bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of glucose and fructose ingestion on the capacity for long‐term exercise in well‐trained men
Authors: Bjorkman Ola , Sahlin Kent , Hagenfeldt Lars , Wahren John 
Published: April 2008

Summary. The aim of the present study was to examine the influence of glucose and fructose ingestion on the capacity to perform prolonged heavy exercise. Eight well‐trained healthy volunteers exercised on a bicycle ergometer at 68±3% of their VO2 max until exhaustion, on three occasions, with 8‐day intervals. During the exercise they ingested either glucose (250 ml, 7%), fructose (250 ml, 7%) or water (250 ml) every 20 min in a double‐blind randomized study design. Arterial blood samples were collected at rest and during exercise for the determination of substrates and hormones. Muscle glycogen content (m. quadriceps femoris) was measured before and after exercise. The duration of exercise lengthened with repeated exercise (3rd test: 136±13 min v. 1st test: 110±12 min, P<0·01). Corrected for the sequence effect, total work time until exhaustion was significantly longer with glucose (137±13 min) than with either fructose (114±12 min) or water (116±13 min) (both P<0·01). When glucose or fructose was ingested, the arterial plasma glucose concentration was maintained at the normoglycaemic level; with water ingestion, plasma glucose values fell during exercise in seven subjects and remained at the resting level in the eighth subject. The muscle glycogen concentration was 467±29 mmol kg d.w.‐1 at rest and fell to approximately half the initial value at exhaustion. In the subgroup of seven subjects in whom glucose values decreased with water intake, the mean rate of glycogen degradation was significantly lower (P<0·05) with the ingestion of glucose (1·3±0·4 mmol kg d.w.‐1 min‐1) as compared to fructose (2·1±0·5 mmol kg d.w.‐1 min‐1) or water (2·3±0·5 mmol kg d.w.‐1 min‐1).Intermittent glucose ingestion (3×17·5 g h‐1) during prolonged, heavy bicycle exercise postpones exhaustion and exerts a glycogen‐conserving effect in the working muscles. In contrast, fructose ingestion during exercise maintains the glucose concentration at the basal level but fails to influence either muscle glycogen degradation or endurance performance.
Reference values for exercise tests with continuous increase in load
Authors: Nordenfelt I. , Adolfsson L. , Nilsson J. E. , Olsson S. 
Published: April 2008

Summary. Reference values for exercise tests with continuous increase in load are presented. The exercise tests were performed on an electrically braked bicycle ergometer by 188 randomly selected Swedes of both sexes who were between 20 and 79 years of age.The reference values are related to sex, age (in decades) and weight and classified in decreasing levels of exercise capacity.Reference values for systolic blood pressure at different work loads are also given.
REGIONAL LUNG FUNCTION: PHYSIOLOGY AND CLINICAL APPLICATIONS
Authors: Hughes J. M. B. 
Published: April 2008

SUMMARYThe current status of tests of regional lung function has been reviewed from the physiological and clinical standpoint. Recent technical innovations include the use of single photon and positron emission computerized tomography (SPECT and PET). For PET work, neon‐19 (t1/7 17 sec) has been introduced as a ventilation tracer, and fluorine‐18 deoxyglu‐cose as a marker of glucose metabolism. Indium‐111 labelled neutrophils have been studied. Physiological measurements of the distribution of blood flow and ventilation are concentrating on non‐gravitational influences such as the pattern of force generation by the respiratory muscles and vasomotor tone. Ventilation and perfusion imaging of the lung with the gamma camera has established itself as an essential screening test for the diagnosis of pulmonary embolic disease. Inhalation of a radio‐labelled aerosol of small particle size (1 μm) may be an acceptable substitute for a radioactive gas ventilation scan. Mucociliary clearance has been investigated with radionuclide techniques. Measurements of regional lung water have been replaced by tracers sensitive to alterations of epithelial (inhaled 99TCI‐DTPA) or endothelial (i.v. 113inm‐transferrin) permeability. New techniques using positron emission tomography, such as measurements of extravascular lung density, regional ventilation (19Ne) and regional glucose metabolism (18F‐deoxy‐glucose) have been discussed briefly.
EXERCISE CAPACITY IN SUBJECTS WITH HIGH OXYGEN AFFINITY
Authors: Länsimies Esko , Hyödynmaa Simo , Lahtinen Reino , Mahlamäki Eija , Palomäki Pertti , Rautiainen Matti 
Published: April 2008

SUMMARYExercise capacity and hemodynamic parameters were measured in ten patients with a previously unpublished variant of hemoglobin (Hb‐Linkbping) and in ten age‐ and sex‐matched controls. Bicycle ergometer test was almost maximal and the indices of working capacity and cardiac tolerance were similar in patients and controls. The hemoglobin dissociation curve was shifted to the left at rest and after exercise the shift to right was half of the corresponding shift in controls.Lactate accumulation during exercise was similar in patients and controls, also the elimination rate seems identical, but requires further studies.Hydrogen ion production in the patients during exercise was more marked than in the controls. If this is a sign of altered energy metabolism remains to be ascertained in future studies. In acute short‐term exercise the patients with abnormally high hemoglobin oxygen affinity seem to have similar tolerance and cardiovascular load. Aberrant metabolism and adaptation to relative hypoxia in spite of erythrocytosis may have long‐term effects that require long‐term follow‐up of these patients.
GAS EXCHANGE DURING MECHANICAL VENTILATION
Authors: Carlsson Christer , Jorfeldt Lennart , Carlsson Lena , Hesselvik Fredrik 
Published: April 2008

SUMMARYIn an experimental model using a Servo‐ventilator (Siemens‐Elema, Sweden) oxygen consumption (V'O2) and carbon dioxide production (V'CO2) were measured at varying FIO2‐ Gas exchange was simulated by adding N2 or CO2 to the inspiratory line of the ventilator. Inspiratory and expiratory gases were collected in Douglas bags for analyses by a mass spectrometer. The residual standard deviation for the regression of measured V'O2 on predicted V'O2 was 14 ml/min and did not significantly differ from the line of identity. For V'CO2 the corresponding residual standard deviation was 3 ml/min. This regression line deviated by ‐3% from the line of identity.
WHAT CAUSES THE LOWERED FRC DURING ANAESTHESIA?
Authors: Hedenstierna Goran , Strandberg Åke , Brismar Bo , Lundquist Hans , Tokics Leif 
Published: April 2008

SUMMARYFunctional residual capacity (FRC) by means of body plethysmography chest‐abdomen dimensions by whole body computerized tomography, central blood volume (CBV) by double‐indicator dilution technique and extremity (peripheral) blood volume (PBV) by segmental thigh and upper arm plethysmography, were assessed in lung‐healthy patients who were to undergo general anaesthesia and elective surgery. Anaesthesia was induced by thiopentone and was maintained either by a continuous drip of thiopentone or by inhalation of halothane. Muscle relaxation was obtained by pancuronium bromide. Anaesthesia caused a reduction of the total thoracic volume by an average of 0.75 1. This followed from a cranial shift of the diaphragm and to less extent by a reduced transversal chest area. FRC was concomitantly reduced by an average of 0.5 1 and the CBV, mainly thoracic blood, was reduced by 0.25 ‐ 0.3 1. PBV was slightly reduced by 0.1 1, and it is concluded that these fractions of CBV and TBV must have been pooled in the abdomen. This pooling resulted in more or less maintained transversal abdomen area despite the cranial shift of the diaphragm.
Association between low habitual physical activity and impaired glucose tolerance
Authors: Annuzzi G. , Vaccaro O. , Caprio S. , Bonito P. Di , Caso P. , Riccardi G. , Rivellese A. 
Published: April 2008

Summary. . The aim of this study was to evaluate whether a relationship exists between impaired glucose tolerance and both habitual physical activity and physical working capacity.Sixty‐five apparently healthy subjects with impaired glucose tolerance (according to criteria of the European Association for the Study of Diabetes), age range 40–59 years, and 125 subjects with normal tolerance, sex, age and body mass index matched, were selected among the participants in a health examination survey.They filled in a questionnaire on daily physical activity during work and leisure time and performed an exercise test on a cyclergometer.No difference in physical activity at work was recorded between the groups, but the proportion of individuals who were physically active during leisure time, was significantly lower among the subjects with impaired glucose tolerance (8‐1% vs 19‐7%; P<0–05). Moreover these subjects had a higher heart rate during and 1 min after the standard exercise test (113‐4±15‐8 vs 105‐7±17‐7 beats/min, P<0–005; mean±SD).This supports the hypothesis that low physical activity is a risk factor for impaired glucose tolerance, independent of mutual effect of obesity.
A simplified technique for measurements of energy expenditure and substrate oxidation in man
Authors: Lindmark Lars , Ekman Lars , Lundholm Kent 
Published: April 2008

Summary. A technique is described for simultaneous measurements of energy expenditure and oxidation of exogenous substrates in man. The equipment comprised a semi‐opened respiratory hood operated by a negative‐flow pressure of the gas flow through the system. The system was constructed by assembling commercially available components with high analytical precision into an integrated constellation. We present results of instrument accuracy, assessed by calibration, and the coefficient of variation (CV) for calibration procedures of the total system, as well as findings with regard to the degree of reproducibility of applied investigations on both healthy volunteers and hospitalized patients.The overall coefficient of variation was 3–4% of the mean values for RQ and energy expenditure. This includes both biological and methodological variation. The cost of this system is less than that for a commercially available system with a similiar performance.
Mild mental stress in diabetes: changes in heart rate and subcutaneous blood‐flow
Authors: Hildebrandt Per , Mehlsen Jesper , Sestoft Leif , Nielsen Steen Levin 
Published: April 2008

Summary. A TV‐game of tennis of 20 min duration was used to study the influence of mild mental stress on subcutaneous blood‐flow (SBF), blood‐pressure and heart rate in nine insulin‐dependent diabetics and nine healthy subjects. SBF was measured on the thigh by local clearance of xenon‐133. Measurements were made before, during and after the period of stress.During stress, SBF increased significantly by 26% in the healthy subjects, while SBF remained unchanged in the diabetics. The difference between the two groups was significant (P<0–05). Following stress, SBF returned to pre‐stress level in the healthy subjects, while a significant decrease of 33% was observed in the diabetics.The pre‐stress heart rate level was higher and the stress‐induced increase in heart rate was less in the diabetics compared with the healthy subjects (P<005). During the stress a slight–but insignificant–increase in blood‐pressure was observed in both groups.In conclusion, we found that even mild mental strain influences SBF in both normal subjects and in diabetics. The induced alterations in the two groups are different, probably because of a slight parasympathetic dysfunction in the diabetics.
Intercrural differences of arterial blood‐pressure and blood‐flow in new‐born infants
Authors: Lassvik C. , Wesstrom G. 
Published: April 2008

Summary. Intercrural systolic blood‐pressure differences did not exceed 10 mmHg in 22 healthy infants who were term, pre‐term or small for their gestational age (three); as measured simultaneously in both legs with 3‐cm wide thigh cuffs and mercury‐insilastic strain gauges around the calves. In 13 infants with indwelling umbilical artery catheter and normal angiographic findings in both legs, blood‐pressure differences were similarly low in a majority of the infants, but in three of these intercrural differences of 15–20 mmHg were found. Resting and submaximal arterial leg blood‐flow, measured with venous occlusion plethysmography, showed larger intercrural differences than blood‐pressure, and did not add further information.The results indicate that simultaneous systolic blood‐pressure measurements in the legs, with strain gauge plethysmography, is a simple and risk‐free noninvasive method, suitable, for example, for diagnosing thromboembolism in infants. An indwelling umbilical artery catheter seems to interfere very little with the arterial circulation in the catheterized leg.
Follow‐up of circulatory changes secondary to deep venous thrombosis with special regards to radionuclide tests
Authors: Edenbrandt C. M. , Nilsson J. , Ohlin P. 
Published: April 2008

Summary. The influence of circulatory changes, which are secondary to deep venous thrombosis (DVT) in the leg, on result of radionuclide tests was studied in eight patients. Strain gauge plethysmography, a radionuclide blood‐pool test and phlebography were performed both in the acute phase and during recovery up to 6 months after the initial admission. Morphological and functional changes were correlated with results from repeatedly performed 99Tcm‐plasmin tests, a test currently used for diagnosis of DVT.In the acute phase, the thrombotic leg showed an increase in pooled blood and, in the case of proximal thrombosis, also impaired venous outflow. During the 6‐month follow‐up complete recanalization was observed in three patients and partial recanalization in five. The circulatory changes were found to recover progressively and earlier than the morphological changes.The 99Tcm‐plasmin test was pathological at admission in all patients. It was normalized in parallel with plethysmography and blood‐pool test results, at a time when morphological recovery was still incomplete. These findings confirm that a positive 99Tcm‐plasmin test reflects haemodynamic changes which are secondary to the DVT rather than a specific binding of the radiopharmaceutical to the thrombus. The 99Tcm‐plasmin test was normalized from 1 to more than 26 weeks after an acute DVT. This finding is of practical importance when using radionuclide tests for evaluation of acute recurrent DVT.
Haemodynamics during repeated exercise tests with special reference to the ‘warm‐up’ phenomenon in patients with angina pectoris
Authors: Westheim A. , Grendahl H. , Kjekshus J. , Sivertssen E. , Refsum H. E. 
Published: April 2008

Summary. The haemodynamic effect of two successive supine exercise tests 20 min apart was examined in 12 patients with angina pectoris. All the patients had coronary artery disease verified by angiography and were accepted for coronary bypass surgery. They exercised 20–40 W and all of them had angina during the first exercise test. Half the patients did not experience angina during the second of the two exercise tests (‘warm‐up’ responders). In these patients left ventricular filling pressure (LVFP) was reduced by 40% (P<0·01) in the second compared to the first exercise test. The non‐responders showed no significant change in LVFP. The heart rate pressure product (RPP) and thus myocardial oxygen demand were unchanged in responders and non‐responders.In another 10 patients with angina and coronary artery disease, also accepted for coronary bypass surgery, atropine (1·5—2·0 mg) was given intravenously. Ten minutes after administration of atropine, these patients followed exactly the same investigation programme including two successive supine exercise tests as in the group not given atropine. In the group given atropine, four ‘warm‐up’ responders and six non‐responders showed the same pattern of response in LVFP as in the group not given atropine. In the ‘warm‐up’ responders a smaller increase in RPP was observed during the second exercise test compared to the first. The present study indicates that cholinergic mechanisms are probably not involved in the ‘warm‐up’ phenomenon.Due to the difference in haemodynamic response, the ‘warm‐up’ phenomenon has to be taken into account when evaluating results from haemodynamic studies of cardiovascular drugs.
Nuclear ejection fraction measurements with a small crystal detector: methodological investigations
Authors: Brodin L. Å. , Boney D. E. 
Published: April 2008

Summary. A series of studies were performed with a single crystal detector system, nuclear stethoscope (N.S.) (Bios®) used for measuring left ventricular function (ejection fraction [EF]). Counting capacity, validity, reproducibility, effect of repositioning of the instrument and of different operators were investigated.Counting capacity was found to be approximately linear up to a count rate of 40,000 cps.Validity was studied by comparing measurements in the same subject using the N.S. with those obtained by a gamma‐camera computer system with software using a background subtraction similar to that in the N.S. The mean difference in EF (0·01) was not significant. Maximum emptying and filling velocity measurements with the two instruments were also compared r= 0·86 and r= 0·89, respectively, and a coefficient of variation of 18·1% and 17·9%.Reproducibility was determined from duplicate determinations under identical conditions. The standard error of a single determination was 5%.Repositioning by the same operator increased the variation to 9·1% without any systematic difference. Comparison between two operators did not increase the coefficient of variation (8·8%). There was a systematic difference between measurements using the two acquisition modes, ventricular function mode and position monitor mode.Beat‐to‐beat variation of EF values during 12 s in 25 patients with coronary heart disease studied under standardized resting conditions was 11·9%.
The effects of cortisol supplementation on the metabolic and hormonal response to surgery
Authors: Lacoumenta S. , Yeo T. H. , Burrin J. M. , Paterson J. L. , Hall G. M. 
Published: April 2008

Summary. The role of Cortisol in determining the metabolic and hormonal changes associated with a standardized surgical operation was investigated. Twelve patients undergoing pelvic surgery were studied. Six received steroid supplementation with an infusion of hydrocortisone sodium succinate at a rate of 8 mg/h for 24 h, together with 1·5 g hydrocortisone acetate intraperitoneally at the completion of surgery, while the remainder acted as a control group.Steroid supplementation resulted in plasma Cortisol values in the range 1913–2265 nmol/1 from 4 to 24 h after the start of surgery. However, this marked hyper‐cortisolaemia had no significant effects on circulating metabolites other than glucose, and did not alter plasma ACTH, GH and insulin values. The usual glycaemic response to surgery was significantly augmented by 1·0–1·5 mmol/1 in the cortisol group. We conclude that changes in substrate mobilization observed after cortisol administration in normal volunteers may not accurately predict the effects found after surgery, when catabolic hormones and other modulators such as interleukin‐1 may influence metabolism.
Blood flow, substrate utilization and heat generation in tissues drained by the azygos vein in man
Authors: Brundin T. , Hagenfeldt L. , Söderberg R. , Wahren J. 
Published: April 2008

Summary. The present study was undertaken to examine the blood flow, heat generation and substrate utilization in tissues drained by the azygos vein in healthy subjects. Catheters were inserted percutaneously into the azygos vein and the pulmonary artery in 10 healthy male subjects in the basal, post‐absorptive state. Blood flow in the azygos vein was measured by thermodilution technique, blood temperature was recorded in both the azygos vein and the pulmonary artery and blood samples for the determination of oxygen content and substrate concentrations were collected from both vessels repeatedly at timed intervals. Free fatty acid (FFA) exchange was evaluated following the intravenous infusion of 14‐C labelled oleic acid.The average azygos vein blood flow was 94 ± 10 ml/min. The coefficient of variation for the flow determination was 3·6%. The blood temperature in the azygos vein was consistently higher than that in the pulmonary artery, indicating an average calculated net heat production in the tissues of 0·5 W. The oxygen uptake to the tissues drained by the azygos vein amounted to 6 ± 1 ml/min. Significant amounts of glucose, FFA and ketone bodies were taken up in the azygos area, while both glycerol and FFA were released. The FFA uptake could, if oxidized, account for about half of the oxygen uptake.In conclusion, the findings indicate that, in the basal state, the tissues drained by the azygos vein utilize both glucose and FFA. Heat is generated within the area but the rate of generation is low and can largely be explained by the oxidative metabolism. The findings do not support an important role for brown adipose tissue metabolism in the interscapular region in man.
Measurement of global and regional left ventricular performance with isotope technique in coronary heart disease
Authors: Boström P.‐Å. , Svensson M. , Lilja B. 
Published: April 2008

Summary. In order to evaluate the left ventricular function in coronary artery disease, radionuclide measurements of global and regional ejection fraction (EF), regional wall motion and phase analyses of the left ventricular contraction were performed by equilibrium technique. One group of patients with angina pectoris and one group with myocardial infarction were compared with a control group. All the above‐mentioned parameters significantly separated the infarction group from the reference group both at rest and during work, while the group of patients with angina pectoris showed disturbances mainly during work, such as impaired ability to increase global and regional ejection fraction and regional wall motion.Adding regional analysis and phase analysis to the global EF determination increases the possibility of studying the left ventricular function. However, this addition has a limited value in detecting impaired left ventricular function compared to the determination of just global EF in patients with angina pectoris and in patients with myocardial infarction.