bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation between computer‐assisted femoral arteriography and physiological tests in hypercholesterolaemic patients: a methodological study with special reference to clinical trials
Authors: Nilsson S. , Kaijser L. , Erikson U. , Johansson J. , Walldius G. 
Published: April 2008

Summary. The validity of computer‐assisted femoral arteriography, for the study of regression/progression of atherosclerosis in follow‐up clinical trials, was investigated by comparison with routine physiological estimates of peripheral circulatory function. Thus, in 114 hypercholesterolaemic patients, the results of aorto‐femoral arteriography were compared with those of leg segmental blood pressure measurement, oscillometry, digital pulse plethysmography, and bicycle and treadmill exercise tests. In 107 patients, 18 with symptoms of peripheral vascular disease (PVD) and 89 asymptomatic, magnification arteriograms of a 20 cm segment of the right or left superficial femoral artery were obtained. These arteriograms were digitized and the following variables were calculated: arterial lumen volume (corrected for body size), per cent stenosis, and edge roughness. The correlation between arteriographic and physiological variables was investigated with a linear regression model, taking into account the possible interaction with sex, and presence or absence of symptoms of PVD. Lumen volume correlated significantly with all five physiological variables, and per cent stenosis correlated significantly with four of the physiological variables. For the roughness measure, however a significant correlation was found only with plethysmography.By using logistic multiple regression analysis linear functions of physiological variables were constructed to detect ilio‐femoral arterial occlusion. The sensitivity specificity for detection of right‐sided, left‐sided, and bilateral occlusion was 0.83/0.98, 0.78/0.98, and 0.60/1.00 respectively (N = 108–111). Systolic blood pressure (ankle‐arm ratio) was the single variable most closely correlated to the likelihood of arterial occlusions.It is concluded that arterial lumen volume and per cent stenosis, measured for the digitized femoral arteriogram, correlate well with physiological variables, which
Exercise echocardiography: a methodological study comparing peak‐exercise and post‐exercise image information
Authors: Blomstrand P. , Engvall J. , Karlsson J. E. , Björkholm A. , Wallentin L. , Wranne B. 
Published: April 2008

Summary. It is unclear whether echocardiography at peak bicycle exercise adds information to registrations obtained recumbent immediately after the test and what factors influence image quality. Therefore, exercise echocardiography was performed consecutively and prospectively in 66 men, unselected with regard to echocardiography, one month after an episode of unstable coronary artery disease.Of 594 segments (9 × 66), 569 (96%) were adequately visualized recumbent at rest. The corresponding figures recumbent directly after exercise, seated before exercise, and seated at peak exercise were 544 (92%), 474 (80%), and 428 (72%), respectively. In the majority of our patients, acceptable images at peak exercise were obtained for the septal region, while for the anterior, lateral, and inferior segments the success rate varied from 50 to 70%. Recumbent after exercise, the success rate was acceptable for most segments, possibly with the exception of the apical and lateral segments.Fifty‐five patients developed new wall motion abnormalities or worsening of wall motion in connection with exercise. Echocardiography at peak exercise provided more information than afterwards in patients with images of good quality. However, in patients with inferior image quality, the registrations obtained recumbent after the test revealed wall motion abnormalities which were not obtained seated at peak exercise. Patients with worse image quality had significantly higher respiratory rate and weight, and rated a higher degree of dyspnoea at peak exercise than those with good quality.We conclude that in middle aged men with coronary artery disease, image acquisition at peak bicycle exercise and immediately after exercise are of complementary value.
Ambulatory strain‐gauge plethysmography and blood volume scintimetry for quantitative assessment of venous insufficiency
Authors: Struckmann J. R. , Vissing S. Fløistrup , Hjortsø E. 
Published: April 2008

Summary In the present study, a strain‐gauge plethysmographic method (ASGP) is compared to an isotope plethysmographic method (ABVS), in order to evaluate how an externally recorded volume change corresponds to blood displacement within the leg during exercise. The coefficient of correlation for RT (venous return time) was 0.67 (P<0.001) and for EV (expelled volume) it was 0.61 (P<0.001).The RT values were similar by the two methods both in healthy controls and in patients with Chronic Venous Insufficiency (CVI). The corresponding EV values showed the same pattern in controls and patients but the values differed substantially. By ASGP the value was approximately 2 ml per 100 ml tissue compared to 33 ml per 100 ml blood by the ABVS method.Both methods could clearly distinguish normal controls from patients with chronic deep venous insufficiency, but ABVS could only make this distinction when the ankle area of measurement was applied.
Scintigraphic detection of gastro‐pulmonary aspiration in patients with respiratory disorders
Authors: Ruth M. , Carlsson S. , Månsson I. , Bengtsson U. , Sandberg N. 
Published: April 2008

Summary. The scintigraphic detection of small nocturnal aspirations of radio‐labelled gastric contents is difficult in the presence of high remaining activity in the abdomen, causing a non‐uniform background activity. This problem was examined in phantom experiments and a technique for interpolative background correction was further developed. The accuracy of this technique was found to be influenced by the distance between the lung and the abdominal source of activity, and the minimum detectable ‘aspirated’ activity was determined as 0.1 MBq at a distance of 15 cm and 1 MBq at 5 cm.The interpolative technique for background correction was evaluated on healthy volunteers and laryngectomized patients, examined 10 h after intragastric instillation of 200 MBq of 99Tcm‐pertechnetate. After background subtraction, their calculated pulmonary mean net count value was comparable to that registered before the radioactive tracer was administered. No localized accumulation of activity was found in any of these controls.The technique was then applied clinically to 55 patients with chronic respiratory disorders and symptoms of gastroesophageal reflux. Aspiration was detected in 11 patients (20%). Five aspirators had asthma, two a chronic cough of unknown origin, two recurrent pulmonary infections, and one chronic bronchitis and chronic laryngitis respectively. Aspiration was detected among patients with and without demonstrated pathological gastroesophageal reflux.
Non‐invasive estimates of aortic root pressures: external subclavian arterial pulse tracing calibrated by oscillometrically determined brachial arterial pressures,
Authors: Aakhus S. , Torp H. , Haugland T. , Hatle L. 
Published: April 2008

Summary. This investigation assessed the ability of a non‐invasive method to reproduce aortic root pressure waveform and pressures. An external pulse tracing of the subclavian artery was obtained simultaneously with direct aortic root pressures during routine left heart catheterization in 26 patients (aged 39–74 years) with various cardiovascular disorders. Indirect brachial arterial peak‐systolic and nadir‐diastolic pressures were obtained with oscillometry. The direct and indirect peak‐systolic and nadir‐diastolic pressures, were separately used to calibrate the pulse tracing.Adequate pulse tracing was obtained in 19 patients (73%). The waveforms agreed well with cross‐correlation coefficients for systole and diastole of 0.98. The difference between the pulse trace and the direct pressure curve, when the first was calibrated with the peak‐systolic and nadir‐diastolic pressures of the latter on average was less than 1 mmHg for systole and diastole. At end‐systole the mean difference was 5 mmHg.Oscillometric brachial arterial peak‐systolic pressures were (meanSD) 37 mmHg below the corresponding direct measurements, while diastolic pressures were 84 mmHg above. The difference between the pulse trace and the direct pressure curve, when the pulse trace was calibrated with oscillometric pressures, was at end‐systole 66 mmHg and for mean arterial pressures 54 mmHg.Thus, the external subclavian arterial pulse tracing provides a non‐invasive, clinically feasible access to the aortic root pressure waveform. With optimal calibration, good estimates of aortic root pressures throughout systole and diastole can be obtained, while end‐systolic pressure tends to be slightly overestimated.
Cutaneous and subcutaneous blood flow rates in paraplegic humans investigated by 133Xenon wash‐out. Methodological considerations
Authors: Sørensen J. L. , Hauge E. N. , Wroblewski H. , Biering‐Sørensen F. 
Published: April 2008

Summary. In a methodological study including 14 paraplegics and seven normal controls cutaneous and subcutaneous blood flow rates were investigated by 133Xenon wash‐out after atraumatic labelling. In paraplegics, areas suffering pressure sores were included. The method was found applicable for the authors' purposes. In seven paraplegics median (95% confidence limits) cutaneous blood flow was 5–2 (2–4–8–5) ml (100 g min)“1 and subcutaneous 4–3 (2–0–13–2) ml (100 g min)‐1. This did not differ from normal controls. In seven paraplegics with ischial pressure sores a trend for increased cutaneous blood‐flow rates from areas adjacent to sores was obvious (P= 0–06).During 704 head‐up tilt, elimination‐rate constants were reduced by a factor of 0–54 (0–50–0–70). A proximal blockade or infiltration of the 133Xenon depots with lidocaine did not inhibit employment of the method. The proximal block did not alter the local blood flow rate, but infiltration increased it in both paraplegics and normal individuals. Intra‐ and interdepot coefficients of variation were about 11% and 40% respectively. Interindividual coefficients of variation varied between 25% and 46%.
Skin microcirculatory and thermal changes in elderly subjects with early stage of pressure sores
Authors: Schubert V. , Perbeck L. , Schubert P.‐Å. 
Published: April 2008

Summary. Elderly subjects are prone to develop pressure sores over the sacrum area mainly due to external pressure and shear effects which negatively affect the skin microcirculation. The aim of the study described here was to measure skin microcirculatory and thermal changes in twelve elderly patients with an early stage of pressure sore and in ten elderly subjects without pressure sore. The total skin microcirculation at a damaged risk area, the sacrum, and a reference area of undamaged skin over the gluteal region, was evaluated using the laser Doppler fluxmetry. The nutritive transport of small solutes, characterized by the transcapillary exchange of sodium fluorescein, was evaluated using the fluorescein flowmetry technique. The skin temperature was measured with a thermoelement.The skin microcirculation at the area with an early stage of pressure sore was significantly higher than at undamaged skin as measured by both techniques. The total microcirculatory blood flow increased > 16 times (P < 0–001) and the nutritive transport 5 times (P < 0–01) compared to the reference value, and the calculated blood flow of subpapillary tissue layers increased 17–19 times (P < 0–001). However, the skin temperatures in damaged and undamaged skin did not differ significantly.These results show an increased skin microcirculation in the early stage of pressure sores but no increase in skin temperature. The more strongly increased skin blood flow in subpapillary tissue layers effectively conducts away the heat caused by the damage and the increased metabolic activity.
Assessment of coronary artery stenosis pressure gradient by quantitative coronary arteriography in patients with coronary artery disease
Authors: Atar D. , Ramanujam P. S. , Saunamaki K. , Haunsø S. 
Published: April 2008

Summary. The aim of the study described here was to correlate coronary artery (CA) stenosis pressure gradients calculated by quantitative coronary arteriography (QCA) to invasively measured transstenotic pressure drops in patients with anginal symptoms and with known or suspected coronary artery disease. Furthermore, the known mathematical models are improved by introducing (1) pressure catheter‐corrected minimal stenosis area, (2) modification of flow assumptions, and (3) stenosis exit angle.Included in the study were 45 patients with 61 stenoses. The visually estimated CA lesion severity in these non‐complex stenoses was in the equivocal range of 40–70%. All measurements were performed after intracoronary administration of nifedipine and nitroglycerine. Stenosis dimensions were assessed from magnified cinefilms, using handheld calipers.Highly significant overall correlation was found between measured and calculated pressure gradients with correction for the impact of the intracoronary catheter (P < 0–00001, r= 0–84). In particular, a substantial number of stenoses with haemody‐namically‐insignificant pressure gradients were identified by hydrodynamic calculations. In conclusion, the great majority of the coronary artery stenoses could be classified reliably by QCA as being haemodynamically insignificant or significant, respectively.,
Local cooling prolongs oesophageal transit in humans
Authors: Jørgensen F. , Hesse B. 
Published: April 2008

Summary. The influence of local cooling on oesophageal transit was studied in eight healthy volunteers by oesophageal radionuclide transit. Compared with lukewarm (18C) water a significantly prolonged mean transit time (MTT) was found after ingestion of cold liquid (4C) and a slightly shorter MTT with 50C. The effect was of short duration lasting less than 2 min.The effect of atropine, morphine and naloxone, on the influence of local cooling was evaluated. Morphine (7‐5 mg i.v.) abolished the effect of cooling on MTT. Naloxone (1–6 mg i.v.) reduced the effect of cooling, but the difference between 4C and 19C was significant still. Atropine (1 mg i.v.) had no effect on the increase in MTT at 4C.It is concluded that in humans local cooling increases oesophageal MTT. Local warming shortened MTT slightly. The abolishment of the influence of cooling by morphine suggests that opioids may be involved.,
Increased transcapillary escape rate of albumin in elderly subjects due to long‐term smoking habits
Authors: Jensen E. W. , Espersen K. , Knudsen J. H. , Nielsen S. L. 
Published: April 2008

Summary. Transcapillary escape rate of albumin (TER) expressed as percentage decrease in specific activity of plasma albumin per hour was measured in 44 healthy male subjects, 10 young non‐smokers (median age 24.0 years, range 21–33), 10 young smokers (30.5 years, range 27–36), 10 elderly non‐smokers (64.0 years, range 51–75) and 14 elderly smokers (61.5 years, range 54–69). In addition urinary albumin excretion rates were measured in 15 of the elderly subjects. The subjects were investigated after overnight fasting and abstention from tobacco. Median TER was 7.33% (interquartile range 5.82–9.90) in the elderly smoking subjects. This value was significantly elevated as compared to elderly non‐smokers, 4.47% (2.93–5.83), young non‐smokers, 3.70% (2.24–6.30) and young smokers, 4.25% (2.80–4.44). A statistically non‐significant (P=0.064) tendency of a higher urinary albumin excretion rate was observed in elderly smokers. This agrees with other investigations showing slightly increased albuminuria in smokers compared with non‐smokers. The differences were not related to differences in blood pressure, plasma cholesterol, weight, or abuse of alcohol in the elderly subjects. Diabetic subjects with an increased TER to levels comparable with levels in long‐term smokers have increased urinary albumin excretion rates, which seems to be greater than in long‐term smoking subjects.It is suggested that increased TER in long‐term smokers may indicate a vascular dysfunction affecting either capillary permeability or endothelial surface area.
Pilocarpine iontophoresis test: an index of physiological sweat secretion?
Authors: Hjortskov N. , Jepsen L. T. , Nielsen B. , Juul A. , Skakkebæk N. E. 
Published: April 2008

Pilocarpine iontophoresis test: an index of physiological sweat secretion?Summary. The pilocarpine iontophoresis test (P‐test) is used as a predictor of the capacity to produce sweat. Therefore, we studied the reproducibility of this test in 12 normal subjects on 10 consecutive days. Furthermore, we determined whether the P‐test reflects whole‐body and regional sweat secretion during exercise in the heat. Finally, we determined whether the P‐test stimulates the eccrine sweat glands to maximal sweat secretion. Six growth hormone‐deficient (GHD) patients who are known to have decreased sweating, and 11 healthy control subjects were studied. To induce maximal sweat secretion, the patients exercised on a bicycle ergometer at a workload corresponding to 40% of their maximal aerobic power (VO2max). The 11 healthy subjects exercised at a workload of 150 W. All subjects exercised for 60 min in ambient air at 35°C, with 50% relative humidity. The P‐test showed a mean day‐to‐day variation of 20‐8% between individual subjects. There was a significant positive correlation between the P‐test and regional sweat secretion (r2=0.74). The correlation coefficient (r2) was 0.50 for the correlation between the P‐test and whole‐body sweat secretion, and 0.52 for the correlation between regional sweat secretion and whole‐body sweat secretion. We conclude that the pilocarpine iontophoresis test reflects heat‐ and exercise‐induced sweating capacity. However, this test does not induce maximal sweating, and it cannot be used as a single reliable predictor of whole‐body sweating, due to considerable day‐to‐day variation.
Exercise capacity in heart failure patients: relative importance of heart and skeletal muscle
Authors: Magnusson G. , Kaijser L. , Rong H. , Isberg B. , Sylvén C. , Saltin B. 
Published: April 2008

Summary. The knee extensor and the whole‐body exercise capacities were measured in 11 chronic heart failure (CHF) patients and 11 healthy age‐ and sex‐matched controls, and were related to ejection fraction and to biochemical and histochemical markers of the musculature.The CHF patients had a 39% lower maximal oxygen uptake measured on an ergometer cycle than the healthy controls (1.54±0.57 vs. 2.51±0.70 1 min‐1, P < 0.001). The low exercise capacity was markedly related to the ejection fraction (r =0.77, P < 0.001)TThe maximal strength of m. quadriceps femoris was 15% lower in the CHF patients than in the controls (P < 0.05). The cross‐sectional area (CSA) of m. quadriceps femoris explained 55% (r =0.74, P < 0.001) of the difference in strength between both groups. The endurance capacity of m. quadriceps femoris was 30% lower in CHF patients than in controls, partly as a result of the 25% lower capillary density (P < 0.05) and the 27% lower aerobic enzyme capacity (P < 0.05), as estimated by the citrate synthase activity, in the CHF patients. The citrate synthase activity correlated with the maximal oxygen uptake (r =0.61, P < 0.05). Moreover, the ejection fraction, together with the CSA of m. quadriceps femoris, explained 75% (r =0.86, P < 0.01) of the difference in maximal oxygen uptake between CHF patients and controls.These results demonstrate that CHF patients have both a lower local and a lower whole‐body work capacity than healthy controls. This is a function of a smaller leg muscle mass and a lower capillary density and mitochondrial enzyme capacity in the CHF patients; however, a lowered pump capacity of the heart is the factor which limits the exercise capacity the most.
Ex Ante Impact Assessment under Imperfect Information: Biotechnology in New Member States of the EU
Authors: Demont Matty , Cerovska Marie , Daems Wim , Dillen Koen , Fogarasi József , Mathijs Erik , Muška František , Soukup Josef , Tollens Eric 
Published: April 2008

AbstractSome argue that the lack of modern agricultural development in the former socialist countries of Central and Eastern Europe has made cutting‐edge biotechnology attractive. However, enthusiasm for planting genetically modified (GM) crops varies greatly in the enlarged European Union (EU) and especially among the New Member States (NMS); the Czech GM maize area is progressively growing whereas Hungary imposed a de facto ban on GM crops. Remarkably, the Hungarian ban was not supported by any cost–benefit assessment. In the literature, ex ante impact assessments of monopolistically priced technologies are often based on cross‐sectional comparisons of average cropping budgets. Such assessments ignore heterogeneity of farmers and underestimate the true impact of these technologies because of homogeneity bias. Therefore, we propose an improved method by explicitly modelling farmer heterogeneity under imperfect information, and assess the potential value and benefit sharing of GM crops in the two NMS using a stochastic partial equilibrium model. The total potential value of GM crops is estimated at €82 million for both countries, of which €60 million (73%) accrues to farmers and €22 million (27%) to the gene developers and the seed industry. This is in line with the literature on global benefit sharing of first‐generation GM technologies.
Time to Symptomatic Vascular Stenosis at Different Locations in Patients with Arteriovenous Grafts
Authors: Bozof Ryan , Kats Mark , Barker Jill , Allon Michael 
Published: April 2008

AbstractMost arteriovenous grafts fail due to irreversible thrombosis, superimposed on hemodynamically significant vascular stenosis. Previous studies observed the highest frequency of stenosis at the venous anastomosis, without addressing the timing of stenosis. The present study quantified time to symptomatic stenosis at different vascular locations, and related it to permanent graft failure. A prospective computerized vascular access database was queried retrospectively to identify 309 hemodialysis patients receiving new upper extremity grafts during a 4‐year period at a large dialysis center. For each vascular site we calculated the time to symptomatic stenosis using survival techniques. The cumulative likelihood of symptomatic stenosis at 2 years was 67% for venous anastomotic stenosis, 19% for intra‐graft stenosis, 16% for venous outlet stenosis, 13% for central vein stenosis, and 5% for arterial anastomotic stenosis. The cumulative risk of graft failure at 2 years was 40%. Stenosis at the venous anastomosis was twice as likely as cumulative graft failure (hazard ratio [HR] 1.95; 95% confidence interval [CI], 1.65–2.52, p < 0.001). In contrast, intra‐graft stenosis was half as likely as cumulative graft failure (HR 0.45; 95% CI, 0.36–0.61, p < 0.001). Central vein stenosis was more likely in patients with a previous ipsilateral catheter compared with those without one (HR 2.40; 95% CI, 1.39–5.58, p = 0.004). Symptomatic stenosis occurs much earlier at the venous anastomosis compared with other vascular sites. Moreover, preexisting ipsilateral internal jugular dialysis catheters more than double the risk of central vein stenosis.