bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of two different preparations of somatostatin on intra‐portal pressure in patients with liver cirrhosis
Authors: Thulin Lars
Published: April 2008

Summary. Somatostatin has been found by most authors to reduce splanchnic blood flow and hepatic venous wedge pressure. High success rates in treating oesophageal varicose bleeding have been reported by some authors, while others have been unable to confirm these findings. A reason for the discrepancies might be that different preparations of somatostatin were used. Consequently, two preparations of somatostatin were administered to three cirrhotic patients as 60‐min infusions at a dosage of 250 μg/h. The intra‐portal pressure was measured before and during the infusions and found to be unaffected by both preparations. The findings suggest that previously demonstrated reductions in portal pressure may have been of brief duration, possibly due to vascular autoregulation.
Insulin is the mediator of feecling‐related thermogenesis: insulin resistance and/or deficiency results in a thermogenic defect which contributes to the pathogenesis of obesity
Authors: Felig Philip
Published: April 2008

Summary. Obesity is characterized by insulin resistance which predisposes to the development of impaired glucose tolerance. It is postulated that in addition to its role in carbohydrate metabolism, insulin is the mediator of feecling‐related increases in thermogenesis (the thermic effect of food and dietary‐induced thermogenesis). The development of insulin resistance and/or deficiency is postulated to result in a decrease in feecling‐related, insulin‐mediated thermogenesis. As a consequence of this thermogenic defect there is an increase in efficiency of weight gain which accelerates the development and facilitates the maintenance of the obese state. Abnormalities in the insulin axis are thus not only involved in the pathogenesis of the carbohydrate intolerance of obesity but are also proposed as having a central role in a dysregulation of energy balance which contributes to the pathogenesis of obesity.
Total body bone mineral in vivo by dual photon absorptiometry. I. Measurement procedures
Authors: Gotfredsen Anders , Borg Jens , Christiansen Claus , Mazess Richard B.
Published: April 2008

Summary. A dual photon scanner using a 1 Ci 153Gd source, a NaI detector, traditional electronics and a desktop computer, was constructed. Software for the computation of the total body bone mineral (TBBM) was developed. Non‐linear influences such as deadtime due to high count rates, patient scatter and Compton effects were investigated and correction algorithms were introduced in order to obtain exponential attenuation. System precision was measured on a bone‐aluminium standard (CV=2·6%) and system linearity was assessed on aluminium pieces (r=0·999, SEE=3·0%). Short‐term precision in vivo was tested on 15 healthy subjects scanned twice with a 2‐month interval (CV=2·4%). Long‐term reproducibility in vivo was tested on two healthy subjects scanned eight times with 1‐month intervals (CV=1·9% and 3·2%). The influence of patient orientation was investigated on two skeletons. No significant difference was found between anatomical and random orientation. It was concluded that the precision errors were small, therefore making the method applicable not only in cross‐sectional studies but also in longitudinal studies designed to investigate the loss or gain of total bone mass in patients suffering from calcium metabolic disorders.
Supine and sitting maximal workload difference and response to long‐term enalapril therapy in congestive heart failure
Authors: Pöyhönen Lauri
Published: April 2008

Summary. Maximal workloads in supine and sitting bicycle stress tests were compared in 12 patients with congestive heart failure during long‐term therapy with the vasodilator enalapril. The response to the therapy was observed with the supine and sitting bicycle stress tests and gated equilibrium ventriculography.

The maximal workload was 68 W in the supine position and 84 W in the sitting position; the mean difference was 15 W. The difference was highly significant (P < 0–001). Both the supine and sitting workloads were significantly higher (P < 0–02 and P < 0–05) in the enalapril group than in the placebo group. The findings in the gated equilibrium ventriculography were not significantly different between the two groups.
TRANSPORT BY GAS‐PHASE DIFFUSION: LESSONS LEARNED FROM THE HEN'S EGG
Authors: Rahn H. , Paganelli C. V.
Published: April 2008

Diffusive gas transport obeys laws which differ from those of con‐vective transport. Diffusive gas transport can be described as an elite transport system because it not only distinguishes between O2, CO2, and water vapor molecules, but it is also influenced by barometric pressure and the presence of particular inert gas species. In the presence of air binary diffusion coefficients are applicable, but in the presence of He or SFg effective diffusion coefficients must be used.
An evaluation of finger systolic‐pressure response to local cooling in the diagnosis of primary Raynaud's phenomenon
Authors: Corbin D. O. C. , Wood D. A. , Housley E.
Published: April 2008

Summary. Finger systolic‐pressure (FSP) in response to local cooling has been evaluated as a diagnostic test in 28 females with primary Raynaud's phenomenon (PRP). The mean FSP (%) at 15oC and 10oC was significantly lower in the patients than in 28 age‐ and sex‐matched controls but there was a large overlap in the individual responses. Diagnostic sensitivity of FSP (%) at 10oC was only 57%. Increasing the sensitivity of the test lowered the specificity as the number of false positives rose. This also reduced the predictive value for a positive test. As a diagnostic test of PRP in individuals, the measurement of FSP appears to be of limited value, except in severe cases when complete vessel closure often occurs. Measurement of FSP will classify groups correctly and this objective physiological measure of Raynaud's phenomenon may have a place in group comparisons.
Effect of nicotine on coronary blood‐flow in man
Authors: Kaijser Lennart , Berglund Bo
Published: April 2008

Summary. The effect of 4 mg nicotine administered in a chewing gum on coronary haemodynamics and oxygen transport, was studied by coronary sinus catheterization in eight healthy non‐smoking men. Measurements were made of coronary sinus blood‐flow (CSF) by thermodilution and arterial‐coronary sinus (a‐cs) O2‐difference together with heart rate and intra‐arterial pressure both at rest, and during, atrial pacing with and without nicotine. Nicotine increased myocardial oxygen consumption (MVO2) more than expected from the increase in the rate‐pressure product. The increased MVO2 was covered only partly by increased coronary blood‐flow; especially during and after pacing an increased a‐cs O2‐difference contributed significantly. This differed from the response when MVO2 was increased by atrial pacing alone, in which case the whole increase in MVO2 was covered by increased flow. The results suggest that nicotine affects coronary vascular resistance and blood‐flow indirectly through a vasodilatory effect, by mechanisms related to the increased cardiac work, and directly through a vasoconstrictory effect. The suggested vasoconstrictor component is moderate in the non‐ischaemic human heart.
The effect of posture and pH on solid and liquid oesophageal emptying
Authors: Maddern Guy J. , Slavotinek John P. , Collins Peter J. , Jamieson Glyn G.
Published: April 2008

Summary. Oesophageal emptying of solids and liquids has been assessed in normal subjects using radionuclide techniques. The solid bolus comprised a 10 g disc of cooked minced beef which was labelled with 160 μCi; 99m Tc macro‐aggregated albumin (MAA). The liquid bolus consisted of 15 ml of water labelled with 300 μCi; 99m Tc. Studies were performed in the upright and supine positions and repeated after ingestion of 30 ml of 0.1m HC1 diluted to pH 1.6. Solid and liquid assessments were performed separately with a scintillation camera positioned posteriorly. Subjects were instructed to swallow at the commencement of the test and at 15 s intervals subsequently, until the bolus entered the stomach.

Oesophageal emptying in the supine position was significantly slower than emptying in the upright position. This was true for both solid and liquid emptying, in the neutral and in the acidified oesophagus. Emptying of a solid bolus did not appear to be influenced by oesophageal pH. However, emptying of a liquid bolus was significantly slower when the oesophageal pH was acid, for both the supine and upright positions.

We conclude that the supine posture delays both liquid and solid oesophageal emptying. The presence of acid in the oesophagus at a pH of 1.6 delayed liquid emptying, but not solid emptying, from the oesophagus.
The blood supply to fingers during Raynaud's attack: a comparison of laser‐Doppler flowmetry with other techniques
Authors: Engelhart Merete , Nielsen Henrik V. , Kristensen Johannes K.
Published: April 2008

Summary. Responses to combined body and finger cooling were recorded by laser‐Doppler flowmetry, Xenon‐113 washout and strain‐gauge plethysmography in 22 patients (seven patients with primary Raynaud's phenomenon (PR) and 15 with generalized scleroderma (GS)) and nine healthy, warm‐handed subjects.

Finger systolic blood‐pressure decreased to zero in 100% of the patients, after body and finger cooling as measured with strain‐gauge plethysmography. With the laser‐Doppler flowmeter a low‐positive blood‐pressure was registered in two patients.

The duration of a Raynaud's attack was found to vary from 0.5 to > 5 minutes as observed by the laser‐Doppler flowmeter.

Xenon‐133 washout from the fingertips, during a zero blood‐flow situation, insignificantly deviated from the washout during vascular occlusion.

It is concluded that; (1) the elicitation and duration of Raynaud's phenomenon could be clearly observed by laser‐Doppler flowmetry; (2) the zero blood‐flow observed by laser‐Doppler flowmetry could be confirmed by Xenon‐133 washout and (3) in GS cases, the laser‐Doppler flowmetry seemed more sensitive than the strain‐gauge, at extremely low blood flow values.
Acute myocardial infarction: an episodic event of several coronary spasms followed by dilatation?
Authors: Gasser R. , Dienstl F.
Published: April 2008

Summary. Acute myocardial infarction (AMI) can no longer be considered as a single event, but as a series of episodes. In most of the cases, the initial event may be the induction of a severe spasm of the coronary artery by vasoconstrictive substance released from aggregated platelets. These spasms are followed by dilatation, which is caused by substances set free from the ischemic tissue. Dilatation then results in a washing‐out of vasoactive mediators (as well as myoglobin) and platelets, which is reflected as a peak in the blood myoglobin concentration—time curve. The local depletion of vasodilative metabolites allows a further contraction of the coronary vessel. A new accumulation of platelets then stimulates another spasm. This vicious circle (thrombo‐ischemic re‐entry‐mechanism) is repeated several times and can be interrupted by the systemic administration of thrombolytic drugs (streptokinase).
QT and QT‐peak interval measurements. A methodological study in patients with subarachnoid haemorrhage compared to a reference group
Authors: Rudehill A. , Sundqvist K. , Sylvén C.
Published: April 2008

Summary. To study the properties of QT and QT‐peak intervals, ECGs were compared between 56 consecutive patients who were suffering from subarachnoid haemorrhage (SAH) and 50 reference subjects. The routine QTC interval was compared to the mean QTC from all of the 12 leads with identifiable U waves and to the mean QT‐peake. The interval between peak and end of T(Tp‐ Te) was subsequently calculated. In the reference group the mean QT‐peak correlated with the mean QT(r=0.925). The rate‐dependence of the mean QT‐peak was not different from that of the mean QT and showed the same correlation (r= ‐0.607 and ‐0.630, respectively). No rate‐dependence for the Tp‐Tc interval could be demonstrated. Following SAH, ECG abnormalities were most pronounced after 8–9 days, and increased with age and the degree of cerebral dysfunction. Two patient groups, where the mean QTc of each particular patient was either below (n=27) or above (n=29) the reference limit, were analysed. For the group without an abnormally prolonged mean QTc, the average of the individual mean QTc was significantly longer than in the reference group. Both groups had longer mean QT‐peakc intervals than the reference group. About 70% of the patients with an abnormally prolonged mean QTC also had a prolonged mean QT‐peakc interval, while the rest had a prolonged Tp‐Tc interval; simultaneous prolongation of these two intervals also occurred. Prolongation of the Tp‐Tc interval did not occur in the group without an abnormally prolonged mean QTc. Routine QTC and mean QT‐peakc had sensitivities of 96% and 67% respectively, specificities of 76% and 96% and predictive values of 81% and 95%.

In conclusion, the routine QTC measurements, without reference to an identified U wave, may result in falsely prolonged estimates of cardiac repolarization time. In this respect the mean QT‐peakc may provide additional information. In the majority of patients the prolonged mean QTC was dependent on a disturbed rate‐dependent function (prolonged mean QT‐peakc) while some patients had an increased asymmetry of the repolarization process within the myocardium (prolonged Tp‐Tc).
The effects of β‐blockade on electrically stimulated contraction in fatigued human triceps surae muscle
Authors: Hughson R. L. , Green H. J. , Alway S. E. , Patla A. E. , Frank J. S.
Published: April 2008

Summary. The contractile characteristics of the triceps surae muscle group were examined before and after repeated isometric contractions in two groups of eight healthy young males. Single twitches and trains of stimuli at 10, 20, 50 and 100 Hz were delivered to the muscle using supramaximal voltages. Subjects were treated with β‐blockade (2×80 mg oral propranolol, β‐b) or matched placebo in a double‐blind crossover design. Four different exercise conditions were studied: (I) maximal voluntary contraction (MVC); (II) MVC during circulatory occlusion; (III) electrical stimulation at 20 Hz using 50% of voltage required for maximal torque production; and (IV) electrical stimulation with occlusion. Each contraction was for 5 s with 5 s recovery. Total duration of exercise was 10 min for non‐occluded contractions and to a 50% decline in torque output with occlusion. At rest prior to exercise, maximal voluntary contraction was significantly reduced (5·7%) by β‐b during 40 observations in 16 subjects. Following exercise without occlusion (I and III), the reduction in torque output of the muscle at 10 and 20 Hz stimulation was generally greater during β‐b than placebo. This low frequency fatigue was longer‐lasting with β‐b. The shorter lasting reduction in torque at 50 and 100 Hz was generally not different between β‐b placebo. After exercise with occlusion (II and IV), the torque output at all stimulation frequencies was reduced to a similar extent in both placebo and β‐b at most comparison points. Twitch responses after exercise with occlusion showed decreases in peak tension and time to peak tension and a lengthening of one‐half relaxation time in both placebo and β‐b. It was concluded that the greater reduction in torque output of the triceps surae muscle group at low frequencies during β‐b was probably a consequence of a reduction in blood flow relative to the placebo treatment. This relative low frequency fatigue could be responsible for the increased perception of effort in patients exercising during β‐blocker therapy.
Carbohydrate utilization by exercising muscle following pre‐exercise glucose ingestion
Authors: Ahlborg G. , Björkman O.
Published: April 2008

Summary. The effect on exercising muscle metabolism of prior ingestion of 200 g glucose was examined in six healthy subjects during 40 min leg exercise at 30% of maximal oxygen uptake. Leg glucose uptake during exercise was on average two‐ to three‐fold higher after glucose (E+G) compared to exercise without glucose (E) and could account for 44–48% of the oxidative leg metabolism (control value: 19%, P<0·05‐0·01). In contrast to E, which was associated with a significant release of leg lactate, pyruvate and alanine, E+G gave no leg production of lactate or alanine and an uptake of pyruvate. The respiratory exchange ratios (R) were higher during G + E and corresponded to a carbohydrate oxidation of 54–69% as against 46–49% (P0<·05‐0·01) during E. Estimated from R‐values and leg oxygen and glucose uptakes, carbohydrate oxidation during G<E was almost completely accounted for by blood glucose. During E, on the other hand, carbohydrate oxidation exceeded leg glucose uptake, indicating a small but significant muscle glycogen breakdown (P<0·01). The rate of glycogen utilization during E or G + E was too small to be detected by direct measurements of muscle glycogen content. The results demonstrate that glucose ingestion prior to light exercise is followed by increased uptake and more efficient oxidation of glucose, as well as by insignificant muscle glycogen degradation by exercising muscle. Although the present findings suggest a glycogen‐conserving effect of glucose ingestion under these conditions, the main fuel shift is from fat to glucose oxidation.
Progressive central hypovolaemia in man—resulting in a vasovagal syncope?
Authors: Sander‐Jensen K. , Menken J. , Secher N. H. , Bach F. W. , Bie P. , Giese J. , Schwartz T. W. , Trap‐Jensen J. , Warberg J.
Published: April 2008

Summary. Hypotensive functional haemorrhage induced by venous pooling of blood in the legs has been reported to be characterized by a vasovagal reaction. In the present study these observations were extended by determination of the hormonal profile developed during progressive central hypovolaemia and an emotionally induced vasovagal syncope. In six subjects venous pooling resulted in normotensive central hypovolaemia, in one subject hypotensive central hypovolaemia was induced, and one subject experienced an emotionally induced vasovagal syncope.

During normotensive central hypovolaemia heart rate increased from 58 ± 4 to 76 ± 4 beats min‐1 (P<0·05) and cardiac output fell from 6·1 ± 0·4 to 4·1 ± 0·21 min‐1. Pulse pressure and central venous pressure decreased from 64 ± 4 to 53 ± 4 mmHg, and from 8 ± 2 to 3 ± 2 mmHg, respectively. Adrenalin and noradrenalin increased from 87 ± 10 to 120 ± 20 pg/ml and from 196 ± 33 to 370 ± 50 pg/ml, respectively. Angiotensin II increased from 13 ± 4 to 36 ± 6 pg/ml and aldosterone from 63 ± 9 to 180 ± 27 pg/ml.

In hypotensive central hypovolaemia the decrease in mean arterial pressure was accompanied by a decrease in heart rate and increments in the plasma concentrations of pancreatic polypeptide, indicating increased vagal activity and β‐endorphin, while plasma noradrenalin was unchanged.

In emotionally induced syncope heart rate decreased to cardiac arrest for 13 s, associated with increments in the plasma concentrations of pancreatic polypeptide and β‐endorphin.

It is concluded (1) that normotensive functional haemorrhage in man is associated with increased sympathetic activity and (2) that the qualitatively similar observations obtained during an emotionally and a hypovolaemic‐induced hypotensive episode indicate that the hypotensive functional haemorrhage is characterized by a vasovagal reaction.
ATP breakdown products in human skeletal muscle during prolonged exercise to exhaustion
Authors: Norman B. , Sollevi A. , Kaijser L. , Jansson E.
Published: April 2008

Summary. To study changes in muscle energy state during prolonged exercise, especially in relation to fatigue, muscle biopsies were obtained from seven healthy males working until exhaustion on a cycle ergometer at 68% (63–74%) of their maximal oxygen uptake. Biopsies were taken at rest, after 15 and 45 min of exercise and at exhaustion, and analysed for ATP, ADP, AMP, inosine monophosphate (IMP) and hypoxanthine content by high performance liquid chromatography (HPLC), and for creatine phosphate (CP), lactate and glycogen by enzymatic fluorometric techniques. Glycogen content at exhaustion was approximately 30% of the pre‐exercise level. The CP content decreased steeply during the first 15 min of exercise (P<0·01) and continued to decrease during the rest of the exercise period (P<0·05). Pronounced increases in contents of IMP (64%P<0·001) and hypoxanthine (69%, P<0·05) were found when exhaustion was approaching. Furthermore, energy charge [EC; (ATP+0·5 ADP)/(ATP+ADP+AMP)] was decreased at exhaustion (P<0·05). The increases in IMP and hypoxanthine which occurred when exhaustion was approaching during prolonged submaximal exercise together with the decrease in EC during this phase of exercise suggest a failure of the exercising skeletal muscle to regenerate ATP at exhaustion.
Atrial natriuretic peptide during acute treatment of congestive heart failure
Authors: Berglund H. , Bevegård S. , Carlens P. , Hedner J. , Hedner T.
Published: April 2008

Summary. Atrial natriuretic peptide (ANP) induces potent diuretic/natriuretic, vasorelaxing and aldosterone inhibitory effects. Increased plasma levels in congestive heart failure (CHF) have been reported. The aim of this study was to investigate plasma immunoreactive ANP (ir‐ANP) levels during acute treatment of CHF. Seven patients with CHF underwent cardiac catheterization. Ir‐ANP plasma levels were followed up to two h after administration of an orally given phosphodiesterase inhibitor (Milrinone); a substance with positive inotropic and peripheral vasodilating properties. In all patients cardiac output increased and cardiac filling pressures decreased markedly. Initially high ir‐ANP plasma levels decreased. Our patients did not have an increased blood volume.

It is concluded that plasma ir‐ANP levels in the pulmonary artery rapidly decrease when atrial pressure is reduced. These data suggest that atrial pressure is the major determinant for release of ir‐ANP in man and that the ability to respond quickly to changes in cardiac filling pressures is maintained in patients with severe CHF. Plasma ir‐ANP levels may also become useful as an index of the degree of heart failure and serve as a tool in monitoring response to drug therapy.
Physical working capacity determined by different types of bicycle exercise tests
Authors: Wallin L. , Brudin L. H.
Published: April 2008

Summary. Forty‐three pairs and 10 triplets of bicycle exercise tests were performed. Seven different workload incremental procedures were used. Triplets and nine pairs of tests were performed by healthy subjects (n= 19) and 34 pairs of tests by patients (n= 19) 3 and 15 months after coronary by‐pass operation. From each test result a hypothetical maximal workload sustainable for 6 min (Wmax6) was calculated. The two and three Wmax6. values obtained for each pair and each triplet of tests, respectively, were compared. The ratios between the corresponding Wmax6 values were 1·00 ± 0·01 (mean±SE) for healthy subjects and 0·96 ± 0·03 for patients. It is concluded that working capacities determined by bicycle exercise tests with different workload incremental procedures can be compared via the Wmax6.
Spirometry in healthy adult never‐smokers
Authors: Oxhøj H. , Jeppesen G. Mostgaard , Larsen V. Højkjær , Jørgensen B.
Published: April 2008

Summary. Spirometry was performed in 277 female and 240 male subjects constituting a random, unbiased population sample representative for the population of Denmark. Equipment, calibration and measurement procedures conformed strictly with established standards.

Statistical analysis showed that certain power transformations (cubic, quadratic or square root) of the data produced models that fitted the data statistically significantly better than linear models, where no transformations are applied, or logarithmic models where a logarithmic transformation is applied to the response variable. Differences between predictions obtained with the three models were, however, small and without practical significance.

Neither rigid adherence to established, well documented standards nor elaborate statistical analysis reduced the inter‐individual variance significantly in comparison to previous investigations.

The results emphasize that it is important that reference values are appropriate for the methods and population in question.
Coenzyme Q10 content in different parts of the normal human heart
Authors: Lin L. , Sotonyi P. , Somogyi E. , Karlsson J. , Folkers K. , Nara Y. , Sylvén C. , Kaijser L. , Jansson E.
Published: April 2008

Summary. Coenzyme Q10 (CoQ10) and citrate synthase (CS) activities were analysed in the myocardium of brain‐dead organ donors (14–40 years). Different parts of the heart were studied: right and left auricular appendage, right and left atrium, right ventricle (septum and free wall) and left ventricle (septum, free wall, and papillary muscle). Freeze‐dried, dissected myocardial samples were analysed for CoQ10 content by HPLC and CS activity by fluorometric technique. CoQ10 content in the normal human myocardium was lowest in auricular appendages and atria (0·25 ±0·06 mg×g‐1 dry muscle), intermediate in right ventricle (0·37±0·05 mg×g‐1 dm) and highest in left ventricle (0·42±0·07 mg×g‐1 dm). CS activity showed the same relationship between these locations as CoQ10. The results suggest that there exist differences in CoQ10 content between different parts of the normal human myocardium. These differences were closely related to the differences in CS activity between corresponding parts. The differences between different parts of the heart may be related to divergent work demand, and the constant relationship between CS and CoQ10 may be related to their coupling to the mitochondrial oxidative metabolism.
Effects of chronic dobutamine administration on the response to acute exercise in dogs
Authors: McKirnan M. D. , Stebbins C. L. , Longhurst J. C.
Published: April 2008

Summary. The effects of chronic dobutamine administration on haemodynamic and metabolic responses to submaximal and maximal exercise were studied in dogs. Dobutamine was infused at a rate of 40 μg/kg min‐1, 2 h day‐1, 5 days week‐1 for a period of 6 weeks. Acute infusion of dobutamine for 1 h increased heart rate by 73 ± 30 beats min‐1 and cardiac output by 143 ± 141 ml/min kg‐1, reduced mean arterial blood pressure by 12 ± 10 mmHg and arterial‐venous O2 difference by 1.5 ± 1 vol%. Maximal oxygen consumption, heart rate, stroke volume, cardiac output and arterial‐venous O2 difference were unchanged after 6 weeks of treatment. Reductions in heart rate at rest and during submaximal exercise following chronic dobutamine treatment were small and significant only at the lowest exercise level studied. Mixed venous lactate concentrations measured at rest, during submaximal and maximal exercise and at 2 min of recovery were not different after dobutamine treatment. Chronic dobutamine infusion did not change the citrate synthase activity in the lateral gastrocnemius muscle. These results suggest that chronic dobutamine therapy in healthy dogs does not produce aerobic training responses.
Influence of vibration on endurance of maximal isometric contraction
Authors: Samuelson B. , Jorfeldt L. , Ahlborg B.
Published: April 2008

Summary. In order to investigate how vibration affects endurance during muscular contraction, knee‐joint extension efforts were performed with and without superimposed vibrations. Fourteen healthy non‐smoking 20‐year‐old males performed maximal isometric and sustained knee‐joint extension efforts (angle 90°) in sitting posture three times with each leg, with or without vibration. The tests were done once with each leg in a randomly chosen order. The frequency of the vibration was 20 Hz and the acceleration 20 m/s2 RMS, applied in a horizontal sagittal direction to the ankle. The endurance was defined as the time in seconds that it took for the exerted force to decrease by 10% of the initial value.

The endurance time averages 22.5 s without vibration and 15.8 s with vibration. The vibratory stress reduced endurance by 6.7±1.84 s (mean ±SEM) (P<0.005). The difference in maximal force recorded initially was 34 ± 1.9 N (P<0.1). Our conclusion is that vibration may decrease the endurance of maximal och sustained isometric muscular contraction.
Pulmonary vascular resistance rises with lung volume on exercise in obstructed airflow disease
Authors: Schrijen F. V. , Henriquez A. , Carton D. , Delorme N. , Butler J.
Published: April 2008

Summary. There has been experimental evidence that lung distension produces an increase in pulmonary vascular resistance (PVR). To study this effect in patients, we measured functional residual capacity (FRC) by helium dilution at rest and during lowload supine exercise in 30 patients with chronic obstructive pulmonary disease. Pulmonary haemodynamics were studied in these patients under the same conditions.

FRC increased from rest (4·32 ± 0·21 1) to exercise (4·71 ± 0·20, P<0·001) but the change was smaller in the patients with the highest FRC at rest: there was a significant negative correlation between FRC change and FRC at rest (r=–0·38, P<0·01). There were seven patients with a small FRC change (<0·2 1) with exercise and 10 patients with a marked increase (>0.5 1). Exercise was of the same load on average. FRC at rest was 5·1 1 in the first group and 4 1 in the second (P<0·05). Blood gases were almost identical at rest, and almost unchanged during exercise. PVR decreased from rest to exercise by 33 dyn.s.cm‐5 in the first group and increased by 24 in the second (P<0·01). There was a significant correlation (P<0·05) between PVR and FRC changes from rest to exercise. These results suggest that lung distension may play a role in the PVR increase seen in some COPD patients with exercise.
Nitrogen dead space in heavy smokers aged 44–58 years
Authors: Rosberg H. E. , Wiberg R. , Arborelius M.
Published: April 2008

Summary. Functional and alveolar dead spaces for nitrogen (Vdf and Vdalv) were calculated in a population of 20 male and 20 female heavy smokers and compared to data from static and forced spirometry (functional residual capacity [FRC], residual volume [RV], lung clearance index [LCI] and volume of trapped gas [VTG]) obtained with the same multiple‐breath nitrogen wash‐out as the dead spaces, and to variables considered sensitive to small airways disease measured with a single‐breath nitrogen elimination (closing volume in per cent of vital capacity [CV%], closing capacity in per cent of total lung capacity [CC%] and slope index [SI]).

Both nitrogen dead spaces increased with tidal volume in smokers as well as in healthy non‐smokers. The majority of smokers were outside the predicted mean+2 SD for VTG (75%), CC and VDalv (70%) and SI (65%). The following variables were less sensitive for disclosing abnormality: CV (55%), RV (53%), LCI (38%) and forced expired volume in the first second (FEV1, 33%). If high sensitivity is considered preferable in epidemiological studies, the nitrogen dead spaces are equally as sensitive as the better of earlier described tests, and significantly superior to LCI and FEV1. Being tests that measure alveolar distribution of inhaled gas, they are probably sensitive to small airways disease.
Testing of autonomic cardiovascular regulation—methodological considerations
Authors: Mustonen J. , Länsimies E. , Uusitupa M. , Talwar S. , Hyödynmaa S. , Kärkkäinen A.
Published: April 2008

Summary. The different analyses of the results on autonomic nervous function tests were evaluated in 43 male and 32 female diabetic patients and in 24 male and 24 female control subjects, aged 47–67 years, all without any known heart disease. The Valsalva ratio of the first effort did not differ from the mean Valsalva ratio of three efforts. During deep breathing, heart rate variation and max/min R‐R interval ratio determined from the first three breathing cycles did not differ from the respective variables calculated from six consecutive breathing cycles. Diastolic blood pressure response to isometric handgrip was greater during the third minute than during the first and the first two minutes. In conclusion, the tests for the evaluation of autonomic nervous function can be simplified without losing their diagnostic value.
Impaired responses of plasma catecholamines to exercise in diabetic patients with abnormal heart rate reactions to tilt
Authors: Bergström B. , Manhem P. , Bramnert M. , Lilja B. , Sundkvist G.
Published: April 2008

Summary. The plasma catecholamine response to a standardized bicycle exercise test was evaluated in 24 insulin‐dependent diabetic (IDDM) patients in whom the heart rate reactions to deep breathing (E/I ratio) and to tilt, the immediate acceleration and the transient deceleration (acceleration and brake indices), had been assessed as tests of autonomic neuropathy. Patients with an abnormal acceleration index (n= 8) showed, compared with non‐diabetic (n= 18) controls who had participated in previous studies, an impaired increment in noradrenaline during exercise (80% of maximal working capacity) (MWC) (12·38 ± 1·46 nmol l‐1 vs. 18·74 ± 1·45 nmol I‐1; P<0·01) and adrenaline (50% of MWC: 0·25 ± 0·04 nmol I‐1 vs. 0·54 ± 0·08 nmol II–1; P<0·05). Similarly, patients with an isolated abnormal brake index (n= 6), i.e. with a normal acceleration index and a normal E/I ratio, showed compared with controls an impaired increment in noradrenaline (9·53 ± 1·66 nmol I‐1 vs. 18·74 ± 1·45 nmol I‐1; P<0·01) and adrenaline (1·41 ± 0·22 nmol I‐1 vs. 2·92 ± 0·51 nmol I‐1; P<0·05) during 80% of MWC. IDDM patients with abnormal heart rate reactions to tilt, an abnormal acceleration index or an abnormal brake index show impaired catecholamine responses to exercise, which can be demonstrated also in patients without signs of parasympathetic neuropathy.
Diet‐induced thermogenesis in well‐trained subjects
Authors: Thörne A. , Wahren J.
Published: April 2008

Summary. The purpose of this study was to examine the possible relationship between the thermogenic response to a mixed meal and the aerobic capacity in healthy subjects. Fourteen male subjects participated, and their maximal oxygen uptake was determined on a bicycle exercise ergometer. Two groups, each comprising seven individuals, were compared: a well‐trained group, with an oxygen uptake of 58·2 ml min ‐1 kg‐1 and a sedentary group, with an oxygen uptake of 39·2 ml min‐1 kg‐1. Respiratory gas exchange was measured continuously for 1 h in the basal state and then for 3 h postprandially. The subjects ingested a test meal in liquid form, consisting of 17% kJ protein, 28% kJ lipids and 55% kJ carbohydrates, and corresponding to 60% of the individually computed 24‐h basal energy expenditure. Basal oxygen uptake and energy expenditure were similar in the two groups. After the meal, pulmonary oxygen uptake and energy expenditure rose rapidly and reached a plateau after 1 h. The responses were no different in the two groups: the average rise in pulmonary oxygen uptake above basal during the whole study period was 24.0±2.1% in well‐trained and 26.7±1.5% in sedentary subjects (NS); the corresponding values for energy expenditure were 25.0±2.1% and 29.0±1.6% (NS). Also, when expressed in absolute terms the increments above basal were not significantly different. There was no discernible relationship between the individual thermogenic response and maximal oxygen uptake. In conclusion, the present findings do not indicate that diet‐induced thermogenesis is proportional to aerobic capacity in healthy young men.
Vasodilatation in human skin induced by low‐amplitude high‐frequency vibration
Authors: Skoglund C. R.
Published: April 2008

Summary. Vasomotor effects in human skin induced by vibration of low amplitude (10–25 μm) and high frequency (150–250 Hz) have been studied by using skin temperature changes as an approximative measure of variations in skin blood flow. In all tested areas of the body surface, including the face, low‐amplitude high‐frequency vibration regularly induces vasodilatation. The spatial distribution of the temperature changes induced from different sites of stimulation was studied by infrared thermography. The latencies of the temperature changes, determined by thermistor recordings, were found to vary with site of stimulation and stimulus parameters. The increase in temperature to a given stimulus is greater the lower the prevalent skin temperature, i.e. the increase in blood flow is larger the greater the initial vasomotor tone. The results are in accordance with the view that the vasodilatation is due to a reflex inhibition of pre‐existent vasomotor tone in the skin by the afferent inflow from vibration‐sensitive mechanoreceptors. High‐amplitude vibration (100–200 μm), performed in a few comparative experiments, caused vasoconstriction.
Cardiovascular and metabolic response to adrenaline infusion in weight‐losing patients with and without cancer
Authors: Drott C. , Persson H. , Lundholm K.
Published: April 2008

Summary. Fasting is generally accompanied by a decrease in energy metabolism and hormones. On the other hand, indirect evidence has suggested that the response to adrenergic agonists may be maintained or even increased in malnutrition. The present study evaluated whether weight‐losing patients with and without cancer have increased plasma concentrations of catecholamines and different responses to intravenously infused adrenaline compared to weight‐stable individuals. Eight malnourished cancer and 10 non‐cancer patients (11% weight loss) were compared to seven well‐nourished and weight‐stable patients. Adrenaline was infused i.v. at a rate of 0·005 μg min‐1 kg‐1 body weight during 40 min followed by a 40 min rest period (without infusion) and then a final 40 min period with i.v. adrenaline infusion (0·02 μg min‐1 kg‐1 body weight).

Plasma glycerol concentration at fast was higher in weight‐losing patients compared to weight‐stable individuals. Whole body oxygen uptake, carbon dioxide production, heart rate and plasma concentrations of free fatty acids (FFA) increased while the mean arterial pressure decreased significantly in response to adrenaline infusion at 0·02 μg kg‐1 min‐1 in both weight‐losing and weight‐stable patients. Adrenaline at 0·005 μg kg‐1 min‐1 increased plasma FFA levels by 19% (P<0·05) in weight‐losing patients while no significant alteration was observed in well‐nourished patients. Adrenaline infusion at 0·02 μg kg‐1 min‐1 decreased the mean arterial blood pressure and stimulated respiratory gas exchange and heart rate significantly more in weight‐losing than in weight‐stable patients. The slopes for oxygen uptake, carbon dioxide production, heart rate, plasma FFA and plasma glycerol vs. plasma adrenaline and noradrenaline were all significantly steeper (P<0·05–0·01) in malnourished patients than in well‐nourished controls.

The present study suggests an increased sensitivity to adrenaline in weight‐losing patients compared to matched controls with normal nutritional state and stable weight.
Effects of prolonged adrenaline infusion and of mental stress on plasma minerals and parathyroid hormone
Authors: Joborn H. , Hjemdahl P. , Larsson P.‐T. , Lithell H. , Olsson G. , Wide L. , Bergstrom R. , Ljunghall S.
Published: April 2008

Summary. The role of the sympatho‐adrenal system for the secretion of PTH in humans is not established. Previous studies on the effects of adrenaline on plasma mineral homeostasis have focused on injections or short‐term infusions of adrenaline, and conflicting results concerning calcium and parathyroid hormone (PTH) responses have been reported. We therefore infused adrenaline or placebo continuously for 3 h to 10 healthy volunteers and studied several plasma minerals, as well as PTH levels. Venous plasma adrenaline concentrations increased to the upper physiological range (5 nmol l‐1) during adrenaline infusion. Another nine volunteers were exposed for 25 min to mental stress (a colour word conflict test; CWT), which causes marked circulatory changes and raises plasma catecholamine concentrations. Plasma ionized and total calcium, and magnesium concentrations were slowly and gradually reduced during infusion of adrenaline, but there was only a small increase in PTH. Plasma potassium was decreased by adrenaline within 30 min and thereafter did not change further during infusion. There was a marked but transient increase in the plasma free fatty acids concentrations, which were not related to the reduction of the calcium or magnesium levels. The adrenaline‐induced decrements in calcium, magnesium and potassium, and increases in heart rates persisted 30 min after the infusion, despite a rapid decrease in plasma adrenaline concentrations within 5 min of termination of the infusion. Plasma phosphate concentrations were lowered during the first 90 min of adrenaline infusion, but after 3 h they had returned to baseline despite continued infusion. CWT induced small increments of the plasma ionized calcium and PTH concentrations. Plasma potassium levels were raised despite increases in plasma adrenaline at the beginning of the stress test, while phosphate values were reduced at the end of the test. Thus, long‐lasting elevations of circulating adrenaline lower plasma ionized and total calcium, phosphate, magnesium and potassium, but the time courses for these changes differed markedly. Despite the reduction of plasma ionized calcium there was only little increase in PTH and thus no indication that sustained elevations of circulating adrenaline stimulates the secretion of PTH in vivo in humans. Responses to acute mental stress and adrenaline infusion differed qualitatively, indicating that adrenaline responses to stress are of minor importance in this respect.
Plasma lipid and lipoprotein profiles in pre‐ and post‐menopausal middle‐aged runners
Authors: Higuchi M. , Iwaoka K. , Ishii K. , Matsuo S. , Kobayashi S. , Tamai T. , Takai H. , Nakai T.
Published: April 2008

Summary. Plasma lipid and lipoprotein profiles were compared in middle‐aged trained and untrained women before and after menopause. Subjects were assigned to one of four groups:

(1) pre‐menopausal trained (Pre‐T: n= 17, aged 42 ±5 years, body fat 19±5%, training distance 53 ±20 km week‐1, V̇o2max 49 ±4 ml kg‐1 min‐1, mean±SD);

(2) pre‐menopausal untrained (Pre‐UT: n= 26, 42 ±5 years, 24 ±7%, 34 ±6 ml kg‐1 min‐1);

(3) post‐menopausal trained (Post‐T: n= 16, 54 ±3 years, 20 ±4%, 43 ±19 km week‐1, 41 ±5 ml kg‐1 min‐1); and

(4) post‐menopausal untrained (Post‐UT: n= 15, 55 ±3 years, 25 ±6%, 31 ±3 ml kg‐1 min‐1).

There were no significant differences in total cholesterol (range 173–194 mg dl‐1), triglyceride (56–72 mg dl‐1), and HDL‐cholesterol (HDLC: 76–85 mg dl‐1) among the four groups. LDL‐cholesterol (LDLC) in the post‐menopausal women (Post‐T: 96 ±32 mg dl‐1; Post‐UT: 104 ±23 mg dl‐1) tended to be higher than in the premenopausal women (Pre‐T: 86 ± 25 mg dl‐1, Pre‐UT: 81 ± 23 mg dl‐1). LDLC/HDLC ratio in Post‐UT (1·42 ±0·38 unit) was higher than in the pre‐menopausal women (Pre‐T: 1·03±0·31 unit, P<0·01; Pre‐UT: 1·10±0·38 unit, P<0·05), whereas the ratio in Post‐T (1·20 ±0·38 unit) was not different from those of the pre‐menopausal groups. These results suggest that endurance running protects against the increase in LDLC/HDLC ratio that frequently occurs after menopause.
The venous pump of the human foot
Authors: Styf J.
Published: April 2008

Summary. Pressures in the flexor digitorum muscle, posterior tibial and anterior tibial muscles and subcutaneous pressure in the lower leg were recorded in 18 volunteers with a non‐infusion technique. The venous plexus of the sole of the foot was compressed by a pneumatic foot pump. Activation of this device creates oscillations of intramuscular and subcutaneous interstitial fluid hydrostatic pressure in the lower leg. The mechanism for this is explained by intermittent passive muscle stretch. The interstitial fluid pressure decreased following active muscle contractions during venous stasis of the limb, but not following activation of the pneumatic pump. Although the pneumatic foot pump may on theoretical grounds be useful in early treatment of postoperative and post‐traumatic oedema of the leg, complementary studies are necessary to establish its effectiveness.
Clinical physiology: an accepted branch of physiology
Authors: Linderholm H.
Published: April 2008

Summary. Clinical physiology is a branch of physiology particularly dealing with functional disturbances in disease (pathophysiology) and the integrated function of the human body in disease against the background of normal function in healthy subjects, suitable physiological methods for the study of patients — particularly for diagnostic purposes — as well as for research, and the education of medical students and laboratory assistants in these fields. Departments of clinical physiology in university hospitals form a bridge between basic physiology and many clinical specialities.

Independent departments of clinical physiology developed early in Sweden due to the work of Professor Torgny Sjöstrand at the Karolinska Hospital in Stockholm, and have been models of research, teaching and hospital organization which have been followed in several other countries.

The International Union of Physiological Sciences (IUPS) has recognized clinical physiology as a separate branch of physiology by approving a Commission of Clinical Physiology which has contributed to the programme of this and, we hope, future congresses, as well as promote the development of clinical physiology internationally.
Pulmonary absorption of instilled and inhaled DTPA in smokers
Authors: Groth S. , Kristjansen P. E. G. , Mortensen J. , Merrild D.
Published: April 2008

Summary. Pulmonary absorption of DTPA (diamine‐triethylene‐penta‐acetic acid) has been widely adopted as an index of pulmonary epithelial permeability. The aim of this study was to analyse:

 if measurements of pulmonary absorption are influenced by the amount of fluid being administered to the lungs together with the DTPA; and

 if all DTPA administered to the lungs is equally accessible for pulmonary absorption.

To this end DTPA was instilled into a lung segment of six smokers in association with a bronchoscopy. In six other subjects (five smokers and one ex‐smoker) the DTPA was inhaled as an aerosol. Pulmonary absorption of DTPA was calculated from the plasma DTPA content, as determined for 4–10 h after the administration of the DTPA. We found that the mean transit time for the absorption of instilled DTPA, i(L), across the pulmonary membranes was significantly (P<0·05) longer (median 1498 min, range 955–2636 min) than the fi(L) of the absorption of the inhaled DTPA (median 131 min, range 44–512 min). Pulmonary clearance of the inhaled aerosolized DTPA tended to be faster when determined by external detection for 4 h, than when estimated from plasma samples, suggesting that not all pulmonary DTPA may be equally accessible for absorption from the pulmonary lining fluids. We conclude that pulmonary absorption of DTPA is influenced by the volume of fluid being administered to the lungs in association with the measurements. Not all pulmonary DTPA, however, is equally accessible for absorption, rendering external detection of pulmonary clearance of DTPA sensitive to a variety of factors other than pulmonary absorption.