bluuebunny/crossref_metadata_2025 huggingface dataset:
Early changes in blood‐brain barrier permeability after porto‐caval shunt and liver ischaemia
Authors: Crinquette Jacques‐François , Boschat Michèle , Rapin Jean‐Robert , Delorme Marie‐Louise , Opolon Pierre
Published: April 2008

Summary. The brain oedema, distribution space (DS) and brain uptake index (BUI), of l‐glucose, inulin, B12 vitamin and of three polypeptidic hormones of increasing molecular weight (angiotensin‐I, gastrin and insulin) were measured in the rat after sham operation, porto‐caval shunt (PCS) or liver ischaemia. At an early stage following PCS or liver ischaemia brain oedema was not constant, and was only demonstrable after liver ischaemia in a large number of animals. Substances without an active transport and with a low diffusion coefficient such as l‐glucose and inulin had a very low BUI, unchanged even if the 3H2O brain content or the DS were modified. B12 vitamin, DS and BUI were very high and did not change after liver ischaemia or PCS. Insulin DS and BUI were low in the three groups of animals, whereas it decreased after PCS for gastrin.

A significant increase of BUI and DS (without any cerebral oedema) was demonstrated for angiotensin‐I, a polypeptidic hormone of molecular weight 1300. This polypeptidic marker is in the same range of MW as the preliminary recently recognized medium‐sized molecules which may be involved in the pathogenesis of encephalopathy during experimental acute liver failure. However, not only the MW, but the nature of such polypeptides may be of importance in the genesis of this limited impairment of BBB permeability.
Measurement of stroke volume with impedance cardiography
Authors: Milsom Ian , Sivertsson Ramon , Biber Björn , Olsson Torsten
Published: April 2008

Summary. Simultaneous determination of stroke volume with impedance cardiography and the dye dilution technique was compared in 11 healthy men before and after exercise. The correlation coefficient for all measurements was 0·82. Mean stroke volume determined by impedance cardiography was significantly (P<0·001) lower than mean stroke volume calculated by the dye dilution technique. However, there was no significant difference in the mean change in stroke volume determined by the two techniques during serial measurements. The reproducability of single impedance‐determined stroke volumes (6·9 ml) was not significantly different from single values obtained by dye dilution (7·3 ml).

Impedance cardiography was found to be a safe, reliable, non‐invasive method for the measurement of changes in stroke volume in healthy individuals before and after exercise. At present, direct estimation of absolute values of stroke volume is not recommended using impedance cardiography. Calibration of the impedance technique against other established techniques in a given application is necessary.
The effect of temperature, ischaemia and contractile activity on the relaxation rate of human muscle
Authors: Wiles C. M. , Edwards R. H. T.
Published: April 2008

Summary. The relaxation rate from electrically stimulated isometric contractions of human adductor pollicis has been measured during rewarming following cooling, during ischaemia and during ischaemic contractile activity. The Q10 for relaxation rate (25–37°C intramuscular temperature) was estimated as 2·3. Relaxation rate was found to decline at a rate of 1·5% initial value per minute of ischaemia. Relaxation rate declined more rapidly during ischaemic contractile activity than during ischaemia alone. The rate of decline was more closely related to the force × time performed than the number of excitatory impulses. During a supramaximal 20 Hz tetanus, relaxation rate declined markedly at a time when only slight force fatigue had occurred; hence the decline could not be explained by selective fast muscle fibre fatigue. No recovery occurred during ischaemic rest following ischaemic activity but, following restoration of the circulation, recovery occurred with a half time of one minute being virtually complete at 5–7 min.

Changes in relaxation rate during fatiguing contractions and recovery from them follow different time courses from muscle excitability and force production. Change in relaxation rate cannot be simply related to changes in the concentration of major energy metabolites. It is proposed that relaxation rate is related to the rate of energy turnover in the contracting muscle.
Pre‐ and postoperative lung function in sitting and supine position related to postoperative chest X‐ray abnormalities and arterial hypoxaemia
Authors: Wirén J. E. , Lindell S. E. , Hellekant C.
Published: April 2008

Summary. Spirometry in both sitting and supine position was performed before and 3–5 days after elective upper abdominal surgery in 53 men, aged 41–72 years. The results were related to postoperative respiratory complications as defined by chest radiography and to measurements of the arterial oxygen tension. Preoperative total lung capacity (TLC), functional residual capacity (FRC) and wash‐out volume (WOV) were lower in both positions among patients who were to develop major chest X‐ray abnormalities than among patients with normal chest radiographs postoperatively. All patients who developed major chest X‐ray abnormalities had a negative value for FRC ‐ closing capacity (CC) in the supine position preoperatively, indicating ‘airway closure’ during tidal breathing. Preoperative WOV and lung clearance index (LCI) were higher in both sitting and supine positions in patients who developed postoperative hypoxaemia than in patients who did not. The postoperative decrease in TLC, FRC and WOV in the sitting position was greater among patients with major X‐ray abnormalities and/or arterial hypoxemia postoperatively than among patients without these complications.

According to our results, conventional spirometry in the supine position is not superior to conventional spirometry in the sitting position as part of pre‐ or postoperative assessment of patients. On the other hand, both preoperative ‘airway closure’ and arterial oxygen tension, measured in the supine position, showed a correlation with postoperative chest X‐ray abnormalities.
Heterogeneity of splanchnic vascular transit times in man
Authors: Winkler K. , Bass L. , Henriksen J. , Larsen O. Andree , Ring P. , Tygstrup N.
Published: April 2008

Summary. A new method of quantifying the heterogeneity of transit times through vascular beds, free from corrections for effects of recirculation, is applied to data of splanchnic transit times in eight normal subjects and three patients with cirrhosis and end‐to‐side portocaval shunts, as obtained by Bradley's method.

There is proportionality between the heterogeneity, expressed as standard deviation and the mean transit time in the eight normal subjects. The heterogeneity of plasma transit times is not appreciably larger than that of red blood cells, despite the larger volume of distribution of plasma. This may suggest that the large vessels contribute substantially to the dispersions of vascular transits in the entire splanchnic system. Pearson Type III distribution is proposed for the frequency function of the splanchnic transit times, and the power of the pre‐exponential factor is deduced for plasma and for red blood cells. It is found that the initial splanchnic transits are dominated by plasma, this may be due to sequestration of red cells in the spleen. The heterogeneity of transit times in normals is not appreciably different from that in patients with cirrhosis and portocaval shunt, which suggests that the extra heterogeneity of the cirrhotic liver is of the same order as the heterogeneity of the normal extrahepatic splanchnic organs. The method may be a useful tool to describe heterogeneity of vascular transits in other organs.
Myocardial glutamate and alanine exchanges related to carbohydrate metabolism in patients with normal and stenotic coronary arteries
Authors: Thomassen Anne , Nielsen Torsten Toftegaard , Bagger Jens Peder , Thuesen Leif
Published: April 2008

Summary. Myocardial exchanges of glutamate, alanine, glucose, lactate, free fatty acids (FFA) and oxygen in resting state were determined in nine subjects (controls) without and in 28 patients with coronary artery disease (CAD).

Patients with CAD showed increased myocardial glutamate uptake (2·51±0·60 μmol/min) and alanine release (1·25±0·60μmol/min) compared to controls (glutamate uptake: 1·66±0·79 μmol/min; alanine release: 0·63±0·41 μmol/min). Myocardial glucose and lactate uptake was augmented in CAD patients, whereas FFA arterio‐venous differences were decreased in patients with three‐vessel‐disease.

The amount of glutamate taken up by the heart correlated positively to lactate uptake in all subjects (r= 0·84) and to external glucose utilization in patients with CAD (r= 0·72). Myocardial alanine release was positively related to glucose and lactate uptake in controls and in patients with only moderate CAD (one‐vessel‐disease). Glucose and FFA uptake correlated inversely in controls (r=0·84), but not in CAD patients.

A tight relation between exchanges of glutamate/alanine and carbohydrate metabolism in human heart is demonstrated. The data suggest altered myocardial substrate exchange towards augmented carbohydrate utilization in CAD patients in resting state. The results agree with in vitro and animal studies suggesting extraction of glutamate from the circulation to be of importance for maintaining carbohydrate consumption in chronic ischaemic heart disease.
Water diuretic effect of intravenously administered 9‐deoxo‐16,16‐dimethyl‐9‐methylene‐PGE2 in conscious man
Authors: Leksell Lars G. , Christensen Niels J. , Vesterqvist Ole , Wallin Carl‐Johan
Published: April 2008

Summary. The stable prostaglandin analogue 9‐deoxo‐16,16‐dimethyl‐9‐methylene‐PGE2 (9‐methylene‐PGE2) was infused intravenously (0·5 ml/min) in the dosage of 20 μg/min for 2 h in conscious euhydrated man. The administration of 9‐methylene‐PGE2 rapidly induced an increase in urine flow (from 1·2±0·07 to 5·35±1·07 ml/min) concomitantly with a decrease in urine osmolality (from 827±40 to 193±44 mOsm/kg). Parallel to this tubular reabsorption of sodium (Naf), calcium (Ca2+) and magnesium (Mg3+) increased and that of potassium (K+) decreased as shown by a reduction in the clearance for respective ion divided by the clearance of inulin. Apparently the water diuresis was mediated by an inhibition of arginine vasopressin's (AVP) antidiuretic effect. The mechanism behind the increase in renal tubular reabsorbtion of Na+ could possibly be a 9‐methylene‐PGE2 mediated modulation of the renal aldosterone effect. However the protocol followed did not provide any evidence for this, or any other explanation of the observed renal retention of Na+, Ca2+ and Mg2+. The results reported here indicate that 9‐methylene‐PGE2 may have a future use as a water diuretic agent in patients suffering from water retention and dilutional hyponatraemia such as seen in the syndrome of inappropriate antidiuretic hormone (AVP) release commonly known as SIADH or Schwartz‐Bartter's Syndrome.
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.
Influence of somatostatin on splanchnic haemodynamics in patients with liver cirrhosis
Authors: Eriksson Ljusk Siw , Law David H. , Sato Yuzo , Wahren John
Published: April 2008

Summary. The influence of intravenous somatostatin infusion (7·6 μag/min) on systemic and splanchnic haemodynamics was examined in 10 patients with liver cirrhosis and portal hypertension. The hepatic vein catheter technique was employed and indocyanine green dye was injected to evaluate hepatic blood flow. Mean wedged hepatic venous pressure fell from 24·9±2·8 in the basal state to 21·4±3·2 mmHg (P<0·2) at 60 min of infusion and the mean arterial pressure decreased from 87±5 to 80±6 mmHg (P<0·05). The rate of indocyanine green dye disappearance decreased from 8·7± 1·9 to 6·6±1·7 %/min (P<0·00l) during the infusion, indicating decreased hepatic blood flow. Arterial‐hepatic venous oxygen differences rose from 69±11 to 78±11 ml/l. Blood glucose levels fell from 4·84±0·31 to 3·79± 0·33 mmol/l at 60 min of infusion (P<0·005). It is concluded that a continuous infusion of somatostatin in patients with liver cirrhosis and portal hypertension causes a decreased hepatic blood flow with augmented hepatic oxygen extraction and a modest reduction in mean wedged hepatic venous pressure. In view of the magnitude of the observed haemodynamic changes the findings do not suggest an important role for somatostatin in the treatment of patients with bleeding oesophageal varices.
Subcutaneous measurements of133 Xe disappearance with portable CdTe(CI) detectors: elimination of interference from combined convection and diffusion
Authors: Bojsen Jørgen , Staberg Bent , Kølendorf Klaus
Published: April 2008

Summary. Portable, solid state, cadmium telluride [CdTe(C1)] detectors were used for measurements of 133Xe‐disappearance rate constants as a measure of subcutaneous (s.c.) blood flow. To eliminate the disturbance on the measurements from combined local convection and diffusion of xenon in the s.c. tissue, two methods were demonstrated to be feasible in both control persons and anaesthetized rabbits. A small volume (50–80 μ1) was injected into the s.c. tissue at a depth of 5 mm and the CdTe(C1) detector elevated 20 mm above the skin surface. In this situation identical disappearance rate constants were recorded by the CdTe(C1) detector and the Nal(T1) reference detector at 15–20 cm from the depot. Similar results were obtained when either a large volume ( 800 μ1 of Xe in humans) was injected into the s.c. tissue or the labelling was performed with a smaller volume in an atraumatic uniform manner to obtain a constant Xe concentration exceecling the field of view of the CdTe(C1) detector, which in these cases was attached directly to the skin surface. The coefficients of variation (CV) of the disappearance rate constants measured by the CdTe(C1) detector were 9% and 11%, and these values did not differ significantly from each other (P>0·2), or from CV‐values calculated from measurements with NaI(T1) detectors.
Total body bone mineral in vivo by dual photon absorptiometry. II. Accuracy
Authors: Gotfredsen Anders , Borg Jens , Christiansen Claus , Mazess Richard B.
Published: April 2008

Summary. We investigated the accuracy of total body mineral (Tbbm) measured by dual photon absorptiometry (1 Ci 153Gd source, 44 and 100 KeV) using skeletons, soft tissue equivalent materials and whole cadaver extremities. The accuracy was assessed on five skeletons (r=0·99, SEE=1·5%). The influence of the soft tissue composition on the TBBM measurement was investigated in the same five skeletons. They were scanned in a 16 cm thickness of ethanol solutions of different concentration (0, 20, 40, 60, 80, 100% ethanol) and only a 2% difference (non‐significant) was found between measuring 100% ethanol and 100% water. Furthermore, seven whole cadaver extremities were scanned before and after removal of the soft tissues (r=0·995, SEE=6·3%). The slope was not different from one and the intercept not different from zero. Equipment at the University of Wisconsin, Madison, and at Glostrup Hospital, Denmark, was compared by measuring the same healthy subjects and skeletons on both scanners. The Glostrup and Madison TBBM values correlated well (r=0·99, SEE=5·8%) and the intercept (345 Glostrup arbitrary units) was not significantly different from zero (P>0·05). The TBBM results were calibrated into total body calcium (TBCA) and no significant difference was found between Glostrup and Madison TBCA values (P>0·20).
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

The 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

Exercise 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

In 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

Functional 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.
The effect of intravenous prostaglandin E, on ischaemic pain and on leg blood‐flow in subjects with peripheral artery disease: a double‐blind controlled study
Authors: Jogestrand Tomas , Olsson Anders G.
Published: April 2008

Summary. The effect of intravenous PGE1 (15 μg/h for 72 h) and saline (placebo) on ischaemic resting pains and the macro‐ and microcirculation was studied in 16 patients with peripheral artery disease. No significant difference in pain relief was observed between PGE] and placebo. The calf blood‐flow was unchanged during both infusions. Skin temperature in the arteriosclerotic foot, however, increased significantly during PGE1 infusion but not during saline infusion. No significant effects were seen on blood‐pressure, fluorescein angiography or vital capillary microscopy of the big toe 1 week or 1 month after the PGE1 and placebo infusions.
Factors of importance in the hyperglycaemia induced by upper abdominal surgery
Authors: Rutberg Hans , Håkanson Erik , Jorfeldt Lennart
Published: April 2008

Summary. The variation in the hyperglycaemic response, between different individuals, is large in the immediate postoperative period. In the present study, factors of possible importance in the hyperglycaemic response to standardized elective surgery (cholecystectomy) were determined by stepwise multiple linear regression analysis. The statistical analysis comprised 29 variables which included hormones (catecholamines, Cortisol, insulin, thyroid hormones), blood‐borne energy metabolites (glucose, lactate, free fatty acids (FFA), glycerol, 3‐hydroxybutyrate, alanine) as well as anthropometric data and variables related to surgery and anaesthesia. In linear regression analysis, with one independent variable, the glucose concentration correlated significantly with: the duration of surgery, the dose of pancuronium bromide, the dose of fentanyl, the lactate, adrenaline and Cortisol concentrations respectively. The variables which, when successively included in stepwise regression, significantly reduced the residual variance for glucose were, in order of introduction; the duration of surgery and the Cortisol and adrenaline concentrations respectively. It is concluded that, in standardized surgical trauma the duration of surgery may influence the metabolic response to surgery. Duration of surgery has, thus, to be taken into account when interpreting results from studies where different treatments are compared. Our results confirm that there is a synergistic effect of Cortisol and adrenaline in mediating the hyperglycaemic response to surgery.
Does a computer‐based ECG‐recorder interpret electrocardiograms more efficiently than physicians?
Authors: Jakobsson Arne , Ohlin Per , Pahlm Olle
Published: April 2008

Summary. The quality of ECG‐interpretations by a computer‐based ECG‐recorder has been compared with those carried out visually by physicians in routine clinical practice. Independent reports have been analysed on 474 routine ECGs taken in the medical emergency and out‐patient departments, as well as in general practice. Computer reports were available for all of the ECGs, but the physicians had not annotated their interpretations in 11% of them. Eighty‐two per cent of the computer‐interpretations were adjudged as being satisfactory. The corresponding figure for the physicians' interpretations was 64%. The computer‐based ECG‐recorder was found to be better than the physician at interpreting ECGs.
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.
Beta‐blockade and binding of digoxin to skeletal muscle
Authors: Joreteg T. , Jogestrand T.
Published: April 2008

Summary. The effect of beta‐blockade and a 1‐h bicycle exercise test on the digoxin concentration in skeletal muscle (thigh) and serum was studied in 10 healthy men, who had ingested 0·5 mg digoxin daily for 2 weeks. Each subject performed two exercise tests at 100–140 W during maintenance digoxin treatment and 24 h after the latest dose. They rested in the supine position for 2·5 h before the exercise. Sixty minutes before the start of the exercise 0·25 mg/kg b.w. propranolol or saline (control) were injected (single‐blind). At the end of the exercise the mean heart rate was 30% lower with beta‐blockade (P < 0·001). During exercise the mean skeletal muscle digoxin concentration increased by 29% (P<0·01) in the control situation and by 12% (NS) with beta‐blockade. The results indicate that propranolol partly inhibits the exercise‐induced increase in skeletal muscle digoxin binding. This might be due to inhibition of a catecholamine‐induced stimulation of Na+‐K+ATPase during exercise.
Increased alveolar deadspace after closure of cardiac septal defects: pulmonary air embolism or failure of homeostasis?
Authors: Fletcher Roger , JöUgi Peeter
Published: April 2008

Summary. During surgery for closure of atrial or ventricular septal defects (ASD, VSD), we used a computerized on‐line system to follow changes in the alveolar deadspace fraction. We observed a large increase in the alveolar deadspace immediately following septal defect closure. No increase had been observed post‐cardio‐pulmonary bypass in children operated upon because of aortic or pulmonary stenosis, or in adults undergoing myocardial revascularization. The increase in deadspace is probably a result of the lung's failure to adjust to the large decrease in pulmonary blood flow following septal defect closure. An alternative cause for the finding, that of pulmonary artery air embolism occurring intraoperatively, appears to be less likely.
Clinical evaluation of impedance cardiography
Authors: Goldstein D. S. , Cannon R. O. , Zimlichman R. , Keiser H. R.
Published: April 2008

Summary. We tested the validity of thoracic impedance cardiography for measuring cardiac output in man by comparing absolute values obtained using the non‐invasive impedance method with values obtained using the invasive thermodilution method. We also compared per cent changes in cardiac output using impedance cardiography and thermodilution in response to environmental manipulations including cardiac pacing and intravenous administration of ergonovine, dipyridamole, or isoproterenol. Among 19 patients, absolute values for cardiac output, using the impedance and the thermodilution techniques, agreed well (r=0·85, P<0·001). The per cent change in cardiac output by impedance cardiography was positively correlated with the per cent change by thermodilution for the several manipulations (overall r=0·87, P<0·001). Impedance cardiography does appear, in general, to measure cardiac output and stroke volume validly in man, even in situations where heart rate and stroke volume change in opposite directions.
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%.
Relation between clinical and roentgenological scores and measures of lung function in cystic fibrosis, with special reference to pulmonary Xenon133 elimination
Authors: Ericsson A. , Strandvik B. , Troell S. , Freyschuss U.
Published: April 2008

Summary. Regional lung function (RLF) with Xenon133 was investigated in 40 patients with cystic fibrosis (CF) aged 5–28 years (mean 13) at 1–5 occasions during a 3‐year period. The RLF was determined with a 4‐collimator system and evaluated with a score based on the following parameters: (1) time of elimination of injected isotope and (2) of inhaled isotope, (3) regional ventilation, (4) regional perfusion and (5) ventilation‐perfusion ratios. The results were related to spirometry, X‐ray score (according to a modification of Chrispin and Norman) and clinical score (according to Shwachman and excluding X‐ray), which were all assessed in the same day. RLF correlated to clinical (P<0·01) and radiological score (P<0·01) and to residual volume (P<0·001) and the ratio between one second forced expiratory volume to vital capacity (FEV%) (P<0·01), but much higher correlations were found between X‐ray score, clinical score and different spirometric variables. We therefore conclude that RLF can be used in patients too young to cooperate in spirometry but that it is of less clinical value in older patients with CF.
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.
Lipoprotein lipase activity and intramuscular triglyceride stores after long‐term high‐fat and high‐carbohydrate diets in physically trained men
Authors: Kiens B. , Essen‐Gustavsson B. , Gad P. , Lithell H.
Published: April 2008

Summary. Men with regular physical training habits voluntarily increased their dietary fat intake from 43 to 54% of energy (E%) for four weeks. This was followed by a low‐fat (29 E%), high‐carbohydrate diet for another four weeks. During the high‐fat diet period, the muscle lipoprotein lipase activity (LPLA) increased from 59±8 to 106±12 mU/g (mean±SE) (P<0·05). After the high‐carbohydrate diet, LPLA was 57±16 mU/g, and unchanged relative to the pre‐trial value. The triglyceride content in m. vastus lateralis increased from 30±4 to 47±9 mmol/kg d.w. (P<0·05; mean±SE) following the high‐fat diet and to 41±8 following the high‐carbohydrate diet. Neither of the diets affected the serum triglyceride and insulin concentrations, nor glucose, glycerol, β‐hydroxybutyrate, citrate and lactate levels in the blood. Nor did they alter enzyme activities in muscle used as markers for the oxidative (citrate synthase, β‐hydroxy‐acyl CoA dehydrogenase) and glycolytic (glyceraldehyde phosphate dehydrogenase, lactate dehydrogenase) capacity. It is concluded that one month's adaptation to a high‐fat diet results in increased muscle‐LPL activity indicating a higher capacity for uptake of fatty acids from circulating serum triglycerides into the muscle cell in association with a greater capacity for triglyceride storage in the muscle. Under these conditions serum triglycerides were not decreased despite the increased muscle LPLA, and serum insulin variations could not explain the change in muscle LPLA. The effects of prolonged diets on muscle metabolism in well‐trained men differ in several respects from those of short‐term dietary treatments.
Effects of chronic sympathectomy on muscle fibre composition ISO‐myosin patterns, protein synthesis and calcium content in canine gracilis muscle
Authors: Karlsson J. , Cummins P. , Smith H. J. , Berggren P.‐O. , Saartok T.
Published: April 2008

Summary. We have previously reported functional and histological studies in five beagle dogs with unilateral lumbar sympathectomy. Three months later, fatiguability in the gracilis muscles was increased on the denervated sides, and this was associated with an increase in the relative distribution of FT fibres. Biochemical studies now show that these changes were associated with an increase in cytosolic protein without change in DNA content; this is consistent with an increase in cell size. There was a reduction in the proportion of slow myosin light chain isoforms from 50 ± 7 to 34 ± 6%. Noradrenaline levels were increased on the denervated sides but this may reflect greater vascularity. Calcium content did not correlate with fibre type but there was a positive relation with both noradrenaline content (r= 0·73; P<0·05) and DNA content (r= 0·84; P<0·05). It is concluded that sympathectomy induces several biochemical changes in skeletal muscle which constitute a change and increase in fast myosin light chain synthesis and a corresponding fibre type transformation.