bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kidney, lower limb and whole‐body uptake and release of catecholamines in alcoholic liver disease
Authors: Henriksen J. H. , Ring‐Larsen H. , Christensen N. J. 
Published: April 2008

SummaryRegional (kidney, lower limb) and whole‐body kinetics of endogenous noradrenaline (NA) and tritium‐labelled L‐noradrenaline (3H‐NA) were determined in patients with alcoholic liver disease (one alcoholic hepatitis, 12 cirrhosis) and in control subjects (n= 6) in order to get information on the sympatho‐adrenal system in liver disease. Arterial NA was significantly elevated in ascitic patients (median 2·5 nmol/1, n = 9, P<0.05) as compared to non‐ascitic patients (1·6 nmol/1) and controls (1·7) nmol/l). NA spillover per unit NA inflow was increased in the kidney in patients with ascites (0·69 vs. 0·45 pmol/ming per pmol/min‐g in controls, P<0.005) but not in the lower limb (0·23 vs. 0·49 in controls, P<0·01). In patients with ascites the spillover rate of NA from the kidney into plasma (1·9 pmol/min·g) was significantly increased (P<0·02) compared to controls and non‐ascitic patients (1·2 and 1·0 pmol/min·g, respectively. Patients and control kidneys and limbs extracted almost the same fraction of 3H‐NA (0·34 vs. 0·32NS and 0·34 vs. 0·37 NS, respectively). Whole‐body clearance of 3H‐N A was not significantly different in cirrhotics and controls (median 0·89 vs. 0·91 1/min·m2), indicating that the raised NA in decompensated cirrhosis reflects enhanced sympatho‐adrenal activity rather than decreased metabolism of this amine. Our results do not point towards a uniform sympatho‐adrenal overactivity in decompensated cirrhosis, but rather indicate regional differences with different order of NA spillover. The renal sympathetic overactivity, as indicated by the increased renal NA overflow, is likely to be important to the decreased renal perfusion and increased saltwater retention characteristic of this clinical condition.
Myocardial turnover of plasma free fatty acids during angina pectoris induced by atrial pacing
Authors: Kaijser L. , Ericsson M. , Walldius G. 
Published: April 2008

SummaryMyocardial extraction of free fatty acids (FFA), together with glucose, lactate, pyruvate, glycerol and oxygen was determined by simultaneous sampling of blood from an artery (a) and the coronary sinus (cs) at rest and during chest pains induced by atrial pacing in seven fasting male patients with ischaemic heart disease. Results were compared to those, at rest and during pacing at heart rate 140 beats min‐1in ten healthy men of similar age. A continuous i.v. infusion of14C oleate and3H palmitate enabled the calculation of simultaneous myocardial uptake and release of FFA. as well as of the fraction of extracted FFA which underwent direct oxidation. During chest pain lactate net extraction decreased to become, in some patients, negative. FFA extraction, as estimated from the fractional extraction of labelled fatty acid was likewise decreased, while the a‐cs O2difference was not significantly altered. The fractional oxidation of extracted FFA was increased, whereas the calculated fatty acid release from the heart was unaltered. The increase in fractional oxidation was quantitatively correlated with the decrease in lactate extraction suggesting that it was related to the degree or extent of ischaemia. It was also proportional to the decrease in FFA extraction. Thus, in patients with angina pectoris the ischaemic myocardium may be subjected to a limitation not only with regard to oxygen but also substrate flux into the myocardial cells.
The role of the endothelium in the control of venous tone: studies on isolated human veins
Authors: Thulesius O. , Ugaily‐Thulesius L. , Neglen P. , Shuhaiber H. 
Published: April 2008

Summary. The role of the endothelium in the vasomotor control of veins was investigated in 14 isolated ring preparations of presumably normal saphenous veins obtained from vein grafts in connection with vascular surgery. The investigations were performed with the specimens mounted for recording isometric tension in organ baths. Paired rings were used, one normal and the other de‐endothelialized by gentle rubbing. The responses to noradrenaline (10‐8‐2 × 10‐5M), acetylcholine (10‐6M) and 120 mM KCI solution were tested.After precontraction with 10‐7M noradrenaline, acetylcholine at 10‐6M did not induce cholinergic relaxation, but in the majority of experiments induced a further increase in tone. Maximal contraction with noradrenaline was significantly higher in normal compared to de‐endothelialized vessels. Therefore, endothelium‐derived relaxation as in arteries did not occur in human saphenous veins and the existence of an endothelial‐derived contracting factor in response to acetylcholine and noradrenaline is a possibility.
Body composition measurement by dual photon absorptiometry: comparison with body density and total body potassium measurements
Authors: Hassager C. , Sørensen S. Sølvsten , Nielsen B. , Christiansen C. 
Published: April 2008

Summary. Body composition was measured in 29 healthy adults (12 men and 17 women) by three different methods: Dual photon (153Gd) absorptiometry (DPA), body density measurements (BD) and measurements of total body potassium (TBK).Correlation and regression analysis with the body fat percentage (Fat%) measured by the three different methods gave r values between 0·83 and 0·90 and SEEs between 4·0 and 6·0 (Fat%). We conclude that DPA provides a new method of measuring body composition with precision and accuracy errors in the same range as the more established methods.
Measurement of carboxyhaemoglobin by spectrophotometry and gas chromatography
Authors: Johansson M. B. , Wollmer P. 
Published: April 2008

Summary. The purpose of this study was to evaluate state‐of‐the‐art spectrophotometry for measurement of carboxyhaemoglobin (COHb). We measured the fractional concentration of COHb in 109 blood samples from patients under investigation of anaemia or with exposure to carbon monoxide (smokers) with the OSM3 Hemoximeter and by gas chromatography. Duplicate measurements were made with both methods in 42 samples.We found only a trivial systematic difference between the two methods. There was, however, a considerable scatter of the measurements, the limits of agreement (95% confidence limits for the difference between the two methods) being —0.98 and 0.86% COHb. The poor agreement between the methods was largely explained by a large random scatter in duplicate spectrophotometric measurements, whereas the method based on gas chromatography was highly reproducible.We conclude that the low accuracy of spectrophotometric measurements of COHb precludes its use for assessment of the endogenous production of CO, but that it may be useful for assessment of exposure to exogenous CO.
Meal‐induced thermogenesis in previously obese patients
Authors: Thörne A. , Näslund I. , Wahren J. 
Published: April 2008

Summary. Meal‐induced thermogenesis is reported to be reduced in obese patients and the purpose of this study was to find out whether thermogenesis after a mixed meal differs between previously obese(post‐obese) subjects and non‐obese controls. Nine post‐obese patients (body mass index 27 ±1) and nine age‐ and sex‐matched non‐obese volunteers (body mass index 22 ±1) were studied with continuous indirect calorimetry in the basal state and after the ingestion of a standardized test meal. Following treatment with vertical banded gastroplasty for the obesity, the weight of the patients had decreased by an average of 44 ± 5 kg.Basal oxygen uptake and energy expenditure did not differ between the post‐obese and the controls. After the meal, energy expenditure increased rapidly, becoming relatively constant after 60 min; the average increase above basal was in the post‐obese 30·5 ± 1·8% and in the non‐obese controls 29·5 ±2·3% (NS). In absolute terms, the increments above basal were also similar in the two groups. The heart rate was higher in the post‐obese group throughout the study period.It is concluded that the thermogenic response to a mixed meal is much the same in post‐obese subjects and in non‐obese controls. These findings support the notion that a decreased meal‐induced thermogenesis is a secondary phenomenon rather than a primary pathogenic factor in human obesity.
Lung function in patients with prior poliomyelitis
Authors: Borg K. , Kaijser L. 
Published: April 2008

Summary. Lung volumes and spirometric flows, maximal respiratory pressures, lung diffusion capacity and blood gases were evaluated in 20 patients with prior poliomyelitis and compared with data from an age‐ and sex‐matched control group. In the polio patients, static lung volumes and pulmonary flow capacity were significantly reduced to approximately 65% of the values of the control group. However, expiratory and inspiratory flows were normal in relation to lung volumes, while maximal respiratory pressures were significantly reduced in the polio patients. Static lung volumes and forced flows were correlated with the maximal respiratory pressures both in the polio patients and in the controls. However, when the muscle force in the polio patients decreased below a certain level, it became more important as a determinant of lung‐flow capacity. The polio patients had a significantly increased Pco2 but a normal oxygen saturation and Pco2 was inversely correlated with the maximal respiratory pressures in the patients but not in the controls. The lung diffusion capacity was reduced in the polio patients compared to the controls, but less markedly than vital and total lung capacity.The findings indicate a restrictive respiratory dysfunction and alveolar hypoventilation most probably due to weakness of the respiratory muscles.
Is central chemoreceptor sensitive to intracellular rather than extracellular pH?
Authors: Lassen N. A. 
Published: April 2008

Summary. The chemosensitive area on the ventral surface of the brain stem responds to local acidosis by eliciting hyperventilation and to local alkalosis by hypoventilation. The stimulus is conventionally thought to be the hydrogen ion concentration in the area's extracellular fluid. It is pointed out, however, that the elegant studies by Loeschcke & Ahmad have demonstrated that [pH]c and [pH]i are normally tightly and rapidly coupled (Loeschcke & Ahmad, 1980). For this reason, the stimulus might just as well be the intracellular hydrogen ion concentration in the chemoreceptor area.The administration of acetazolamide allows the dissociation of [pH]c from [pH]i. With acetazolamide a sharp acid shift of CSF pH ([pH]c) is measured and in consonance with this shift a marked increase in CBF is seen. Comparing these two reactions to that obtained with CO2 breathing, it is apparent that 7% CO2 causes about the same decrease in [pH]c and the same increase in CBF. In other words CBF acidosis can quantitatively account for the CBF increase induced by acetazolamide. But CO2 and acetazolamide influence [pH]i quite differently, as CO2 drops [pH], to almost the same extent as [pH]i, while two recent studies by MR spectroscopy have shown that acetazolamide does not drop [pH]i measurably, if tissue hypercapnia is prevented in artificially ventilated rabbits or by the mild spontaneous hyperventilation caused by acetazolamide in normal man.The lack of measurable intracellular acidosis with acetazolamide accords with the very mild hyperventilation seen in man: the very high gain of the chemoreceptor response means namely that the approximate 10% drop in end‐expiratory Pco2 seen in man should result from a local acid shift of only 0·002 pH units, a shift much too small to be measurable by the technique used. If, on the other hand, [pH]c were the chemoreceptor stimulus, then it is surprising that 2 g of acetazolamide did not cause the same many‐fold increase in alveolar ventilation as 7% CO2, as the [pH]c acid shift is practically the same for the two stimuli.The [pH]c and [pH]i values referred to stem from global measurements. But the data regarding blood flow and Pco2 of the chemoreceptor area combined with histological evidence suggest that the acid‐base balance extra‐ and intracellularly of the area is just as for the brain as a whole. Therefore, the simplest hypothesis explaining the dissociation of the responses to CO2 and acetazolamide with respect to ventilation and to [pH]i is to assume that it is [pH]i and not [pH]c that is the chemoreceptor stimulus.
Respiratory variability and associated cardiovascular changes in adults at rest
Authors: van den Aardweg J. G. , Karemaker J. M. 
Published: April 2008

Summary. Breathing patterns and associated circulatory fluctuations may reflect the action of various regulatory mechanisms as well as mechanical influences of breathing on the circulation. Thus, the study of such patterns can enhance our knowledge of these mechanisms, both in normal and pathological conditions. In this review, literature is evaluated that provides insight into the breath‐to‐breath variation of respiration in quietly breathing adults. Also when respiration is seemingly random, deterministic patterns in the respiratory variability can often be discerned. The various methods used in the recognition of such patterns and their possible interpretation are discussed.Furthermore, the question is addressed how respiratory variability can affect the circulation and how this can be studied by analysing the time relationships of respiratory and circulatory parameters. This may add to both the understanding of normal cardiovascular regulation and to insight into cardiovascular disturbances under unstable respiratory conditions. As examples of such circumstances, some common conditions are discussed that are often, though not always, associated with pathology, viz. Cheyne‐Stokes respiration, snoring and the sleep apnoea syndrome.
Low‐frequency transcutaneous nerve stimulation in mild/moderate hypertension
Authors: Kaada B. , Flatheim E. , Woie L. 
Published: April 2008

Summary. Low‐frequency peripheral nerve stimulation may induce widespread cutaneous and muscular vasodilatation in animals and humans due to sympatho‐inhibition. This response has in humans been shown to be associated with a lowering of the systemic vascular resistance and arterial pressure.In the present study the effectiveness of low‐frequency (2 Hz) transcutaneous electrical nerve stimulation (TNS) has been examined in 46 patients, all 41–43 years of age, with a primary diagnosis of uncomplicated mild/moderate hypertension (90–115 mmHg diastolic pressure). The study was designed blind with matched controls in a TNS group and a placebo group. The blood pressure was measured objectively with an automatic monitor. In a short‐term experiment TNS produced a significant lowering of systolic, mean arterial, and diastolic pressures amounting to 8 mmHg (P<0·01), 6 mmHg (P<0·01), and 4 mmHg (P<0·02), respectively. In a long‐term study, after 2 weeks of daily stimulation, a similar depression was recorded with no stimulation on the day of examination. An eventual clinical use of the depressor effect of TNS demands further clinical research.
Evaluation of the dynamic cutaneous post‐ischaemic hyperaemia and thermal response in elderly subjects and in an area at risk for pressure sores
Authors: Schubert V. , Fagrell B. 
Published: April 2008

Summary. The response of skin blood cell flux (SBF) to locally applied pressure was evaluated with the laser‐Doppler technique in the areas of the sacrum and the gluteus maximus muscle of geriatric patients and healthy young and elderly subjects.The SBF over the sacrum stopped at a lower external skin pressure than over the gluteus muscle in all groups studied (P<0·05·0·001). The SBF at rest was lower among geriatric patients and over the sacrum, with men showing the lowest value (P<0·001). The initial slope of the SBF curve and the peak SBF during the post‐occlusive reactive hyperaemia (PRH) were lower among geriatric patients compared to younger healthy subjects (P<0·05·0·01) over both areas studied. During the last part of the PRH response rhythmic oscillations started, known as vasomotion.The mean skin temperature at rest was higher over the sacrum (P<0·001) than over the gluteus area, but no difference was found between the groups. The temperature increase during the PRH was larger over the gluteus muscle (P<0·01) than over the sacrum area in the healthy subjects. Among the patients the temperature increase was larger over the gluteus only during the first half of the PRH, after which the temperature increased most over the sacrum.It is concluded that SBF and skin temperature show different responses in microvascular reactivity to external pressure in elderly vs. younger subjects and also between sexes. The described technique may be useful in clinical practice for predicting the risk of pressure sores in different areas and subjects.
The effect of forced expirations on mucociliary clearance in patients with chronic bronchitis and in healthy subjects
Authors: Mortensen J. , Jensen C. , Groth S. , Lange P. 
Published: April 2008

Summary. Animal studies have shown that frequent coughing may damage the mucociliary apparatus in flow‐limiting segments of the central airways. To determine whether mucociliary clearance in humans is affected by repeated dynamic compression associated with forced expirations, we measured pulmonary deposition and mucociliary clearance for 2 h of inhaled [99Tcm]albumin. The subjects inhaled [99Tcm]albumin on 2 study days (randomized) using (A) slow inspirations and forced expirations, while inhalation using (B) forced inspirations and slow expirations served as control. The study was conducted using 10 patients with chronic hypersecretory/obstructive bronchitis and six normal subjects. We found that inhalation of [99Tcm]albumin by the two manoeuvres (A and B) resulted in similar patterns of aerosol deposition. There was no significant difference in retention of radioactivity in the central lung region at 1 h in the patients with chronic bronchitis after inhalation with manoeuvre A (102%) and with manoeuvre B (91.5%), or in the healthy subjects after manoeuvre A (74%) and manoeuvre B (77%). There was also no difference in the retention at 2 h or in overall mucociliary clearance in any of the groups.We conclude that dynamic compression in the central airways associated with forced expiration does not affect bronchial clearance in the airways of healthy subjects or in patients with chronic bronchitis.
Assessment of the composition of major body regions by dual‐energy X‐ray absorptiometry (DEXA), with special reference to limb muscle mass
Authors: Fuller N. J. , Laskey M. A. , Elia M. 
Published: April 2008

Summary Dual‐energy X‐ray absorptiometry (DEXA) has been used to assess and compare the composition of whole body and major body regions in 12 female (weight, 56.9 ± 6–2 kg; BMI, 17.25 kg m‐2) and 16 male (weight, 73.1 ± 9–6 kg; BMI, 20.28 kg m‐2) healthy subjects. Standard deviations (and % coefficients of variation) of the differences between repeated measurements of fat ranged from 0.11 kg (9.0%) for arms to 0.42 kg (30%) for whole body; for arm bone mineral, 0.01 kg (2.0%), and for fat‐free soft tissue of the whole body, 0.42 kg (0.8%). Limb muscle mass was estimated using a new theoretical model of body composition, and the corresponding precision ranged from 015 kg (3.8%) to 0.27 kg (1.5%) for arms and total limb muscle mass, respectively.Proportions of each region consisting of fat were greater in females than in males (range, 20.31% vs. 16.18%), respectively, but the ratio of trunk to leg fat was lower (34:49% vs. 46:38%, respectively). Regional proportions of bone were similar between the sexes (all in the range 2.9–5.6%, for both females and males).Mean total limb muscle masses were 14.2 kg (arms, 2.8 kg; legs, 11.4 kg) for females and 22.2 kg (arms, 4.8 kg; legs, 17.4 kg) for males, which were 33.6% and 36.0% of fat‐free mass, respectively. The correlation coefficients between limb muscle (DEXA) and other indices of muscle mass were: for DEXA vs. total body potassium, 0.90 (SEE 1.1kg muscle mass) to 0.94 (1.6 kg); and for DEXA vs. anthropometry, 0.43 (1.2 kg) to 0.85 (1.3 kg). Those for limb volume (DEXA) vs. anthropometric volume, 0.91 (0.78 1) to 0.94 (1.91 1).It is concluded that DEXA enables the valid and reproducible estimation of fat, fat‐free soft tissue, bone, and limb muscle mass.
Planar 201T1 scintigraphy in ischaemic heart disease: a critical re‐evaluation of qualitative and quantitative data analysis
Authors: Pedersen F. , Rabøl A. , Sørensen S. S. , Høilund‐Carlsen P. F. , Madsen J. Kyst , Efsen F. , Sandøe E. 
Published: April 2008

Summary. The aims of the present study were to examine the observer agreement of qualitative (visual) and quantitative (computer‐assisted) analysis of planar 201T1 imaging and to compare the diagnostic values of these methods in the detection of infarcted and exercise‐induced ischaemic myocardium. The study population comprised of 119 patients (aged 24–77 years) referred consecutively for stress thallium scintigraphy for either diagnostic reasons (n= 42, 35%) or for further evaluation of known coronary artery disease (CAD) (n= 77,65%).The interobserver agreement was low with the qualitative method and significantly higher with the quantitative method: Kappa‐values 0.29‐0.39 vs. 0.80‐0.92, P < 0.00001. Sensitivity and specificity for the detection of previous Q‐wave infarct was significantly higher with the quantitative method (94% and 94%) compared to the qualitative method (77% and 74%), P < 0.01. The corresponding predictive values of a positive and a negative test were 96% and 92% vs. 80% and 70% (P < 0.01).In 86 patients in whom coronary angiography was performed the two methods did not differ significantly regarding sensitivity, specificity and predictive values for the diagnosis of reversible ischaemia or rather CAD. However, when 22 patients with a maximal exercise heart rate < 80% of the predicted target heart rate were excluded the sensitivity was increased with both techniques and was significantly higher with the quantitative method.We conclude that qualitative image analysis has an unacceptably low reproducibility and that quantitative image analysis increases the diagnostic value of 201T1 scintigraphy considerably in both the detection of previous infarcts and, provided a sufficient exercise level is achieved, in the disclosure of reversible myocardial ischaemia.
Right ventricular pressure‐volume relations in chronic lung disease
Authors: Schrijen F. V. , Redondo J. , Henriquez A. H. , Chabot F. 
Published: April 2008

Summary. Thirty‐four patients with chronic lung disease in stable condition were studied at supine rest (RS), at rest with the legs raised (LR), and during two levels of exercise: El, 0 or 20 W, E2, 20 or 40 W. Five patients had normal spirometry (group 1), six patients had normal vital capacity but FEV1/VC below 70% (group 2), and 23 patients had VC below 95% of normal and FEV1/VC below 70% (group 3); group 3 was subdivided into group 3a (n= 14) without, and group 3b (n= 9) with a history of right heart failure (RHF).Right ventricular end‐diastolic (RVEDV) and end‐systolic (RVESV) volumes were computed from stroke volume and right ventricular ejection fraction (RVEF). RVEF at rest was correlated with lung function variables. Changes in RVEF from LR to E2 were normal, i.e. above 0.05, except for in group 3b, where RVEF did not increase with exercise. Relation between RVESV and pressure, and changes in stroke volume with RVEDV from LR to E2 were also abnormal in group 3b. These results show that in patients with chronic lung disease RVEF at rest reflects lung function, whereas its adaptation to exercise is impaired only in patients who have experienced RHF episodes.