bluuebunny/crossref_metadata_2025 huggingface dataset:
Cardiac output determined by ultrasound‐Doppler: clinical applications
Authors: Sjöberg B. Janerot , Wranne B.
Published: April 2008

Summary. A non‐invasive method for cardiac output determination (COD) based on ultrasound‐Doppler technique was evaluated in patients with cardiac disease at rest and during exercise, including patients with heart transplants. The aortic blood flow velocity was measured with pulsed Doppler technique from the jugulum, placing the sample volume just above the aortic valve, and the area from a parasternal 2‐D echocardiographic measurement of the aortic annulus diameter assuming a circular area. Cardiac output was calculated as the product of the systolic velocity integral, the aortic annulus area and the heart rate. A high correlation was found between this method and a simultaneously performed invasive cardiac output (COF) and stroke volume (SVF) determination by the direct Fick method (COD = 0.3+0.9 x COF, r= 0.96, SDres= 0.5 1 min‐1 and SVD = 3.9+0.92 × SVF, r= 0.94, SDres= 6.9 ml). However, looking just at the systolic velocity integral compared to stroke index determined with the Fick method we found a low correlation, especially in patients with heart transplants.

We conclude that cardiac output can reliably be measured non‐invasively with this method—also in patients with heart transplants. The systolic velocity integral alone can be used for assessing changes in stroke volume but for absolute values of stroke volume and stroke index flow area should also be determined.
Histochemical demonstration of skeletal muscle fibre types and capillaries on the same transverse section
Authors: Hather B. M. , Mason C. E. , Dudley G. A.
Published: April 2008

Summary. Serial transverse sections of m. vastus lateralis biopsies from six healthy men were reacted:

 for myofibrillar adenosine triphosphatase (mATPase) to identify fibre types;

 with α‐amylase, periodic acid‐Schiff (αPAS) to visualize capillaries. Sections were also processed with a new histochemical method for identification of fibre types and capillaries on the same skeletal muscle slice (mATPase/αPAS). Fibre type composition using either method was 41% type I, 37% type IIA and 22% type IIB. Types I, HA and IIB least diameter areas (mean±SE, μm2) were similar in sections processed for mATPase/αPAS or mATPase (3976±338, 5187±373 and 4389±514 vs. 4092±345, 5100±360 and 4289±474, respectively). The number of capillaries per mm2 and per fibre did not differ in sections processed using the αPAS (315±29 and 1·48 ±0·12) or mATPase/αPAS (317±25 and 1·43±0·10) method. The number of capillaries was greater (P<0·05) around types I or IIA than type IIB fibres whether a section was processed for mATPase/αPAS (4·5±0·2 or 4·6±0·2 vs. 3·4±0·3) or when fibre profiles of serial sections reacted for mATPase or αPAS were ‘matched’ (4·5±0·2 or 4·4±0·2 vs. 3·4±0·3). The results indicate that histochemical and morphometric measures can be made on the same transverse section using the new method with substantial savings of time, cost and energy.
The effect of cooling on toe systolic pressures in subjects with and without Raynaud's syndrome in the lower extremities
Authors: Carter S. A.
Published: April 2008

Summary. The effect of changes in local and body temperature on the toe systolic pressures was studied in 20 subjects with and 30 without Raynaud's syndrome in the toes. The pressures were significantly lower in the group with Raynaud's syndrome under all experimental conditions (P < 0·01). The pressures were significantly lower during body cooling than during body warming in both groups (P < 0·01). The mean decrease with body cooling was 58 mmHg in the group with Raynaud's syndrome and 24 mmHg in the control subjects (P < 0·01). During body cooling pressures fell to less than 30 mmHg in 70% of subjects with Raynaud's syndrome and in 3% of the controls. Local cooling from 30 to 10°C during body cooling resulted in a significant mean decrease in pressure of over 40 mmHg in both groups (P < 0·01) and the pressure fell below 30 mmHg in over 90% of the group with and in 26% of those without Raynaud's attacks.

The results indicate the importance of body cooling and local temperature in the mechanism of vasospasm in the toes. They are also relevant to the diagnosis of Raynaud's syndrome in the lower limbs and have implications for the testing of patients with arteriosclerotic occlusion since erroneously low pressure values could be obtained in tests when the feet are cold.
Effects of Vacusac in intermittent claudication: a controlled cross‐over study
Authors: Himmelstrup H. , Himmelstrup B. , Mehlsen J. , Trap‐Jensen J.
Published: April 2008

Summary. The effect of a new physical treatment modality, Vacusac, was tested on a group of patients with stable intermittent claudication.

Twenty‐two patients with a median age of 65 years and a median duration of intermittent claudication of 5 years were randomized to either active or placebo treatments. Seventeen patients completed the study. The effect of treatment was quantified by measurements of systemic ‐and peripheral systolic blood pressures and by measurements of the pain‐free and the maximal walking distance on a treadmill. The ankle pressure index (ankle systolic pressure/arm systolic pressure) and toe pressure index (toe systolic pressure/arm systolic pressure) were calculated.

After 25 active treatments, administered over a period of 2 months, the patients allocated to this group attained a significant increase in the pain‐free walking distance from 54 m (24–107 m) to 99 m (30–420 m) (P < 0·05) and in the maximal walking distance from 99 m (36–182 m) to 185 m (68–591 m) (P < 0·05). The patient group receiving 25 placebo treatments did not show any significant changes in either the pain‐free or the maximal walking distance. This group then received 25 active treatments over a period of 2 months. This active treatment resulted in a significant increase in the pain‐free walking distance from 51 m (14–100 m) to 86 m (18–1000 m) (P < 0·05) and in the maximal walking distance from 98 m (40–199 m) to 175 m (51–1000 m) (P < 0·05). Ten out of the 17 patients who completed the study achieved a doubling of their maximal walking distance. The patients randomized to active treatment attained a significant increase in the ankle pressure index from 0–46 (0–39‐0·67) to 0·58 (0·46‐0·94) (P < 0·05) while the toe pressure index was unchanged. The patients randomized to placebo treatment did not show any significant changes in these ratios, either during the period of placebo treatment, or during the period of active treatment.

In conclusion, our study has shown that physical treatment with the Vacusac equipment significantly increases the walking distance in patients with stable, intermittent claudication of long duration.
Renal and systemic plasma immunoreactive neuropeptide Y and calcitonin gene‐related peptide responses to mental stress and adrenaline in humans
Authors: Tidgren B. , Theodorsson E. , Hjemdahl P.
Published: April 2008

Summary. Arterial plasma levels and renal venous overflows of immunoreactive neuropeptide Y (NPY‐LI) and calcitonin gene‐related peptide (CGRP‐LI) were studied during mental stress (a modified version of Stroop's colour word conflict test–CWT) and during i. v. infusions of step‐wisely increasing doses of adrenaline (ADR) in 12 healthy male volunteers. At rest, mean arterial plasma levels of NPY‐LI and CGRP‐LI were 27±2 pmol 1‐1 and 61±9 pmol I‐1, respectively. No renal venoarterial concentration difference could be demonstrated for either peptide at rest. Although CWT caused a three‐fold increase in the simultaneously measured renal venous overflow of noradrenaline, indicating markedly increased renal sympathetic nerve activity, the arterial levels of NPY‐LI were unchanged and the net renal overflow of NPY‐LI was only slightly (not significant) and transiently increased. CWT also failed to influence CGRP‐LI levels in arterial plasma or CGRP overflow from the kidney. During ADR infusions, which increased arterial plasma ADR from 0.25±0.06 to 6.43±0.27 nmol I‐1, NPY‐LI levels were unaffected but CGRP‐LI levels in arterial plasma were elevated (P<0.001 by ANOVA). No net renal overflow of CGRP‐LI could, however, be demonstrated. These findings suggest that CWT is not powerful enough a stimulus to significantly enhance systemic or renal overflows of NPY‐LI even though marked renal sympathetic activation occurs. During ADR infusions plasma CGRP‐LI levels increased but renal veno‐arterial differences of CGRP‐LI were unaltered, indicating that CGRP‐LI may be released from sites other than the kidney by ADR.
Serum creatine kinase activity and its changes after a muscle biopsy
Authors: Hikida R. S. , Staron R. S. , Hagerman F. C. , Leonardi M. , Gilders R. , Falkel J. , Murray T. , Appell K.
Published: April 2008

Summary. The significance of the absolute elevations of serum creatine kinase (CK) levels after intense exercise and injuries was studied by measuring CK activities from seven healthy active males during a 2‐week period, with a muscle biopsy taken between the first and second week. Most of the subjects (three lifters and two runners) carried on their normal exercise activities, while two lifters stopped training during the 2 weeks. The weight of the biopsy, number of fibres, percentage of fibre types, and cross‐sectional areas of the muscle fibres were measured. The CK levels of the nonactive subjects and runners remained consistently low during the control week, whereas those of the lifters were usually 500% greater than those of the other two groups, and fluctuated with the intensity of their workouts. A muscle biopsy, having a mean weight of 71.3 mg and containing 1800 fibres, increased the CK values by approximately 100 units litre‐1 (U1‐1) in most of the subjects. One runner injured his right hamstring muscles 2 days prior to the biopsy, and his CK values rose from 50 to 4400 U I‐1. The increases in CK after the biopsy were not related to fibre type, activity, weight of the biopsy, or number or size of fibres removed. These results indicate that:

CK values are consistently lower in normal subjects and runners than in lifters.

Weight training results in chronic elevations of CK.

Compared to a muscle biopsy, muscular injury dramatically increases CK levels.

Elevation of serum CK is observed as early as 1 h after an intense weight‐lifting session.

The elevation of serum CK by 100 U 1‐1 is associated with damage to approximately 2000 fibres.
Splanchnic release of neuropeptide Y during prolonged exercise with and without β‐adrenoceptor blockade in healthy man
Authors: Ahlborg G. , Lundberg J. M.
Published: April 2008

Summary. Plasma levels of neuropeptide Y‐ (NPY‐) like immunoreactivity (Li) and catecholamines in the brachial artery, femoral vein and hepatic vein were monitored during physical exercise in a total of 19 healthy men to detect any local release from the leg and splanchnic region. In addition, propranolol (0·15 mg kg1 i.v.) was given during exercise to determine whether P‐adrenoceptor blockade influenced the increase in plasma NPY‐Li and catecholamines. Leg and splanchnic blood flows were measured using indicator dilution techniques and indocyanine green dye. Graded arm exercise was associated with elevations of arterial plasma NPY‐Li (two‐fold) and noradrenaline (12‐fold) comparable to those previously found during leg exercise. During prolonged leg exercise a significant vasoconstriction and release of NPY‐Li and noradrenaline was observed in the splanchnic region while no net exchange was found in the exercising leg where marked vasodilatation occurred. Administration of propranolol during exercise produced a clear‐cut additional increase in plasma NPY‐Li as well as in noradrenaline and adrenaline. It is concluded that splanchnic vasoconstriction during exercise is associated with a local release of both NPY‐Li and noradrenaline. The additional elevation in plasma NPY‐Li and catecholamines after propranolol during exercise is probably due to increased nerve activity and/or decreased disposal.
Ambulatory measurement of nocturnal fluctuations in subcutaneous blood flow rate in the lower leg of man during 12‐h periods with the portable CdTe(C1) detector. Methodological considerations
Authors: Sindrup J. H. , Kastrup J. , Jørgensen B. , Bülow J. , Tønnesen K. H.
Published: April 2008

Summary. Possible sources of error during long‐term measurements of subcutaneous blood flow rate with the portable CdTe(Cl) detector system were ruled out in the present study. Local blood flow rates were recorded in the lower legs of normal human subjects by means of the 133Xe wash‐out technique. A good correlation was found between the portable CdTe(Cl) and stationary NaI(Tl) detector systems both prior to (r = 0·88, P<0·0001) and after (r = 0·68, P = 0·07) day over night (12 h) measurements. Identical post‐ischaemic reactive hyperaemia could be demonstrated by both detector systems 12 h after the application of the isotope depot. This indicates that blood flow rates and vascular reactivity can be measured over 12 h by the portable CdTe(Cl) detector. Identical results were obtained during the 12‐h measurements performed with the portable CdTe(Cl) detector attached directly to the skin surface and with the detector elevated above the skin surface. Therefore, geometrical changes were without any influence on our measurements. We conclude that measurements of subcutaneous blood flow rates in the lower leg of human subjects can be performed under out‐patients conditions by means of the 133Xe wash‐out technique and portable CdTe(Cl) detectors. A skin area≥4 cm should be labelled by means of the atraumatic, epicutaneous labelling technique and the detector attached directly to the skin surface with a single layer of a 20‐μm thick gas‐tight Mylar membrane interposed between the skin surface and the detector. The investigation of the subcutaneous blood flow rate should not be initiated until at least 90 min after labelling. Measurements over depots emitting < 1000 counts per sampling period should be avoided unless background activity is subtracted.
Skin perfusion patterns (fluorescein perfusography) during reactive hyperaemia in peripheral arterial occlusive disease
Authors: Scheffler A. , Bold M. , Lienke U. , Rieger H.
Published: April 2008

From the pathophysiological point of view the regional distribution of blood flow is of special importance in ischaemic tissues. Within this study foot sole skin perfusion was investigated by means of fluorescein perfusography at rest and during reactive hyperaemia in patients with peripheral arterial occlusive disease confined to one limb (Fontaine stage 11). Ambient temperatures were maintained around 21°C. Mean fluorescein appearance times on the one side and their standard deviations (SD) and coefficients of variation (CV) on the other side were taken as measures of overall blood supply and homogeneity of flow, respectively. At rest no differences in these parameters could be detected between diseased legs and controls. After a 3‐min supra‐systolic circulatory arrest at the thigh, a significant reduction of fluorescein appearance times was observed for both groups but was statistically more pronounced in the controls. Furthermore, during reactive hyperaemia standard deviations as well as coefficients of variation decreased significantly only in normal limbs whereas they either remained constant (SD) or even increased (CV) in those with arterial obstructions. All effects associated with reactive hyperaemia showed statistically significant correlations with systolic ankle pressure indices. From these results it is concluded that haemodynamically effective arterial obstructions are followed by not only a restriction of overall hyperaemic blood supply but also a failure to homogenize microcirculatory perfusion in the case of increased flow requirements.
Plasma lipid and lipoprotein profile in elderly female runners
Authors: Higuchi M. , Oishi K. , Ishii K. , Iwaoka K. , Matsuo S. , Kobayashi S. , Tamai T. , Takai H. , Nakai T.
Published: April 2008

Plasma lipid and lipoprotein profiles were compared in elderly female runners (RU: n= 15, aged 66 ± 5 years, body fat 20 ± 4%, training distance 35 ± 15 km week1, V̇O2max 36 ± 4 ml kg1 min1, mean ± SD) and age‐matched untrained women (UT: n= 28, 66 ± 4 years, body fat 26 ± 6%, V̇O2max 26 ± 3 ml kg1 min1). There were insignificant differences in total cholesterol (RU: 5·04 ± 0·60 vs. UT: 5·48 ± 0·85 mmol 11), HDL‐cholesterol (RU: 1·97 ± 0·41 vs. UT: 1·91 ± 0·36 mmol 11) and LDL‐cholesterol (RU: 2·72 ± 0·59 vs. UT: 3·03 ± 0·80 mmol 11) between the two groups. Plasma triglyceride concentration of the runners was significantly lower than that of the untrained women (RU: 0·80 ± 0·27 vs UT: 1·14 ± 0·36 mmol 11, P < 0·01). No difference was observed in the LDL‐cholesterol/HDL‐cholesterol ratio between the two groups (RU: 1·45 ± 0·51 vs UT: 1·64 ± 0·53 units). These results suggest that regularly performed running of 35 km week1 in elderly women does not further elevate their HDL‐cholesterol level which is already high compared to the levels found in elderly men. However, elderly female runners appear to be protected against age‐related increases in the levels of triglyceride and LDL‐cholesterol.
Acute intracranial hypertension and basilar artery blood flow velocity recorded by transcranial Doppler sonography: an experimental study in rabbits
Authors: de Bray J. M. , Saumet J. L. , Berson M. , Lefteheriotis G. , Pourcelot L.
Published: April 2008

Summary. The relationship between intracranial hypertension and basilar artery blood flow is not well known, and it is not yet definite that the reduction of cerebral flow depends on cerebral perfusion pressure rather than microvessel compression. The purpose of the study described here was to investigate the effect of acute intracranial pressure on the basilar flow velocity, the cerebral perfusion pressure, and the systemic arterial pressure. The basilar Doppler signal was recorded continuously in 24 New Zealand rabbits by transcranial pulsed Doppler method. The acute intracranial hypertension was induced by the progressive raising, in steps of 5 mmHg, of a saline infusion bottle connected to an epidural sensor. The intracranial hypertension induced a decrease in diastolic and mean flow velocities in the basilar artery, and an increase in the resistance index. Cerebral perfusion pressure was significantly correlated with flow parameters. The basilar diastolic flow began to decrease significantly from a 35–40 mmHg intracranial pressure and for a 37 mmHg+20 SD cerebral perfusion pressure, without significant variation of arterial pressure. Diastolic flow dropped to zero for a 53 mmHg intracranial pressure and a 30 mmHg+15 SD cerebral perfusion pressure. These results show that high intracranial pressure values are necessary for significantly reducing basilar artery blood flow. This effect, and the increase of circulatory cerebral resistance, occurred before significant changes in systemic arterial pressure.,
Muscular strength in idiopathic haemihypertrophy
Authors: Maffulli N. , Fixsen J. A. , Jackson A. M.
Published: April 2008

Summary. Nine patients (age 8.9, range 6.5 to 9.5 years) with idiopathic haemihypertrophy were followed at six month intervals for two years. The isometric voluntary contraction strength of the elbow flexors and knee extensors was measured bilaterally, and expressed per unit of muscle and bone cross sectional area of the upper arm (elbow flexors) and of the mid thigh (knee extensors). In absolute terms, the hypertrophic side was always stronger, and the increase in strength was strongly correlated with the increase in limb size bilaterally (P<0.01). The hypertrophic limb always exerted greater isometric strength, but if strength was standardized for an anthropometric estimate of upper arm and mid thigh cross sectional area, the normal and hypertrophic side were not significantly different. The limb length discrepancy, when expressed in percentage, remained constant at approximately 3%.
Non‐invasive vs. invasive beat‐to‐beat monitoring of blood pressure
Authors: Gabriel A. , Lindblad L. E. , Angleryd C.
Published: April 2008

Summary. The present study focuses on the accuracy in tracing fast beat‐to‐beat changes in blood pressure using a non‐invasive technique. The measurements using a commercially available apparatus (Finapres, Ohmeda, USA) were compared to ipsilateral intra‐arterial radial pressure. Eight patients were studied at rest, during deep breathing with a fixed rate of 6 breaths min‐1, and during an exercise test on an ergometer cycle. A total of 900 systolic pressure values were included for statistical evaluation, covering a pressure range of 86–266 mmHg. On average the systolic correlation coefficient for the whole material was 0.97, with a range of 0.94–0.996. For mean pressure the correlation coefficient was on average 0.97, and for diastolic pressure 0.93. No systematic difference between the non‐invasive and the invasive method was found, although for each individual patient a difference between direct and indirect measured blood pressure existed that could be relatively large (systolic pressure: average difference = 0.8 mmHg, SD = 16 mmHg). We found the method easy to handle and consider it excellently suited to track relative changes in blood pressure.
Pulmonary clearance of 99mTc–DTPA and 99mTc‐albumin in rabbits with surfactant dysfunction and lung injury
Authors: Nilsson K. , Wollmer P.
Published: April 2008

Summary. We measured the pulmonary clearance of inhaled 99mTc‐DTPA and “Tc‐albumin in rabbits with surfactant dysfunction induced by dioctyl sodium sulphosuccinate and in rabbits with lung injury induced by oleic acid. The animals were tracheotomized and mechanically ventilated. After inhalation of 99mTc‐albumin in ten animals, clearance of the tracer from the lungs was monitored for 90 min. The first 30 min was a control period. Dioctyl sodium sulphosuccinate was then administered in aerosol and after another 30 min oleic acid was injected intravenously. Ten other rabbits were given 99mTc‐DTPA, and clearance was externally recorded for 60 min. Five animals inhaled detergent aerosol and five animals were given oleic acid intravenously after 30 min. Airway pressures, tidal volume, and arterial blood gases were measured before and after each intervention. The half‐life of 99mTc‐albumin in the lung was 442 ± 123 min during the control period, 363 plusmn; 52 min after detergent administration, and 134 plusmn; 18 min after oleic acid administration (P<0.05 compared to control and P<0.01 compared to the period after detergent). The half‐life of 99mTc‐DTPA was 94 plusmn; 16 min before and 10 plusmn; 0.6 min (P<0.01) after detergent administration and 75 plusmn; 12 min before and 18 plusmn; 1.8 min (P<0.01) after oleic acid administration. Gas exchange was not affected by administration of dioctyl sodium sulphosuccinate but markedly impaired after injection of oleic acid. Compliance of the respiratory system remained unaffected by detergent but decreased after injection of oleic acid. The results indicate that the rate limiting factors for the alveolo‐capillary transfer of 99mTc‐albumin and 99mTc‐DTPA are different. Surfactant dysfunction affects the transfer of 99mTc‐DTPA but not 99mTc‐albumin. More extensive injury involving the alveolar epithelium may be required for the clearance of 99mTc‐albumin to increase.
Presyncope caused by central hypovolaemia is not preceded by evoked potential alterations
Authors: Lightfoot J. T. , Thakor N. , Biswijit S. , Hanley D. F.
Published: April 2008

Summary The mechanism(s) responsible for the onset of presyncope during a central hypovolaemic challenge have gone undefined for many years. It has been speculated that a decrease in cerebral blood flow initiates presyncopal responses, which in turn lead to greater decreases in cerebral oxygen delivery and unconsciousness. Somatosensory evoked potentials (SEP) were monitored as a measure of cerebral functioning in ten subjects during presyncopal symptom limiting lower body negative pressure (a central hypovolaemic challenge). SEP latency and amplitudes have been correlated with cerebral oxygen uptake, so SEP activity can serve as an indirect indicator of cerebral homeostasis. SEPs were generated by electrically stimulating the median nerve and recoding the resulting potentials over the contralateral cerebral cortex. While heart rate and mean blood pressure both fell at presyncope, there were no changes noted in either SEP latency or amplitude at any point before (latency = 22.9±9 ms; amplitude = 2.86±0.24 μV), during (22.6±0.9 ms; 2.68 ±0.2 μV), or after (22.7 ±0.9 ms; 2.37 ±0.23 μV) the occurrence of presyncope. We conclude that the onset of presyncope is not associated with a decrease in cerebral function.
Accuracy and repeatability of a pocket turbine spirometer: comparison with a rolling seal flow‐volume spirometer
Authors: Malmberg L. P. , Hedman J. , Sovijärvi A. R. A.
Published: April 2008

Summary. The accuracy and repeatability of a recently introduced pocket spirometer (Micro Spirometer©; Micro Medical Instruments Ltd, Rochester, UK) was evaluated. FEV] and FVC values obtained with this instrument were compared with those measured with a rolling‐seal flow‐volume spirometer (CPI220 with microcomputer) in 31 patients and 11 healthy volunteers. In the whole material, expressed as mean ± SD, the pocket spirometer recorded 0.44 ±0.23 1 (13 ±7%) smaller values for FEV1 (P<0.001) and 0.64 + 0.48 1 (15 ± 11%) smaller values for FVC (P<0.001) than the rolling‐seal spirometer. The short‐term repeatability of the measurements expressed as the coefficient of variation of repeated measurements using the pocket spirometer was 2.2% for FEV1 and 2.3% for FVC in a series of 10 healthy subjects and 10 patients with COPD. It is concluded that the underestimation of FEV1 and FVC of the pocket spirometer was too large and inconsistent for the device to be used interchangeably with conventional spirometers. However, the repeatability of the measurements with the pocket spirometer is close to that reported previously for flow‐volume spirometry. Thus the pocket spirometer may be suitable in assessing acute changes of spirometric indices e.g. during provocation tests or during patient follow‐up in asthma.
Venous plasma noradrenaline increases with age: correlation to total blood volume and long‐term smoking habits
Authors: Jensen E. W. , Eldrup E. , Kelbaek H. , Nielsen S. L. , Christensen N. J.
Published: April 2008

Summary. Venous plasma noradrenaline (NA), cardiac index, total blood volume, and other haemodynamic parameters were measured in 12 young (median age of 29, range 21–37 years) and 10 elderly (median age of 68, range 55–85 years) healthy male subjects in the resting supine and sitting positions. Cardiac index was equal in the two groups and did not correlate to plasma NA. Plasma NA was significantly elevated in the elderly subjects in the sitting position (2.47±0.28 vs. 1.80±0.13 nmol l‐1, P= 0.038). Elevated plasma NA levels were confined to elderly long‐term smokers. Sitting plasma NA was significantly correlated to total blood volume corrected for body weight, r= ‐0.720, P= 0.0002, but with no difference in blood volume between smokers and non‐smokers. It is concluded, that long‐term smoking may result in elevated plasma NA levels seen in elderly subjects. It is suggested, that this is a compensatory mechanism to vascular dilation induced by chronic smoking.
Effects of cold pressor test on circulating atrial natriuretic peptide 99–126 (ANP) in patients with Raynaud's phenomenon and influence of treatment with magnesium sulphate and nifedipine
Authors: Ringqvist I. , Hedner T. , Leppert J. , Niklasson U. , Edvinsson L.
Published: April 2008

Summary. The effect of a standardized cold pressure test (CPT) on the venous concentration of immunoreactive atrial natriuretic peptide (ir ANP) was studied in 12 females with primary Raynaud's phenomenon (PRP) and 12 female age‐matched controls. The test was performed at the end of three stages. During the first stage no medication was given. During the second stage a magnesium infusion was given. After fourteen days of medication with a calcium antagonist (Nifedipine) the third stage of the study was performed.

The venous irANP increased significantly (P < 0.05) 10 min after the start of the CPT both in the PRP group and in the control group (136±39 to 159±54 and 153±45 to 179±40 pg ml‐1, given as mean and SD). Baseline irANP did not change in the PRP group after treatment with magnesium or nifedipine. In the control group nifedipine treatment significantly (P < 0 01) lowered venous irANP compared to the no treatment or magnesium sulphate infusion stages (128±31 vs. 153±45 and 160±41 pg ml‐1). After the CPT in both PRP group and control group the venous irANP did not increase either during magnesium sulphate infusion or nifedipine treatment.

In conclusion the study has demonstrated that a standardized CPT results in a delayed increase in irANP in venous plasma and that magnesium sulphate infusion and nifedipine treatment prevent this increase. Furthermore, our data do not suggest a role for irANP in the symptomatology of primary Raynaud's phenomenon.
Effect of propofol and thiopentone on regional blood flow in brain and peripheral tissues during normoxia and hypoxia in the dog
Authors: Haberer J. P. , Audibert G. , Saunier C. G. , Müller C. , Laxenaire M. C. , Hartemann D.
Published: April 2008

Summary. The effect of propofol and thiopentone on cerebral (CBF), myocardial (MBF), muscular, and arterial hepatic blood flow was assessed with radiolabeled microspheres in 12 chronically instrumented dogs, six given propofol and six thiopentone. Tissue blood flows were measured in the awake animal, after 30 min of normoxic anaesthesia (room air), and after 30 min of hypoxic anaesthesia using a mixture of 10% O2 and 3% CO2 in nitrogen. The decrease in CBF from awake to normoxic anaesthesia was similar with propofol and thiopentone (propofol: 77 ±8 to 38±3 ml min‐1 100 g‐1, P<0.01; thiopentone: 66±3 to 33±2 ml min‐1 100 g‐1, P<0.01). During hypoxia, CBF rose moderately in the two groups (respectively + 19% and +28%, P<0.05). The MBF increased in propofol and thiopentone groups after 30 min of anaesthesia with air (propofol: 97 ±23 to 137 ± 15 ml min‐1 100 g‐1; thiopentone: 82 ±7 to 141 ± 10 ml min‐1 100 g‐1) and increased still more during hypoxia. The increase in MBF was related to an increase in heart rate and blood pressure. The quadriceps blood flow decreased during anaesthesia in normoxia and in hypoxia. The diaphragmatic blood flow increased with thiopentone under hypoxia. The hepatic arterial blood flow was unchanged. It is concluded that the effects of propofol on regional blood flows are very similar to those of thiopentone.
Chloroquine reduces blood pressure and forearm vascular resistance and increases forearm blood flow in healthy young adults
Authors: Anigbogu C. N. , Adigun S. A. , Inyang I. , Adegunloye B. J.
Published: April 2008

Summary. The effects of chloroquine on resting blood pressure, forearm blood flow (FBF), and forearm vascular resistance (FVR) and on the responses to cold stimulation were studied in healthy young adults. Chloroquine sulphate (800 mg) reduced systolic pressure and increased FBF (P<0.05) but had no effect on resting FVR. Cold immersion increased systolic pressure (from 108.8 ±1.7 mmHg to 127.8 ± 6.9 mmHg; P<0.05) diastolic pressure (from 73.4 ±2.7 to 95.2 ±6.2 mmHg; P<0.01) and FVR (from 5.9±0.9 to 13.0±l.9 a.u.; P<0.001) but reduced FBF (from 14.3±1.64 to 101 ± 1.29 ml min‐1; P<0.05). Chloroquine reduced the increase in FVR reduced by cold stimulation (P<0.01), but had little effect on the BF and FBF responses to cold stimulation.

The hypotensive effect of chloroquine could be attributed, at least in part, to the observed fall in vascular resistance.
Age‐related diminution of the cardiovascular autonomic responses: diagnostic problems in the elderly
Authors: Piha S. J.
Published: April 2008

Summary. To study the usefulness of standard cardiovascular autonomic reflex tests in the elderly, 224 healthy controls and 49 aged diabetic patients were examined. Based on the data obtained from healthy controls, age‐related reference values for several autonomic indices were calculated and their usefulness was tested with aged diabetic patients. It was found (1) that in elderly subjects (aged 50 years) the indices based on heart rate differences are more suitable for the assessment the autonomic parasympathetic control than indices based on R/R interval ratios, (2) that the tests (and indices) of choice in the elderly subjects are the Valsalva manoeuvre (Valsalva difference and tachycardia difference) and the active orthostatic test (Max‐Rest difference, immediate and later change in systolic blood pressure), (3) that the usefulness of the deep breathing test is limited in the elderly, (4) that such commonly used indices as the Valsalva ratio and the Max/Min ratio in orthostatic test are not useful in the elderly, and (5) that the isometric handgrip test is of little use in the assessment of the autonomic function in the elderly. In conclusion, standard cardiovascular autonomic reflex tests can be used in the assessment of autonomic function to some extent also in the elderly subjects. However, one must bear in mind the limitations in their applicability in that age group.,
Effect of temperature on finger artery pressure evaluated by volume clamp technique
Authors: Tanaka H. , Thulesius O.
Published: April 2008

Summary. We examined the effect of temperature on digital arterial blood pressure obtained by continuous beat‐to‐beat non‐invasive monitoring with a volume‐clamp technique (Finapres). In 10 normal volunteers and 13 patients with symptoms of vasospasm, digital pressure and brachial artery pressure (cuff method) was simultaneously recorded in control conditions at room temperature, during body cooling, finger heating, and truncal heating. In the control condition digital systolic blood pressure was significantly higher (16.1 14.2 mmHg) than brachial systolic pressure. The augmentation of digital systolic pressure correlated inversely with finger tip temperature. Diastolic and mean arterial pressure did not differ significantly between the two methods. Body cooling augmented the systolic finger‐arm gradient while truncal heating and finger heating had the opposite effect. Finger heating reduced systolic augmentation without changing the mean and diastolic blood pressure. Similar changes were also observed in the patients with vasospasm except in one case with a pronounced Raynaud syndrome where digital blood pressure was lower than brachial artery pressure. We conclude that augmentation of finger systolic pressure seems to be dependent on local vasoconstriction of A/V shunts and that finger heating may be a useful procedure to improve the reliability of Finapres readings.,
Overnight glucose metabolism in obese non‐insulin‐dependent diabetic patients and in healthy lean individuals
Authors: Tappy L. , Acheson K. , Curchod B. , Schneiter Ph. , Normand S. , Pachiaudi C. , Temler E. , Riou J. P. , Jéquier E.
Published: April 2008

Summary. Increased fasting hepatic glucose production is present in NIDDM patients, and has been shown to be due to increased gluconeogenesis. In order to determine the contribution of the cycling between glucose and three‐carbon compounds (Cori and glucose‐alanine cycles) to the increased hepatic glucose production, glucose kinetics measured overnight in seven obese NIDDM patients and six lean healthy subjects with both 6, 6 2H glucose and U‐13C glucose were determined. At 0500 h obese NIDDM subjects showed a 40% increase in glucose appearance calculated from 6, 6 2H glucose, whereas glucose appearance calculated from U‐13C glucose was similar compared to lean subjects, indicating increased glucose cycling. Non‐oxidative glucose disposal was also increased three‐fold in NIDDM patients. Glucose cycling was increased by 111% in NIDDM patients (118 ± 18 μmole min‐1 vs. 56 ± 11 in controls, P<0–05) and was positively correlated with plasma glucose concentration (r= 0–831, P<0–001) and with non‐oxidative glucose disposal (r= 0–714, P<0–01). Four NIDDM patients were studied again after 3 days of insulin therapy. Insulin restored near‐normoglycaemia (7–4 ± 0–8 mmole 1‐1) and normalized rates of glucose appearance and glucose cycling. It is concluded that increased glucose cycling in obese NIDDM patients accounts for a major part of the increased fasting hepatic glucose production and non‐oxidative glucose disposal in obese NIDDM subjects.
Altered autonomic regulation of cardiac function during head‐up tilt after 28‐day head‐down bed‐rest with counter‐measures
Authors: Hughson R. L. , Yamamoto Y. , Maillet A. , Fortrat J. O. , Traon A. Pavy‐Le , Butler G. C. , Giiellr A. , Gharib C.
Published: April 2008

Summary. The effects of 28 days continuous 6° head‐down tilt bed‐rest on heart rate variability and the slope of the spontaneous arterial baroreflex were evaluated during supine rest and the first 10 min of 60° head‐up tilt. Twelve healthy men were assigned to either a no counter‐measure (No‐CM), or a counter‐measure (CM) group so that there was no difference in maximal oxygen uptake. Counter‐measures consisted of short‐term, high resistance exercise for 6 days per week from days 7–28, and lower body negative pressure (‐28 mmHg) for 15 min on days 16, 18, 20 and 22–28. In spite of balanced between‐group fitness, mean RR‐interval was different between the No‐CM and the CM group prior to bed‐rest, but neither this nor any other variables showed significant counter‐measure by bed‐rest interaction effects. Therefore, all data presented are from the main effects of bed‐rest or tilt from the analysis of variance. RR‐interval was reduced significantly by bed‐rest and by tilt (P<0–0001). Indicators from spectral analysis of heart‐rate variability suggested reduced parasympathetic nervous system activity with bed‐rest (P<0–01) and head‐up tilt (P<0–05), and increased sympathetic nervous system activity after bed‐rest (P<0–01). An indicator of complexity of cardiovascular control mechanisms, taken from the slope (β) of log spectral power vs. log frequency relationship, suggested reduced complexity with bed‐rest (P<0–05) and head‐up tilt (P<0–01). The spontaneous baroreflex slope was reduced significantly by bed‐rest (P<0–03) and by head‐up tilt (P<0–04). Taken together, these data support the concept of altered autonomic nervous system function in the aetiology of cardiovascular deconditioning with bed‐rest or space travel; and it would appear that no benefit is derived from these specific counter‐measures.
Positron emission tomography in oncology
Authors: Leskinen‐Kallio S.
Published: April 2008

Summary. The particular advantages of positron emission tomography (PET) technique are that it has higher sensitivity, higher resolution, and a higher quality of image than that found in conventional nuclear medicine. The possibility of quantification and the wide range of useful tracers have raised expectations of this new method. To date, most of the human PET cancer studies have been performed with [18F]fluorodeoxyglucose (FDG) or [11CJmethionine. These are good imaging agents for tumours. However, more specific radiopharmaceuticals are required if other features of tumour metabolism are to be observed, f11Thymidine may prove to be a good tracer for quantitative measurements of tumour proliferation and [18F]misonidazole has been suggested for imaging of hypoxia.
Biphasic response of plasma endothelin‐1 concentration to exhausting submaximal exercise in man
Authors: Richter E. A. , Emmeluth C. , Bie P. , Helge J. , Kiens B.
Published: April 2008

Summary. The concentration of endothelin‐1 in forearm venous plasma was measured in 10 healthy men at rest and during ergometer bicycling at 65% of maximal aerobic capacity until exhaustion (96± 10 min, mean ± SE). A control group of 10 comparable subjects rested for 2 h. Mean plasma endothelin‐1 concentration at rest was 2–0 ± 0–2 pg ml‐1, n= 20. The concentration decreased significantly by 21% during the first 30 min of exercise, whereupon it increased so that the concentration after 60 min of exercise was no different from resting values. The change in endothelin concentration could not be explained by changes in plasma volume. Unspecific effects of catheterization or time could also not explain the change in endothelin‐1, since in the 10 control subjects who did not exercise, plasma endothelin‐1 did not change significantly over 120 min. It is concluded that the concentration of endothelin‐1 in forearm venous plasma changes in a biphasic manner during prolonged exhaustive bicycle exercise in man. An initial decrease in concentration is followed by an increase restoring the concentration to resting values after 60 min exercise.
Transcutaneous oxygen pressure measurements in patients with intermittent claudication
Authors: Rosfors S. , Celsing F. , Eriksson M.
Published: April 2008

Summary. Transcutaneous oxygen pressure (TcPO2) measurements were performed on 10 male patients with moderate‐to‐severe intermittent claudication. The TcPO2 electrode was attached to the dorsum of the foot. TcPO2 response to a standardized treadmill exercise test was evaluated, as was the reproducibility of TcPO2 measurements at rest and during exercise. Reproducibility was assessed using a similar exercise test within 2–5 days. Treadmill exercise induced a marked decrease in TcPO2 in all patients, from 9–3 ± 0–9 to 2–8 ± 2–0 kPa. Maximal walking distance was 280 ± 127 m at the first treadmill test and 272 ± 113 m at the second. Blood lactate and heart rates at rest and at end of exercise were also unchanged. TcPO2 at rest was highly reproducible, but considerable variation was found for measurements during and after exercise. This variation was most obvious for measurements during exercise and no direct or reproducible relation was found between ischaemic calf pain and TcPO2 values. Post‐exercise measurements were slightly more reproducible and somewhat easier to assess. In contrast to standard TcPO2 measurements, total exercise‐induced ischaemia expressed as area under the post‐exercise TcPO2 curve was highly reproducible. In summary, our results with TcPO2 measurements in patients with intermittent claudication showed a marked exercise‐induced decrease in all patients. However, the variation in TcPO2 values when the test was repeated after 2–5 days under stable clinical and circulatory conditions limits its application as a quantitative measure of lower‐limb ischaemia. Thus, measurements of area under the TcPO2 curve might be preferred for this purpose.
Effect of acute dose of caffeine on cardiovascular autonomic responses in healthy subjects
Authors: Piha S. J.
Published: April 2008

Summary. The effect of acute dose of caffeine (4 mg kg‐1) on cardiovascular autonomic responses were studied in 10 healthy subjects. Standard cardiovascular reflex tests were used during which heart rate and blood pressure were continuously measured. Each subject was tested twice in a random order, with and without prior use of caffeine. It was found that immediate heart rate responses following standing up were lower under influence of caffeine. Blood pressures were systematically, although non‐significantly, higher and blood pressure responses in isometric handgrip test stronger when caffeine was used before testing. It is suggested that caffeine should not be used before autonomic testing. This is especially important when the test(s) are performed for research purposes or in order to study the blood pressure responses. If the tests are made for diagnostic purposes the following rules should be adopted: (1) if the subject has used caffeine before testing but all heart rate responses are within normal ranges, it can be assumed that the subject does not have cardiac parasympathetic neuropathy and retesting is not necessary; (2) if the patient has used caffeine before testing and the results suggest presence of autonomic neuropathy, the patient must be retested without the prior use of caffeine.
Growth hormone (GH) treatment in GH‐deficient adults: effects on muscle size, strength and neural activation
Authors: Sartorio A. , Narici M. V.
Published: April 2008

Summary. The effects of 6 months of recombinant growth hormone (GH) treatment (0–5 IU kg‐1 per week) on muscle size, strength and neural activation (EMG) was studied in eight adults with childhood onset GH deficiency (GHD). Before treatment, height, body mass (BM) and lean body mass (LBM) 6f the GHD subjects were significantly lower (P<0–01) from those recorded in eight healthy controls, while no significant differences were found between the body mass index (BMI) of the two populations. Thigh muscle + bone cross‐sectional area (CSAM+B) and lower limb muscle plus bone volume (LLVM+B) of the GHD patients were 66–1 ± 13–7% and 47–6 ± 6–8% of those recorded in the controls (P<0–01), whereas no difference in CSA/height2 was found between the two groups. By contrast, LLVM+B/height3 was 82–0 ± 19–0% that of the controls (P<0–05). Similarly, quadriceps muscle strength (MVC) of the GHD patients was 63–2 ± 12–4% that of controls (P<0–01), while no significant differences in the force per unit area (F/CSA) and per body mass (F/BM) were found. After 6 months of GH treatment LBM increased by 6–0 ± 4–2% (P<0.02), CSAM+B by 14–5 ± 12–7% (P<0.01) and LLVM+B by 10‐l ± 7–3% (P<0.01), absolute differences from the normals still persisting. However, the LLVM+B/height3 of the GHD patients after treatment was no longer significantly different from that of the controls. Quadriceps MVC increased by 9–8 ± 12–0% (P<0–02), differences from the controls being still significant, whereas the F/CSA and F/BM did not change. A right shift of the integrated EMG/Force relation, with no change in the maximal integrated EMG (iEMG) activity, was observed in the patients after treatment. In conclusion, the current study shows that adults with childhood onset GHD have a reduced skeletal muscle mass and strength which seem to be positively influenced by 6 months of GH treatment.
Weight carrying effects on treadmill exercise response in persons without heart disease
Authors: Takehana K. , Sugiura T. , Nagahama Y. , Hasegawa T. , Iwasaka T. , Inada M.
Published: April 2008

Summary. To evaluate the effect of weight carrying on dynamic exercise response, 12 normal subjects were studied during treadmill exercise using ear densitography in two ways: (1) no weight, (2) 10 kg weight in one hand. Although there were no significant differences in diastolic time (DT), tension‐time index [TTI: systolic blood pressure X heart rate (HR)xleft ventricular ejection time (LVET)] was significantly higher throughout the weight carrying exercise compared to dynamic exercise. The amount of change (A) in TTI was significantly larger in the initial stage (control to 1 min) of weight carrying exercise compared to dynamic exercise, but there were no significant differences in the later stages (1–3 min and 3–6 min). A prolongation in LVET was observed despite increasing HR during the first minute of exercise in both type of exercise, but LVET was longer at any given HR in weight carrying compared to dynamic exercise. Thus, despite higher TTI throughout the weight carrying exercise, Δ TTI was larger only in the initial stage which was caused by prolongation of LVET resulting from disproportionate increase in venous return of early exercise.