bluuebunny/crossref_metadata_2025_split huggingface dataset:
Renal blood flow and metabolism after cold ischaemia: peroperative measurements in patients with calculi
Authors: Henriksen Jens H. , Petersen Hans K. 
Published: April 2008

Summary. Peroperative measurements of renal blood flow (RBF), renal O2,‐uptake, and renal venous lactate/pyruvate (L/P) ratio were performed before and after a period of 30–71 min of hypothermic (10–15°C) renal ischaemia in nine patients, undergoing surgery for renal calculi. Before ischaemia, RBF correlated inversely to arterial‐renal venous O2,‐difference (r = ‐0·74, P < 0·05, n= 9) and directly to the preoperatively estimated unilateral glomerular filtration rate (r = 0·76, P < 0·05, n= 8). After hypothermic ischaemia RBF decreased on the average by 42% (P < 0·01) immediately after re‐established perfusion and 36% (P < 0·02) 30 min later. In one additional patient, who had a short warm ischaemia (8 min), the flow pattern was the same. As arterial pressure remained constant, the reduced RBF signifies an increased renal vascular resistance. Renal O2,‐uptake and renal venous L/P ratio were almost constant, indicating no significant anaerobic processes being involved in the flow response. None of the patients showed any signs of reactive hyperaemia.It is concluded that hypothermic renal ischaemia may be followed by an increased renal vascular resistance even when signs of anaerobic metabolism are sparse or absent. This conception is in contrast to that gained from previous animal experiments where anaerobic processes are kept responsible for the changes. The mechanism behind the described response is unknown, but the changes are probably reversible.
Quantification of heart valve regurgitation: a critical analysis from a theoretical and experimental point of view
Authors: Wranne Bengt , Ask Per , Loyd Dan 
Published: April 2008

Summary. . A theoretical analysis is presented regarding factors of importance for the determination of distance of intrusion of the regurgitant jet in heart valve regurgitation. The analysis is based on hydrodynamic theory. In the idealized model situation, for a circular hole, the intrusion of the regurgitant jet is linearly related to the product of the fluid mean velocity in the orifice and the diameter of the orifice. This was also shown to be true in an experimental fluid model.Thus, volume regurgitation cannot be quantified by the measurement of distance of intrusion of the regurgitant jet alone. On the other hand, an estimate of volume regurgitation can, in the idealized situation, be obtained if mean fluid velocity in the orifice, distance of intrusion of the jet and regurgitation time are known.
The influence of transducer position on the M‐mode echocardiographic measurement of the left atrial dimension
Authors: Höglund C. 
Published: April 2008

Summary. Eighty‐five subjects were investigated to see if the left atrial dimension (LAD) determined by M‐mode echocardiography varies with different placements of the transducer in the parasternal long‐axis view. Satisfactory images from the third and fourth intercostal spaces were obtained in all subjects. A satisfactory image from the second, third and fourth intercostal spaces was obtained in 58 subjects and from the third, fourth and fifth intercostal spaces in 27 subjects.The mean LAD was significantly smaller (P<0–001) in the fourth intercostal space than in the third. The mean value obtained from the fifth intercostal space was smaller than that from the fourth.The beam pathway seen on the two‐dimensional echocardiogram indicates that the transducer should preferably be placed in the third intercostal space. If the transducer is placed in a lower intercostal space the measured left atrial dimension might be underestimated.
Splenic haemodynamics and portal hypertension in patients with liver cirrhosis and spleen enlargement
Authors: Merkel C. , Gatta A. , Arnaboldi L. , Zuin R. 
Published: April 2008

Summary. The relationships between portal hypertension and spleen enlargement, in patients with liver cirrhosis, are not clearly defined; as well as those between splenic haemodynamics and portal hypertension.In 25 cirrhotics with spleen enlargement and portal hypertension and in seven controls, the following parameters were determined: estimated splenic volume (ESV) from the radiographic view of the spleen, according to Blendis, Williams and Kreel (1969), specific splenic blood‐flow (SSBF), total splenic blood‐flow (TSBF), porto‐hepatic gradient (PHG), specific splenic resistance (SSR) and total splenic resistance (TSR). Moreover, the size and extension of oesophageal varices, at oesophagoscopy, were classified according to Dagradi (1973). PHG, ESV and TSBF were increased in all subjects, SSBF was increased in two cases, SSR was increased in two cases and decreased in two cases, TSR was decreased in all cases and ESV was not correlated to the level of portal hypertension. Neither TSBF nor TSR were found to be correlated to the level of portal hypertension, as estimated by PHG or by oesophageal varices.It is concluded that, in patients with liver cirrhosis and spleen enlargement, splenomegaly is likely to be the consequence of pulp hyperplasia and not of passive congestion, and that increases in splenic blood‐flow do not contribute significantly to portal hypertension.
Effects of a thromboxane antagonist (BM 13·177) during endotoxin‐induced pulmonary vasoconstriction in sheep
Authors: HüUttemeier P. , Eliasen K. , Mogensen T. , Bell M. , SøSrensen J. NøSrtved , Ovist J. 
Published: April 2008

Summary. We investigated the effect of a thromboxane antagonist, BM 13·177, during endotoxin‐induced pulmonary vasoconstriction in sheep. In control animals intravenous E‐coli endotoxin (1 μg/kg) caused a transient increase of pulmonary artery and airway pressure paralleled by large concentration increases of TXB2: in comparison peak plasma concentrations of 6‐keto‐PGFlα (a prostacyclin metabolite) were small and delayed in time. Pre‐treatment with BM 13·177 (bolus 5 mg/kg), followed by 0·75 mg/kg/min intravenously) abolished the rise of pulmonary artery and airway pressure. Plasma concentrations of TXB2 and 6‐keto‐PFGla were similar to controls.These and previous investigations imply that BM 13·177 specifically antagonizes TXA2 on the putative receptor in pulmonary vascular and airway smooth muscle.
Muscle adaptations and glucose control after physical training in insulin‐dependent diabetes mellitus
Authors: Mandroukas K. , Krotkiewski M. , Holm G. , Strömblad G. , Grimby G. , Lithell H. , Wroblewski Z. , Björntrop P. 
Published: April 2008

Summary. Six men and three women with insulin‐dependent diabetes (without complications) participated in physical training three times a week for 20 weeks. Physical training did not change the concentration of fasting blood‐glucose, glucose excretion in urine or glucosylated haemoglobin (HbA1). However, the glucose disposal rate during euglycaemic clamp increased after training. In two patients a minor reduction of insulin dosage was necessary to alleviate slight hypoglycaemic episodes. The training resulted in significant increases in quadriceps isometric and dynamic strength and endurance. Maximal oxygen uptake increased by 8%, the activity of glycolytic enzymes in vastus lateralis muscle by 47% for hexokinase, and 30% for tri‐osephosphate dehydrogenase and 25% for lactic dehydrogenase, the activity of oxidative enzymes by 42% for citrate synthase and 46% for 3‐hydroxy‐acyl‐CoA‐dehydrogenase. The glycogen concentration in the vastus lateralis muscle did not change significantly. Lipoprotein lipase activity did not change in muscle, nor in adipose tissue. The mean muscle fibre area increased by 25% and the area of FTa fibres by 30%. The new formation of capillaries around different muscle fibres was significant for FTb fibres (26%). The proliferation of capillaries, however, appeared to be insufficient to cope with the increased area of muscle fibres. As a result, the mean area of muscle fibre supplied by one capillary (a measure of diffusion distance) significantly increased after training for FTa fibres.It is concluded that with the exception of deficient proliferation of capillaries, patients with insulin‐dependent diabetes mellitus show a normal central and peripheral adaptation to physical training. Physical training does not apparently improve blood glucose control in most cases, despite an increased insulin sensitivity.
Increased sympathetic tone in forearm subcutaneous tissue in primary hypothyroidism
Authors: Nielsen H. Vagn , Hasselström K. , Feldt‐Rasmussen U. , Mehlsen J. , Siersbæk‐Nielsen K. , Friis Th. , Haunsø S. , Trap‐Jensen J. 
Published: April 2008

Summary. Sympathetic reflex regulation of subcutaneous blood flow (SBF) in the forearm was studied in eight patients with primary hypothyroidism. Diastolic arterial pressure was ≥95 mmHg in five patients. SBF was determined by local clearance of Na99mTcO4.Sympathetic vasoconstriction normally seen after lowering the forearm 40 cm below heart level was absent since SBF only decreased by 4% (± 7%, P > 0·1) during these conditions. In head‐up vertical position we noticed a diminished baroreceptor response as SBF at heart level was reduced by 11% (±7%, P < 0·1) compared to supine position. After proximal local anaesthesia SBF increased by 351% (±81%, P < 0·01) and disclosed a normal vasoconstrictor response as SBF was reduced by 53% (±5%, P < 0·01) during arm lowering.Five of the treated patients were restudied in the euthyroid state. Mean arterial pressure was reduced in mean by 20 mmHg (± 6 mmHg, P < 0·02) during treatment and a significant vasoconstriction was observed both during arm lowering (SBF =‐52% (±6%, P<0·02)) and in head‐up vertical position (SBF= ‐45% (± 11%, P<0·02)).In conclusion sympathetic vasoconstrictor activity in adipose tissue is markedly increased in primary hypothyroidism. Sympathetic tone and arterial pressure are reduced during treatment.
Haemodynamic response to exercise in patients with alcoholic liver cirrhosis
Authors: Kelbæk H. , Rabøl A. , Brynjolf I. , Eriksen J. , Bonnevie O. , Godtfredsen J. , Munck O. , Lund J. O. 
Published: April 2008

Summary. Physical work capacity was evaluated by a multistage bicycle exercise test in 29 patients, 22 men and seven women aged 35–61 years (mean 49) with alcoholic liver cirrhosis and in a sex‐ and age‐matched control group. The maximal work load was reduced in the patient group, mean 122 vs. 186 watts in men (P < 0·001), and 60 vs. 119 watts in women (P < 0·005). Resting heart rate was higher in patients (91 vs. 78 beats × min1, (P < 0·005), and the maximal heart rate was lower (159 vs. 170 beats × min‐1, (P < 0·001) compared with controls. Thirteen of 29 (45%) patients compared with 5 of 29 (17%) control subjects had an increase in left ventricular ejection fraction of ≤5% during exercise (P < 0·05).The present results suggest that an impaired capacity of the cardiac function to respond adequately to physical stress may at times contribute to the reduced physical work capacity seen in patients with alcoholic liver cirrhosis.
Human tibialis anterior contractile responses following fatiguing exercise with and without β‐adrenoceptor blockade
Authors: Alway S. E. , Hughson R. L. , Green H. J. , Patla A. E. 
Published: April 2008

SummaryThe effects of oral propranolol (2 × 80 mg/day) on the contractile responses to twitch and tetanic electrical stimulation were examined in the tibialis anterior (TA) muscle of seven healthy young males. The TA muscle was fatigued by four forms of repeated isometric contractions: (1) maximal voluntary contractions (MVC), (2) MVC with circulation occluded, (3) electrically evoked contractions with 20 Hz supramaximal voltage stimulation and (4) electrically evoked contractions with circulation occluded. Each contraction was sustained for 10 s with 5 s recovery. Duration of exercise was 10 min for intact circulation and 4 min for circulatory occlusion. Pre‐exercise, both the twitch contraction time and the 1/2 relaxation time were significantly (P<0·05) longer with β‐blockade than placebo, β‐blockade did not affect torque output during tetanic stimulation or MVC. Immediately post‐exercise, the peak twitch torque was reduced in all β‐blocked and placebo conditions except electrically induced exercise with intact circulation. The 1/2 relaxation time was significantly lengthened by repeated MVC with circulation intact; β‐blockade caused a greater lengthening than placebo (P<0·05). The tetanic torque was reduced immediately post‐exercise at each of 10, 20, 50 and 100 Hz for both β‐blockade and placebo for each form of exercise. There were no significant β‐blockade effects. Torque output at 10 Hz was still reduced up to 10 min post‐exercise. In contrast, 100 Hz torque output recovered by 5 min post‐exercise. The changes in tetanic responses were qualitatively similar with intact circulation and with circulatory occlusion. In the tibialis anterior muscle, the effects of fatiguing exercise are not accentuated by β‐blockade. These data in the TA are notably different from those in the triceps surae, where greater fatigue has been shown with β‐blockade.
Glomerular filtration rate estimated from a single plasma sample after contrast‐enhanced radiological examinations
Authors: Boijsen M. , Jacobsson L. , Tylén U. 
Published: April 2008

SummaryIn twenty‐six patients examined with radiographic procedures, including a single injection of meglumine metrizoate, blood samples were drawn 180,200,220 and 240 min after injection. Plasma was analysed for iodine concentration with X‐ray fluorescence analysis and the total plasma clearance of metrizoate was calculated with the single sample method from each sample.The results were compared with the total plasma clearance of 51Cr‐EDTA, calculated from multiple samples and determined no more than a few days apart from the X‐ray examination. A good correlation, ranging from 0·91 and 0·94, was found. We therefore conclude that kidney function can be estimated from a single plasma sample after contrast‐enhanced radiological examinations.
Whole body fat oxidation before and after carnitine supplementation in uremic patients on chronic haemodialysis
Authors: Lundholm K. , Persson H. , Wennberg A. 
Published: April 2008

Summary. This study has evaluated whether uremic patients on chronic haemodialysis with subnormal plasma levels of free carnitine show any alterations in whole body fat oxidation before and after one week with carnitine supplementation (60 mg/kg/day).Carnitine plasma levels changed from subnormal to supranormal levels of both free and total carnitine concentrations. This increase was not associated with any alteration in either oxygen uptake, carbon dioxide production, respiratory quotient or blood substrate levels such as glucose, glycerol, free fatty acids and lactate. The fractional oxidation of an intravenously infused fat emulsion (Intralipid®) was 17% before and 19% after carnitine supplementation. No side effects were observed in spite of the rather high dose of carnitine administration.This study failed to demonstrate any impact on net whole body fat oxidation in carnitine substituted uremic patients with initially subnormal levels of free plasma carnitine.
The Q‐oTc and Q‐Tc interval and ionized calcium in newborns
Authors: Nelson N. , Illés L. 
Published: April 2008

Summary. Ionized calcium (CaF), Q‐oTc and Q‐Tc intervals were determined in 31 full‐term healthy newborns, 12 infants subjected to blood exchange transfusion (ET) and 10 infants with verified clinical hypocalcaemia.There was no significant correlation between CaF values and QT intervals. The large fluctuations in CaF during ET did not correspond to any similar change in Q‐oTc or Q‐Tc intervals.The Q‐oTc interval was slightly longer in the hypocalcaemic and the blood exchanged groups compared to controls. The Q‐Tc interval was somewhat longer in the ET group.The differences in mean values for QT intervals were fairly small and the ranges wide.ECG findings lack practical implications in diagnosing and following neonatal hypocalcaemia and we therefore recommend the measurement of CaF as a guideline.
On the consistency of ECG reports from two different computer‐based ECG recorders
Authors: Jakobsson A. , Pahlm O. , Reichert L. , Edenbrandt L. , Nilsson B. 
Published: April 2008

Summary. Four consecutive computer‐based ECG recordings/interpretations were made on each of 100 patients. Two of the recordings were made with the MAC II recorder (Marquette Electronics Inc., Milwaukee, USA) and two with the Cardisuny IC503FA (Fukuda M‐E Kogyo Co. Ltd, Tokyo, Japan). Computer measurements of PQ interval, Q‐width in III, R‐amplitude in V5 and QRS axis in the frontal plane were compared between recordings, as also were diagnostic statements pertaining to the presence of atrial fibrillation and myocardial infarction.The MAC II was found to be more consistent than the Cardisuny as regards the measurements. There was a tendency that the MAC II was more specific than the Cardisuny and the Cardisuny more sensitive than the MAC II. The MAC II gave no false positive reports of atrial fibrillation and only one false positive report of myocardial infarction.
Influence of local β‐adrenoceptor blockade on exchange of fat and glucose in the human leg after surgery
Authors: Håkanson E. , Rutberg H. , Jorfeldt L. 
Published: April 2008

Summary. The metabolic effects of the local administration of propranolol were determined in seven patients undergoing cholecystectomy. Measurements were carried out in the early postoperative period before and after infusion of 2 mg of intraarterial propranolol into the femoral artery of one leg using the other leg as control. Blood flow and arterio‐venous concentration differences for oxygen, glucose, lactate, alanine, glycerol and total FFAs were determined. Uptake and release of FFAs were determined by using a tracer technique. The statistical analyses were based on differences between the test and the control leg in changes following the blockade.Glycerol release was significantly more suppressed in the test leg than in the control leg. No difference between the legs was seen in the uptake of oxygen, FFA and glucose or the release of lactate and alanine. The arterial concentration of propranolol was 6·07 ± 0·72 ng ml‐1 (mean ± SEM).This study indicates that a local β‐blockade by intra‐arterial propranolol infusion after surgery slightly reduces the postoperative lipolysis in leg tissues but does not influence or only marginally influences leg blood flow and oxygen uptake or the exchange of glucose, lactate and alanine after moderate surgical trauma.
The forearm and leg perfusion techniques in man do not give the same metabolic information
Authors: Möller‐Loswick A.‐C. , Bennegård K. , Lundholm K. 
Published: April 2008

Summary. The present study evaluates whether forearm and leg perfusion techniques give the same metabolic information. Seven patients hospitalized for operation of uncomplicated disease were investigated pre‐operatively in the fasted state, while seven other patients who were on intravenous nutrition were studied in the fed state. Blood flow and the extremity exchange of glucose, lactate, glycerol, free fatty acids and amino acids were measured simultaneously across the forearm and the leg in all individuals.In the fasted state the arteriovenous difference (a‐v) of glucose uptake was statistically significant across the forearm while it was statistically insignificant across the. leg (0·27 ± 0·06 vs. ‐0·04±0·13 mmol l1). The a‐v differences of glycerol (0·025 ± 0·028 vs. ‐0·043 ± 0·013 mmol l1) and free fatty acids (0·10 ± 0·03 vs. ‐0·10 ± 0·04 mmol l1) were positive across the forearm while they were negative across the leg (P < 0·01). In the fasted state the a‐v difference of oxygen uptake (3·93 ± 0·67 vs. 3·21 ± 0·44 mmol l1) and blood flow (4·1 ± 1·0 vs. 4·0 ± 0·7 ml min1 100 g1) did not differ between the arm and the leg, but the a‐v difference in carbon dioxide production was significantly higher (P<0.05) across the forearm (2·43 ± 0·37 vs. 1·29 ± 0·29 mmol l1) compared to the leg. In the fed state all the above‐mentioned differences between forearm and leg became statistically insignificant. In the fed state the a‐v difference of the sum of all amino acids was not significantly different from zero balance across the forearm (‐146 ± 103 mmol l1) while there was a significant release from the leg (‐175 ± 6 mmol l1, P<0.05). In the fed state the flux of the sum of all amino acids became significantly positive across the arm while it was not significantly different from zero balance across the leg. In the fed state, forearm blood flow was significantly higher than leg blood flow (6·2 ± 0·5 vs. 4·0 ± 0·2 ml min1 100 g1, P<0.001).The results in the present study demonstrate that the metabolic balance across regions of peripheral tissues may simultaneously differ considerably, i.e. being positive across the forearm and negative across the leg. This fact may imply that some previous claims may need reconsideration about ‘peripheral tissue metabolism’ associated with a certain clinical condition.
The effect of increasing temperature on skin blood flow and red cell deformability
Authors: Rendell M. S. , Kelly S. T. , Bamisedun O. , Luu T. , Finney D. A. , Knox S. 
Published: April 2008

Summary. Using laser Doppler techniques in nine healthy volunteers, we contrasted the effect of increasing local skin temperature at the elbow, a skin site with nutritive microvasculature, and the finger pulp, with predominantly arteriovenous anastomic (AVA) perfusion). We also assessed flow at the finger dorsum, with contributions of both types of microvasculature. In parallel with the laser Doppler studies, we determined the effect of increasing temperature on the red cell deformability of our subjects, using the new technique of Cell Transit Time Analysis (CTTA). Thermal stimulation produced very large increases in skin blood flow at all three sites tested. However, the magnitude and the pattern of increase were different at the three sites. At the finger pulp, there was a linear approximately threefold increase in flow as temperature increased from the basal level to 44°C. At the elbow, basal flow was considerably lower than at the finger pulp and increased very slowly until skin temperature reached 38°C. From that point, flow increased sharply, reaching tenfold the basal level at 44°C. The thermally induced increase at the finger dorsum was intermediate between the other two sites, with a pattern resembling the elbow more than the finger pulp. These differences among the sites were attributable to substantially different patterns of change in the two components of flow, microvasvular volume and velocity. At the finger pulp, there was very little increase in microvascular volume with increasing temperature. The curve was practically flat from basal temperature to 44°C. In contrast, there was a linear increase in red blood cell velocity of about 300%. At the elbow, both microvascular volume and red blood cell velocity exhibited a parallel curvilinear pattern of equivalent increase, on the order of 300% for each. There was only a small increase in both parameters until the temperature reached 38°, at which point there was a sharp increase in both. At the finger dorsum, the situation was intermediate, again resembling the elbow more than the finger pulp.Cell Transit Time Analysis revealed a progressive decrease in red cell transit time (TT), from 3.28 ms at 28°C to 2.48 m at 44°C, an overall change of 24%. The decrease in TT was accompanied by an increase in transit frequency, measured as counts s‐1 (C s‐1), from 3.1 to 5.3, an overall change of 71%. The changes in both TT and C/S were essentially linear.Our present findings demonstrate that cutaneous AVA beds differ significantly from nutritive capillary beds in the mechanisms of thermally induced flow change. The 24% observed increase in red cell transit time on CTTA would suggest only a small potential rheological contribution to increased red blood cell velocity. However, the increase in counts s‐1 of about 70% suggests that improved red cell entry into capillaries is a factor in the thermally induced increase in microvascular volume.