhosis of the liver and in control subjects
Authors: Henriksen Jens H.
Published: April 2008

Summary. Intraperitoneal fluid pressure (IFP) was measured by a wick‐type catheter in three groups of patients: controls (patients without cirrhotic liver disease and no sign of ascites or portal venous congestion at laparoscopy), patients with cirrhosis of the liver without ascites, and cirrhotic patients with ascites. IFP was on the average –3–9 mmHg (range –7‐3 to –0–3), 1 ‐2 mmHg (range –2‐0 to 4‐3), and 11‐6 mmHg (range 0–8 to 22), respectively, all groups being significantly different (P<0–02). Furthermore, IFP was measured in anaesthetized pigs. IFP in the pigs was mean –3‐3 mmHg (range –1–5 to –5–6), a value close to that of human controls. Suction by the lymphatics and intestinal contractions‐peristalsis are suggested, but not sustained, as possible determinants of the negative normal IFP. Elevated IFP may play a role as a protective factor against formation of ascites in patients with cirrhosis.
On the necessity of strict bed rest during determination of 51Cr‐EDTA clearance
Authors: Brauner L. , Westling H.
Published: April 2008

Summary. The total plasma 51Cr‐EDTA clearance was determined twice, with about a 1‐week interval, in 60 patients with various renal diseases and stable renal function. The results were not significantly different whether the patient was confined to bed during the investigation or if the patient left the examination bed for 2–3 h of the investigation period. Furthermore, the reproducibility did not deteriorate if the patients were allowed to leave the examination bed.
Insulin clearance in normal and cancer involved human kidneys
Authors: Jonsson Olof , Granerus Göran , Kleist Håkan , Lundholm Kent , Lundstam Sven , Nilson Arne , Pettersson Silas , Schersteh Tore
Published: April 2008

Summary. Eight patients with unilateral renal carcinoma were studied concerning insulin clearance in the normal and the tumour‐bearing kidney. The arterio‐venous differences of glucose, lactate, free fatty acids and glycerol were also determined. The blood flow was measured by a dye dilution technique.

The insulin clearance was high both in the normal kidney (66 ±11 ml/min) and in the tumour involved kidney (70 ± 14 ml/min) as compared with the glomerular filtration rate (45 ± 3 ml/min and 35 ± 6 ml/min, respectively) indicating an active uptake and degradation of insulin. The insulin clearance per volume of kidney was significantly lower in the tumour‐bearing kidney. Blood flow did not differ between normal and tumour‐involved kidneys and no indications for arterio‐venous shunting in the tumours were obtained. It is suggested that the malignant transformation of the tubular cells is associated with a decreased capacity for insulin uptake and degradation.
Blood flow resistance in the hand after coarctectomy
Authors: Hanson Einar , Eriksson Bengt O. , Sivertsson Ramon
Published: April 2008

Summary. Patients with established hypertension have an increased blood‐flow resistance at maximal vasodilatation, which has been interpreted as being caused by a wall thickening in the resistance vessels. Hand blood‐flow resistance at maximal vasodilatation was estimated from intra‐arterial mean blood pressure and plethysmographically determined hand blood‐flow in ten young men, operated upon for coarctation of the aorta during childhood. The patients were compared with different reference groups examined in the same way. The resting mean blood pressure in the coarctation group was only slightly elevated, to the level of a group of patients with mild blood pressure elevation, while the blood‐flow resistance at maximal vasodilatation was markedly increased and equalled that found in a group of patients with established hypertension. This discrepancy between blood pressure and blood‐flow resistance suggests a limited reversibility of structural changes in the resistance vessels, originating from the preoperative period with high blood pressure, and might be an argument in favour of early operation and/or antihypertensive medication in children with coarctation of the aorta.
Digital pulse volume in the evaluation of haemodynamic effects of cardiac pacing
Authors: Edhag O. , Fagrell B. , Freyschuss U. , Kaijser L. , Vallin H.
Published: April 2008

Summary. 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<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.
Influence of abdominal surgical trauma upon some energy metabolites in the quadriceps muscle in man
Authors: Stjernström H. , Jorfeldt L. , Wiklund L.
Published: April 2008

Summary. Thirteen patients with gallbladder disease but otherwise healthy were studied in connection with cholecystectomy. Specimens of the lateral vastus muscle were taken by the percutaneous needle biopsy technique during anaesthesia before surgery, on two occasions during surgery and 30 min after discontinuation of anaesthesia. The muscle samples were analysed for glycogen, lactate, citrate, ATP, phosphoryl creatine, creatine and water content. Citrate and lactate concentrations in muscle increased continuously throughout the study. There were no significant changes in the concentration of glycogen, phosphoryl creatine, and ATP in muscle tissue. The increase in citrate concentration is probably related to an augmented uptake and combustion of free fatty acids and 3‐hydroxybutyrate in this situation.

The data suggest that during anaesthesia and abdominal surgery an increase in the muscle citrate concentration may contribute to the modulation of carbohydrate utilization in skeletal muscle.
Urethral Pressure Profilometry: A Low Compliant Recording System With Perfused Catheter
Authors: Engberg A. , Frank D. , Sundstrom G. , Åberg J.
Published: April 2008

Summary. A new catheter for recording the urethral closure pressure profile (UCPP) in men and women is introduced. The measuring system utilizes perfusion and saline as a transmission medium. The dynamic response of the whole catheter system as a unit was studied in vitro, and profile studies of the female urethra were performed in vivo using a solid catheter equipped with micro‐transducers as a reference. The small transmission volume and a low‐compliant perfusion gave a sufficient bandwidth for recordings of the UCPP. No significant difference was found in closing pressure and functional length in the UCPP of women between the new cather and the solid cather.
Cardiovascular response to spinal anaesthesia in elderly men: effects of head‐up tilt and dihydroergotamine administration
Authors: Bergenwald L. , Freyschuss U. , Kaijser L. , Westermark L.
Published: April 2008

Summary. In nine elderly men (mean age 60, range 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 tilt (10–15o).

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.
Pressure‐volume and airway closure relationships in each lung in anaesthetized man
Authors: Hedenstierna Göran , Bindslev Lars , Santesson Joakim
Published: April 2008

Summary. Airway closure, functional residual capacity (FRC) and transpulmonary pressure‐volume curves were assessed for each lung separately in the anaesthetized subject by means of a double lumen tracheal catheter. In the supine position airway closure occurred synchronously in the two lungs and 0–2‐0‐3 1 above FRC. The pressure‐volume curves in both lungs were rather similar and critical closing pressure (CP) was approximately 3 cmH2O in each lung. In the left lateral posture, FRC was increased in the non‐dependent and reduced in the dependent lung, while closing capacity (CC) remained unaltered. Airway closure was asynchronous and discontinuous between the two lungs. This was caused by the non‐linear transpulmonary pressure‐volume curve of the lungs, in conjunction with the vertical pleural pressure gradient. An interpulmonary ‘pendel‐luft’ phenomenon was observed in the left lateral posture, increasing inhomogeneity of ventilation. It may depend on regional differences in compliance.
Effect of short‐term C02‐breathing on the C02 content and intracellular pH in skeletal muscle of man
Authors: Sahlin K. , Freyschuss U. , Hultman E. , Sjöholm H.
Published: April 2008

Summary. 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 C02 tension increased more slowly, reaching the arterial value at the end of the CO2‐breathing period. Muscle content of total CO2 (HCO3‐ 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.
Baroreceptor reflexes after coarctectomy
Authors: Hanson Einar , Eriksson Bengt O. , Sivertsson Ramon
Published: April 2008

Summary. Patients with hypertension have an impaired baroreflex sensitivity, the reduction being proportional to the blood pressure elevation. Coarctation of the aorta is characterized by hypertension in the upper part of the body. In eight young men, operated upon for coarctation of the aorta during childhood, baroreflex sensitivity was estimated from the prolongation of the R‐R interval during the transient rise of arterial blood pressure induced by intravenous injections of small doses of angiotensin. The patients were compared with normotensive and hypertensive reference groups, of the same age and sex, who were examined in the same way. The resting mean blood pressure in the coarctation group was slightly elevated, and the baroreflex sensitivity was reduced proportionally. The fact that the baroreceptors were more sensitive than would be expected from the patients pre‐operative high blood pressure suggests that the baroreceptor‐resetting in high blood pressure is to a considerable degree reversible when the blood pressure is reduced.
MUSCLE NERVE SYMPATHETIC ACTIVITY IN HYPERTEXSIVE SUBJECTS
Authors: Wallin G.
Published: April 2008

In summary there is no difference between MSA in normotensive and hypertensive subjects that is likely to be of pathogenetic importance. We may also conclude that when high blood pressure develops slowly (irrespective of the underlying reason) baroreflex mechanisms exerted via muscle sympathetic activity are not able to counteract the blood pressure rise.
Effect of hyaluronidase on substrate exchange and blood flow in the ischaemic myocardium of the dog
Authors: Smiseth Otto A. , Refsum Helge , Vik‐Mo Harald , Mjøs Ole D.
Published: April 2008

Summary. The mechanism for reduced myocardial ischaemic injury by hyaluronidase was studied in open chest anaesthetized dogs. Repeated coronary artery occlusions were performed and the effect of hyaluronidase (225 NF units per kg) was studied during infusion of noradrenaline 0·125 mg/kg · min. Ischaemic injury was measured as the sum of ST‐segment elevations (S̀ST) at 10–15 sites. Regional myocardial blood flow was determined by tracer microspheres. Blood for metabolic studies was sampled from a local coronary vein draining ischaemic tissue and from the coronary sinus draining predominantly non‐ischaemic tissue. Hyaluronidase reduced S̀ST and increased subepicardial and transmural blood flow in ischaemic myocardium, but flow was not significantly changed in the ischaemic subendocardium or in non‐ischaemic myocardium. Hyaluronidase had no significant effect on arterio‐local venous differences of oxygen, glucose, lactate or free fatty acids across the ischaemic myocardium. In conclusion, reduction of myocardial ischaemic injury by hyaluronidase can be explained by increased collateral blood flow and not by an effect on fluxes of substrates across the ischaemic myocardium.
Moments analysis in clinical spirography—a cul‐de‐sac?
Authors: Vale J. R.
Published: April 2008

Summary. Mean transit time (MTT) and some higher moments of the forced expiratory curve were calculated at routine spirography in 190 patients with respiratory disorders. MTT was closely related to traditional indices of airflow obstruction. Within duplicates, both MTT and an index of dispersion of transit times depended strongly on expiratory time and showed a correspondingly poor repeatability.

An additive, exponential model of log normally distributed transit times could, for numerical reasons, be adapted in 61 patients only and led in these to a further impairment of precision. A corresponding model of discrete type, universally applicable by optimization, regenerated volume/time curves inaccurately. None of these infinite models proved able to eliminate the influence of expiratory endurance on transit time characteristics. This finding indicates that forced expiratory curves do not in general behave like composite exponentials.
Ventilation‐perfusion relationships in children
Authors: Hedenstierna Goran , Freyschuss Ulla , Hedlin Gunilla , Thorén Claes , Wallgren Göran
Published: April 2008

Summary. Ventilation‐perfusion relationships (V̇A/Q̇) were studied in nine lung‐healthy children, 7–15 years old, in whom a diagnostic heart catheterization was performed. V̇A/Q̇ 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 V̇A/Q̇ ratio of one. In three of the four youngest children, 10 years old or less, additional ‘high’V̇A/Q̇ regions were observed. Neither shunt, nor ‘low’V̇A/Q̇ regions were seen in any child. Arterial Po2 was above 12 kPa in all except one and no age dependence was observed.
Left ventricular response to graded isometric exercise in patients with coronary heart disease
Authors: Ehsani Ali A. , III Wade H. Martin , Heath Gregory W. , Bloomfield Susan A.
Published: April 2008

Summary. The effects of graded isometric exercise on left ventricular performance were characterized in 11 male patients (53 ± 2 years) with coronary artery disease (CAD) and in 12 normal subjects (11 male and one female, 36 ± 5 years). The echocardiographic indices of left ventricular function at rest were similar in both groups. Heart rate and blood pressure increased significantly in both groups in response to 40 and 60% of handgrip maximal voluntary contraction (MVC). Left ventricular end‐diastolic dimension increased significantly (from 50 ± 1 to 56 ± 1 mm; P < 0·01) with 60% of MVC in CAD group but not in the healthy subjects. The patients with CAD also exhibited significant (P < 0·01) increases in end‐systolic dimension (from 34 ± 1 to 40 ± 2 with 40% and to 44 ± 1 mm with 60% MVC). End‐diastolic and end‐systolic dimensions did not change during isometric exercise in the healthy subjects. Mean velocity of circumferential shortening (mVCF) increased with 60% MVC in normal subjects. In the CAD group mVCF decreased significantly (from 1.08 ± 0·06 to 0·86 ± 0·06 with 40% and to 0·74 ± 0·04 d·s‐1 with 60% MVC; P < 0·01). At comparable mean blood pressures, mVCF was significantly lower in the CAD group than in normal subjects. These results demonstrate that progressive deterioration of left ventricular function during increasing levels of isometric exercise in patients with CAD can be detected with echocardiography.
A reproducible and stable model of acute ischaemic left ventricular failure in dogs
Authors: Smiseth Otto Armin , Mjøs Ole Danbolt
Published: April 2008

Summary. A model of acute ischaemic left ventricular (LV) failure is presented. In closed‐chest anaesthetized dogs 50 μm plastic microspheres were injected repeatedly into the left main coronary artery over a period of about 40 min. The injections effected stepwise elevations of LV end‐diastolic pressure (Lvedp). Thus, Lvedp could be increased to a desired level, about 20 mmHg, in a very controlled manner. All dogs developed signs of markedly depressed LV performance. Haemodynamic conditions stabilized about 60 min after embolization, and then remained essentially stable for at least 75 min. Lvedp increased from 5·7 ± 0·6 before to 26·1 ± 0·8 mmHg (mean ± SEM) 60 min after embolization. The maximum LVdP/dt decreased from 2696 ± 169 to 1823 ± 98 mmHg·s‐1, cardiac output decreased from 2·81 ± 0·20 to 1·98 ± 0·14 1·min‐1 and mean aortic blood pressure decreased from 144±4 to 127±3 mmHg, while total peripheral resistance increased from 56±3 to 69±3 mmHg·l‐1·min. Myocardial blood flow decreased from 103±7 to 79 ±6 ml·min‐1·100 g‐1 and myocardial oxygen consumption decreased from 12·5±0·9 to 8·3·0·8 ml· min‐1·100 g‐1. Myocardial uptake of lactate and free fatty acids decreased markedly. Electrocardiography showed signs of acute ischaemia. There were no deaths due to ventricular fibrillation. Morphological studies showed multiple small infarcts throughout the entire LV. In conclusion, repeated coronary embolization with 50 μm plastic microspheres, guided by the rise of Lvedp represents a simple and reproducible method for induction of uniform and stable acute LV failure.
Electrocardiographic and vectorcardiographic findings in asymptomatic young men with primary T‐wave abberations in the electrocardiogram. Relationship to sympatho‐adrenal activity at rest and during different stress tests
Authors: Atterhog J.‐H. , Eliasson K. , Hjemdahl P.
Published: April 2008

Summary. Twelve asymptomatic men aged 18–19 years with flat, notched or inverted precordial T waves without concomitant ST depression (group T) were compared to thirteen age‐matched controls with normal electrocardiograms (group C). Orthogonal leads, spatial vectorcardiography and sympatho‐adrenal activity, as reflected by plasma catecholamines, were studied at rest and during mental stress (Stroop's colour word conflict test), isometric exercise (hand grip) and a cold pressor test. The groups had similar heart volumes and physical work capacity. Group T showed higher resting supine systolic blood pressure (140±15 mmHg vs. 121±8 mmHg, P<0·001) and plasma noradrenaline (1·82±0·79 nmol 1‐1vs. 1·25±0·49 nmol 1‐1, P<0·05) whereas heart rate, diastolic blood pressure and plasma adrenaline were similar in the two groups at rest. Increases in diastolic blood pressure and plasma adrenaline were larger in group T in connection with each of the stressful provocations. The magnitude of the T‐wave aberrations in the electrocardiogram and the orthogonal leads in the vectorcardiogram as well as the spatial QRS‐T angle were positively correlated to the plasma noradrenaline levels at rest. Changes of the T‐wave aberrations in connection with stress were variable. The changes were positively correlated to heart rate and adrenaline during mental stress, to adrenaline during isometric exercise and to heart rate and noradrenaline during cold provocation. The present study demonstrates increased sympathetic tone at rest and increased reactivity in connection with stress in otherwise healthy young subjects selected on the basis of T‐wave aberrations often considered as indicative of organic heart disease. The findings suggest that the T‐wave aberrations were caused by increased sympathetic discharge.
Heparin‐released lipolytic activity in the forearm vascular bed in patients with hypertriglyceridaemia
Authors: Eklund Brita , Söderberg Birgitta
Published: April 2008

Summary. Hypertriglyceridaemia (HTG) may be caused by increased production or decreased removal of very low density lipoproteins (VLDL) or by a combination of these mechanisms. A decreased lipoproteinlipase activity (LLA) in the vascular wall of the tissues could be the mechanism of impaired removal. Therefore, the release of lipase activity from the forearm musculature after regional arterial injection of heparin was studied in healthy volunteers and patients with HTG.

Heparin was injected in the doses 1·5, 15 and 150 i.u. and arterial and deep venous blood was sampled simultaneously at short intervals and analysed for LLA using intralipid with triple 14C‐oleate as substrate. There was no significant difference in release of lipolytic activity between the groups and there was no significant correlation between plasma triglyceride concentration and LLA release in the HTG group or the whole material. Thus, deficient skeletal muscle LLA does not seem to be a general causative mechanism in HTG.
Effects of externally applied compression on blood flow in subcutaneous and muscle tissue in the human supine leg
Authors: Nielsen Henrik Vagn
Published: April 2008

Summary. The effect of positive tissue pressure on blood flow in subcutaneous adipose tissue and skeletal muscle tissue was studied in eight healthy humans resting in the supine position. Blood flow was measured by the local 133Xe clearance technique in the mid‐calf region. Tissue pressure was increased by inflating a whole leg cuff to pressure levels between 10 and 60 mmHg.
Metabolic heat production in isometric ischaemic contractions of human adductor pollicis
Authors: Wiles C. M. , Edwards R. H. T.
Published: April 2008

Summary. The rate of intramuscular temperature rise (dT/dt) has been measured in ischaemic isometric contractions of adductor pollicis in man as an index of the rate of energy turnover. Experiments were designed so as to compare dT/dt in contractions made at a constant force but at differing intramuscular temperatures or degrees of ischaemic fatigue. In the same experiments relaxation rate was measured.

As intramuscular temperature was raised from 25 to 37°C, dT/dt increased with a Q10 of 1·8 and was closely correlated with relaxation rate. During constant force submaximal ischaemic contractions dT/dt fell, failed to recover with ischaemic rest but did so within 10 min of restoration of the circulation. During the fatiguing contraction and recovery thereafter dT/dt was linearly correlated with relaxation rate.

The results show that the rate of energy turnover at a constant force is susceptible to change in association with alteration in the contractile speed of the muscle. It is suggested that relaxation rate may be used as an index of the capacity of the muscle to liberate energy.
Failure of endurance training to alter the cardiovascular response to static contraction
Authors: Seals Douglas R. , Sinacore David R. , Hurley Ben F. , Nemeth Patti M. , Hagberg James M.
Published: April 2008

Summary.The purpose of this study was to determine whether endurance training alters the cardiovascular response to static contractions of the trained, but not untrained, musculature. Six healthy, untrained males (aged 23–36 years) underwent 10–12 weeks of intensive training involving both cycling and running. Peak v̇O2, on the bicycle ergometer, v̇O2max during graded treadmill running and concentrations of citrate synthase (CS) and malate dehydrogenase (MDH) in the vastus lateralis muscle were measured before and after training. Subjects performed static leg extension and forearm extension at 30% of maximal voluntary contraction until exhaustion before and after training. Heart rate (HR), systolic (SBP) and diastolic (DBP) blood pressure were measured at rest, and in addition to perceived exertion (PE), every 30 s during contraction. Endurance training elicited significant increases in peak v̇O2(360%), v̇O2max (32%), Cs(25'Yn) and Mdh(42%) (all P < 0.05).HR at rest was significantly lower (P < 0.05) after training, while SBP and DBP were unchanged. HR, SBP, DBP and PE increased throughout both types of static contractions. However, the magnitude of the increases were unaffected by training. In contrast to recent findings, these results suggest that the increases in heart rate and blood pressure in response to static contraction are not altered after endurance training in either the trained or the untrained muscle groups.
Superior sagittal sinus blood flow in the dog measured by an electromagnetic flow meter. A comparison with a radioactive gas elimination method
Authors: Elfverson J. , Larsson L. E.
Published: April 2008

Summary. A simple method for continuous measurement of superior sagittal sinus blood flow (SSBF) in dogs, using an electromagnetic flow meter around the intact vessel, is presented. This method is compared with a procedure measuring radioactive gas elimination upon intra‐arterial indicator injection. A good correlation between the cerebral blood flow (CBF), calculated from the fast component of the elimination curve and SSBF (r=0·96) was found within a CBF range of 50–200 m1/100 g min.
Platelet aggregability in smoking and non‐smoking subjects
Authors: Carlsson Inger , Wennmalm Åke
Published: April 2008

Summary. The hypothesis was investigated that the arachidonic acid (AA) system has a different impact on platelet function in smoking compared to non‐smoking subjects. Arterial blood was sampled from smokers and non‐smokers, and platelet‐rich plasma (PRP) was prepared. There were no differences in sex and age distribution between the groups. One portion of the PRP was used to determine the lowest amount of AA required to induce platelet aggregation. In other portions the endogenous antiaggregatory (prostacyclin/PGI2/‐like) activity in the blood was determined, after reinforcing it with theophylline.

There was no difference between smokers and non‐smokers regarding the amount of AA required to induce platelet aggregation. In fresh PRP prepared from blood from non‐smoking subjects theophylline (10‐4 M) induced a 12–17% inhibition of the ADP‐induced aggregation of platelets, indicating the presence of endogenous sub‐threshold concentrations of PGI2, ‐like activity in their blood. The corresponding inhibition in fresh PGI2 prepared from blood from smokers was significantly lower (4–7%), suggesting lower endogenous concentrations of PGI2‐like activity in their blood, or alternatively, decreased platelet sensitivity to the action of such activity.

From these data we conclude that smokers differ from non‐smokers with regard to their platelet function: platelet aggregability in response to AA is unaffected, while the endogenous anti‐aggregatory power in the plasma is decreased. These observations may be of significance for the cardiovascular hazards connected with smoking.
Effects of high doses of insulin on systemic haemodynamics and regional blood flows in dogs
Authors: Reikerås O. , Gunnes P.
Published: April 2008

Summary. This study describes the effects of a wide range of plasma concentrations of insulin on systemic haemodynamics and free fatty acids (FFA) and the effect of a high dose of insulin on regional blood flows in the femoral, carotid, mesenteric and renal arteries. Insulin was infused in 10 dogs at rates of 4, 8, 16, 32, 64 and 128 IU/kg/h, and the experiments were concluded with a bolus injection of 300 IU. Plasma glucose concentrations were kept constant during the experiments. A dose‐related increase in the maximum rate of left ventricular pressure rise, stroke volume and cardiac output, and decrease in total peripheral resistance was found with insulin infusion rates up to 64 IU/kg/h. Heart rate and mean aortic blood‐pressure were unchanged. The maximum antilipolytic effect was obtained at an infusion rate of 16 IU/kg/h. Insulin was given as a bolus dose of 300 IU in 6 dogs. Blood‐flow was increased in all vascular beds, but insulin caused a redistribution of cardiac output. The greatest increases occurred in the femoral and carotid vascular beds, and the least occurred in the renal bed. Mesenteric blood‐flow was increased in proportion to cardiac output. The results suggest that insulin exerts combined positive inotropic and vasodilating effects at high dose levels, which result in improved regional perfusion. It may be a potentially useful clinical agent with special benefit under circumstances where enhanced cerebral blood‐flow is of importance.
Effect of changes in posture on circulatory homeostasis in patients with the nephrotic syndrome
Authors: Geers A. B. , Koomans H. A. , Mees E. J. Dorhout
Published: April 2008

Summary. To assess whether the upright posture causes circulatory hypovolaemia in patients with the nephrotic syndrome (NS), we studied 12 subjects with NS and 12 healthy subjects during recumbency, 110 min of standing, followed again by recumbency. Control blood‐pressure was 134/88±4/3 mmHg in the patients and 113/75±2/3 mmHg in the normal subjects (P<0.01), and remained higher in the patients throughout the procedure. Heart rate was continuously higher in the patients (P<0.05), but acceleration on standing was normal. The blood volume, which was not different during recumbency, had fallen below that in normal subjects after 25 min of standing (P<0.05), due to excessive plasma volume reduction (‐16.8±0–8% in the patients against ‐11.7±1.2% in the normals, P<0.02). Plasma renin activity (PRA) was higher in the patients while recumbent (P<0.001) but not during standing, due to a blunted response in some. No significant differences in plasma noradrenaline were found, but four patients reacted with an excessive rise in plasma noradrenaline and heart rate. This subset, which had high PRA levels as well, comprised the only subject who experienced orthostatic hypotension.

It is concluded that during standing an excessive drop in plasma volume leads to a lowered blood volume in NS patients. This forms a paradox with the heart rate acceleration and noradrenaline levels, which were mostly normal, and with the blood‐pressure, which remained slightly elevated. Even in a few patients with enhanced stimulation of heart rate and noradrenaline, blood‐pressure was found to be high in the majority of cases. PRA was usually found to be increased but, in part, independent of posture.
Computerized single‐breath nitrogen washout in children: variability and reproducibility
Authors: Teculescu D. B. , Pham Q. T. , Hannhart B. , Melet J. J. , Marchand M. , Henquel J. Cl.
Published: April 2008

Summary. The variability, short‐term (1 hour) and long‐term (2 weeks) reproducibility of the variables derived from the single‐breath N2 test were evaluated in a group of 56 healthy children aged 10 to 16 years with a computerized system. The variability was low for vital capacity and total lung capacity (coefficient of variation less than 3%), moderate for residual volume and phase III N2 slope (9 and 13%) and very high for closing volume (more than 50%). A closing volume could not be identified by the computer algorithm in 18.3% of the trials. The reproducibility of the variables was satisfactory both at 1 hour and at 2 weeks, with the exception of the closing volume, whose increase at 2 weeks seemed to be due to methodological factors. We conclude that reliable results of static lung volumes and phase III N2 slope, but not of closing volume, may be obtained in children by a computerized system in epidemiological studies.
Pulmonary clearance of inhaled 99mTc‐DTPA: effect of the detergent dioctyl sodium sulfosuccinate in aerosol
Authors: Evander E. , Wollmer P. , Jonson B.
Published: April 2008

Summary. The influence of the detergent dioctyl sodium sulfosuccinate on clearance from the lungs of inhaled technetium‐99m‐labelled dietylenetriamine pentaacetate (99mTc‐DTPA) was studied in twelve rabbits. An aerosol of dioctyl sodium sulfosuccinate or its vehicle alone was administered for 5 min prior to aerosolized 99mTc‐DTPA via a bag‐in‐bottle system. Time‐activity curves were obtained from the right lung with a gamma camera. In rabbits given detergent, clearance of 99mTc‐DTPA was significantly faster than in rabbits given vehicle alone. No changes were seen in arterial Po2 and compliance. Our data indicates that the transfer of 99mTc‐DTPA from alveoli to blood can be accelerated by administration of the detergent dioctyl sodium sulfosuccinate without any dramatic change in surface tension. Clearance of 99mTc‐DTPA may be a very sensitive indicator of altered surfactant function.
Measurement of oxygen and carbon dioxide partial pressures in synovial fluid after tonometry
Authors: Geborek P. , Lindoff B. , Valind S. O.
Published: April 2008

Summary. A commercially available gas analyser was used to measure tension of oxygen (Po2) and carbon dioxide (Pco2) in synovial fluid samples after tonometry. Measured values of Pco2 were close to the expected (median difference 0·2 kPa, range ‐0·4 to 0·4) within the analysed concentration range of 4·10 kPa. No consistent difference between measured and expected values of Po2 were found for oxygen in the range 3·11 kPa (median difference 0·1 kPa, range ‐0·3 to 1·2). For oxygen tensions below 3 kPa, however, the measured values invariably overestimated the actual Po2, the errors ranging from 0·3 to 1·9 kPa, median 1·1. The importance of proper handling of samples was investigated and storage for 1 h at 0°C in plastic syringes resulted in elevation of the Po2 levels measured (range of elevation 0·2 to 3·6 kPa, median 1·15), whilst no significant differences were found when stored in glass syringes. Within the limits stated, commercially available gas analysers may thus be used to investigate these parameters related to local tissue metabolism in effusive joint conditions.
Time course and nature of postprandial haemodynamic changes in normal man
Authors: De Mey C. , Hansen‐Schmidt S. , Enterling D. , Meineke I.
Published: April 2008

Summary. The present study describes the nature and time course of the cardiovascular and neuro‐endocrine changes that followed a standard 3100 kJ cold meal in 12 supine and fasting normal men who were studied in a balanced cross‐over design. Heart rate, blood pressure, systolic time intervals and estimates of cardiac performance by impedance cardiography were measured every 10 min up to 4 h after eating. Eating caused a rapid and short‐lasting increase in systolic blood pressure, estimated stroke volume and maximum velocity of impedance changes. Eating also caused a rapid and more protracted decrease in diastolic and mean blood pressure, PEP‐i, QS2‐i and estimated systemic vascular resistance with an increase in heart rate and estimated cardiac output. In the later phase of the profiling a drop in LVET‐i was also observed. The differences vs. fasting were statistically significant and judged to be biologically relevant. Venous plasma noradrenaline rose during eating as a consequence of the postural change, but eating itself did not alter venous plasma noradrenaline, and plasma adrenaline even tended to decrease. This reflects both the roughness of venous catecholamines in estimating adrenergic changes and the complexity of the underlying mechanisms and related reflexes.
Colloid osmotic and hydrostatic pressures and energy metabolism in high‐protein joint swelling. A preliminary study of traumatic effusions of the knee
Authors: Harilainen A. , Ahlqvist J. , Lalla M. , Myllynen P. , Rokkanen P.
Published: April 2008

Summary. In 10 patients referred to arthroscopy with traumatic effusions of the knee, the protein concentration of the synovial fluid (SF) correlated to its colloid osmotic pressure (πsf). The πsf did not correlate to the poorly determined hydrostatic pressure (Psf) in extended or slightly flexed joints or to the SF volume (Vsf). SF hypoxia correlated to πsf and to the number of intra‐articular erythrocytes, but not to the determined Psf or Vsf. SF hypoxia correlated to increase in lactate and decrease in pH, fitting enhanced anaerobic glycolysis. In addition, SF erythrocyte counts correlated to lactate increase. During a 5‐min period of high Psf induced by flexion, the Psf decreased, and even more markedly so after the joints had been rinsed with saline. The results suggest that rinsing of joints in order to lower the πsf and to remove erythrocytes is of benefit in cases of traumatic effusion.
Cigarette smoke‐induced elevation of plasma neuropeptide Y levels in man
Authors: Rudehill A. , Franco‐Cereceda A. , Hemsén A. , Stensdotter M. , Pernow J. , Lundberg J. M.
Published: April 2008

Summary. The purpose of the present study was to evaluate whether neuropeptide Y, which coexists with noradrenaline in sympathetic nerves, may be released upon cigarette smoking. Therefore, previously non‐smoking adults inhaled smoke from one cigarette once every minute during 10 min, and the effects on blood pressure, heart rate and plasma levels of noradrenaline and neuropeptide Y were analysed. A prompt rise of systolic blood pressure and heart rate (by 25 mmHg and 30 beats min‐1, respectively) was observed upon smoking. Systemic plasma levels of noradrenaline and neuropeptide Y were significantly elevated after 3 and 5 min of smoking, respectively, and reached maximal values (neuropeptide Y from 32±4 to 49± 7pmoll‐1, and noradrenaline from 0.72±0.16 to 1.8±0.44 nmol 1‐1) 2–5 min after the smoking period. It is concluded that smoking in man is associated with increased plasma levels of both noradrenaline and neuropeptide Y, suggesting release of these agents. Since neuropeptide Y is a potent vasoconstrictor, the present data suggest that this peptide may contribute to the smoke‐induced cardiovascular response.
Beta‐adrenergic blockade does not influence the thermogenic response to a mixed meal in man
Authors: Thörne A. , Wahren J.
Published: April 2008

Summary. The sympathetic nervous system has been implicated in the regulation of glucose‐induced thermogenesis in man. The present study was undertaken to examine the influence of a pharmacological beta blockade on the thermogenic response after ingestion of a mixed meal. Ten healthy male volunteers were examined on two occasions, once during intravenous administration of a beta‐blocking agent (Series 1) and once without (Series 2). Five subjects received propranolol and the other five atenolol. Two subjects were also studied on a third occasion after 1 week of oral propranolol medication (Series 3). Continuous respiratory gas exchange measurements were carried out for 1 h in the basal state and then for 3 h postprandially. The subjects ingested a standardized test meal in liquid form. After the meal oxygen uptake and energy expenditure both rose markedly during the first hour and then reached a relatively stable plateau. The average increase in oxygen uptake above basal during the whole study period was 27.0±1.4 vs. 26.7±1.4% (NS) in Series 1 and 2, respectively. The corresponding values for energy expenditure were 28.6±1.4 vs. 28.6±1.6%. Also in absolute terms, the increments above basal did not differ between the two series. Moreover, the basal measurements and the response to the meal were no different in the subjects in Series 1 receiving the selective beta‐1 antagonist and the non‐selective blocker, respectively.

In conclusion, the present findings indicate that in healthy man, beta‐adrenergically mediated sympathetic nervous system activity does not significantly influence the magnitude of the thermogenic response to a mixed meal.
Plasma noradrenaline and dopamine in renin‐mediated hypertension
Authors: Herlitz H. , Hjemdahl P. , Delin K. , Granerus G. , Aurell M.
Published: April 2008

Summary. Noradrenaline (NA) and dopamine (DA) have opposite effects on the kidney; NA causes vasoconstriction and increased sodium reabsorption while DA promotes vasodilation and natriuresis.

In 15 patients investigated for renin‐mediated hypertension measurements of plasma renin activity (PRA), NA and DA concentrations were made in arterial and renal venous blood from both kidneys before and after acute stimulation of renin release by i.v. dihydralazine.

Nine patients had unilateral renin secretion and were classified as renin‐positive, while the remaining six patients were renin‐negative. Renin‐positive patients had higher arterial and renal venous PRA, NA and DA levels than the negative ones. In the renin‐positive group V‐A differences for NA and DA were present on both sides despite unilateral secretion of renin. NA but not DA levels were higher in the renin‐secreting kidney, which can partly be explained by the reduced plasma flow to the involved kidney.

After dihydralazine the arterial NA and DA rose similarly in renin‐positive and renin‐negative patients, while PRA rose only in the renin‐positive cases. In the renin‐positive patients where stimulation of renin secretion caused a marked increase of the PRA gradient on the affected side only, renal gradients for NA and DA increased bilaterally. The increase in DA was more pronounced than that of NA yielding a rise in DA/NA ratio on the affected side. Arterial PRA was positively correlated to the plasma concentrations of NA and DA. V‐A differences for PRA and NA or DA were positively correlated on the involved renin‐secreting side.

In summary, patients with renin‐dependent hypertension have elevated plasma NA and DA concentrations. Stimulation of renin release by dihydralazine increases the DA/NA ratio in arterial and renal venous blood indicating release of ‘precursor dopamine’ from noradrenergic fibres and/or activation of dopaminergic nerves. There seems to be a relationship between renal nerve activity and renin release in renin‐dependent hypertension.
A non‐invasive approach to cardiac autonomic neuropathy in patients with diabetes mellitus
Authors: Weise F. , Heydenreich F.
Published: April 2008

Summary. The purpose of this study was to obtain information regarding the participation of the sympathetic nervous system in cardiac autonomic neuropathy in patients suffering from diabetes mellitus employing spectral analysis of heart rate variability in the supine and standing posture. Ten insulin‐dependent diabetic patients (29 ± 2 years) with a short to moderately long duration of diabetes (11 ± 1 years) and cardiac vagal neuropathy based on measurements of respiratory sinus arrhythmia were compared to 10 healthy volunteers (27 ± 1 years) before and after the administration of atropine and atropine plus propranolol. In diabetic patients the reactivity in total power (ΔTP) from supine to upright position was significantly lower compared to control subjects before and after atropine. There was no significant difference in ΔTP between diabetics and controls after atropine plus propranolol. The magnitude of TP increase is essentially due to the increase of blood pressure related heart rate fluctuations (ΔMF) from lying to standing and dependent on β‐adrenergical efferent activity to the heart. In diabetic patients as well as in normal subjects under the influence of atropine plus propranolol the ΔMF power was significantly lower compared to the un‐medicated control and atropine group. There was no significant difference between diabetics and controls after combined autonomic blockade. It was concluded that ΔMF heart rate spectral power could serve as an indirect, non‐invasive, quantitative and sensitive marker of early cardiac sympathetic damage.
Myoglobin and enzyme adaptations in erector spinae muscles in thoracal scoliosis
Authors: Jansson E. , Sylvén C. , Bylund P.
Published: April 2008

Summary. Bilateral biopsies from the erector spinae muscles were taken during surgery from 10 females and two males (mean age 14, range 13–17 years) with thoracal scoliosis for 6 years (range 2–11 years). The biopsies were analysed for myoglobin (MYO), citrate synthase (CS) and creatine kinase MB (CK‐MB). The severity of scioliosis was estimavoted by Cobb's angle, the greater the angle the more severe the disease. The convex/concave side ratio (CVX/CCV) was for CS l·3±0·4 (P<0·01), CK 0·9 ± 01 (P<0·05), CK‐MB 1·6±0·4 (P<0·01) and for MYO 1·1±0·2 (P>0·05). No significant correlations were found between the CVX/CCV for CS, CK or CK‐MB on the one hand and the Cobb's angle on the other. The CVX/CCV for MYO was, however, directly related to the angle (r= 0·80, P<0·01). For the lower range of angles (≤59°) the CVX/CCV for MYO was below unity (0·88, P>0·05) and for the larger angles (>59°) above unity (1·23, P<0·05). In conclusion, a dissociation in the adaptive response of m. erector spinae in scoliosis between mitochondrial enzyme and myoglobin content was demonstrated.