bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of muscle mitochondrial function with techniques applicable to needle biopsy samples
Authors: Gohil K. , Edwards R. H. T. , Jones D. A.
Published: April 2008

Summary. Methods are described for the assessment of mitochondrial function in small (less than 50 mg) samples of human skeletal muscle using spectrophotometric assays to follow the reduction or oxidation of added cytochrome c.

Activities of pyruvate plus malate cytochrome c reductase [(P + M)CR], α‐oxo‐glutarate cytochrome c reductase (OgCR) glutamate cytochrome c reductase (GCR), succinate cytochrome c reductase (SCR) and cytochrome c oxidase (COx) were measured in various rat tissues and samples of human skeletal muscle. In all tissues the activities were in the order (P + M) CR<SCR<COx, although there were wide variations in the absolute levels of activity.

Rates of (P + M)CR and SCR activity measured spectrophotometrically in hypotonic medium were similar to the equivalent rates of oxygen uptake measured in isotonic medium with an oxygen electrode.

Because the spectrophotometric assays have to be carried out in hypotonic medium, mitochondria are uncoupled and the method cannot be used to examine this aspect of mitochondrial function.

Measurements can be reliably made on a single needle biopsy specimen of human muscle and by measuring a number of different activities the function of the whole electron transport chain and a number of tricarboxylic acid cycle enzymes can be determined. The clinical use of the methods is illustrated with results from selected patients with specific defects of mitochondrial metabolism.

The methods offer a convenient way both for screening and the detailed and repeated study of patients.
Circulatory response to static muscle contractions in three different muscle groups
Authors: Kilbom Åsa , Persson Jan
Published: April 2008

Summary. The circulatory responses to static contractions of three different muscle groups were compared. Contractions at 15 and 25–30 % MVC of forearm muscles (hand‐grips) were compared to quadriceps muscle contractions in eleven male subjects, and in 10 subjects the response to hand‐grip contractions and foot plantar flexion was studied.

All contractions at 15% MVC induced slight but significant changes in heart rate (HR); intra‐arterial blood pressure (BP) changes were more marked. 25–30 % MVC intensities always elicited a greater HR ‐and BP response than 15 % intensity in the same muscle group.

Stroke volume (measured during hand‐grips and quadriceps contractions) was unchanged at all exercise intensities; hence, HR was a reliable measure of changes in cardiac output (Q). The circulation became hyperkinetic during exercise, since the rise in oxygen uptake was very slight despite a moderate increase in Q.

Quadriceps contractions always elicited a larger HR, BP and Q response at a given time than hand‐grip contractions and the HR and BP at foot plantar flexion was always least marked. HR at exhaustion followed the same pattern. It is suggested that differences in functional properties of muscles are partly responsible for the magnitude of the reflex cardiovascular response during static contractions, but muscle strength and size may also influence the results.
Interstitial fluid: Exchange of macromolecules between plasma and skin interstitium
Authors: Rossing Niels , Worm Anne‐Marie
Published: April 2008

Summary..Fluid was collected from blisters developed by suction on the abdominal skin in ten normal volunteers. During the same study the transcapillary escape rate of intravenously injected131I‐albumin and125I‐IgG together with the accumulation of these tracers in the blister fluid was measured.

The ratios between the concentrations of endogenous albumin, transferrin, IgG and a2‐macroglobulin in the blister fluid (Cb) and serum (Cs) correlated directly with the free diffusion coefficients indicating that the sieving properties of the vascular endothelium remained intact during the suction.

The ratios of intravascular to total masses of the four endogenous proteins calculated from plasma volume, Cs, Cb and extracellular fluid volume determined with inulin and Cb were very similar to those obtained in long‐term metabolic turnover studies.

The ratio between the accumulated IgG and albumin tracers in the blister fluid (0–80) was identical with the Cb/Csratio between endogenous IgG and albumin (0–78) but higher than the ratio between the IgG and albumin escape rates from the total micro‐vasculature (0–58). From the protein tracer determinations it cannot be definitely excluded that suction increases the microvascular escape rates.

If the distribution volume of inulin equates that of albumin in steady‐state it can, however, be concluded from the data given on the endogenous plasma proteins, that blister fluid from the abdominal skin corresponds to average interstitial tissue fluid.
Effect of bicycle exercise on insulin absorption and subcutaneous blood flow in the normal subject
Authors: Ferrannini Eleuterio , Linde Birgitta , Faber Ole
Published: April 2008

Summary. Elimination of 8 units 125I‐insulin and 99mTc‐pertechnetate from a subcutaneous depot on the thigh or the abdomen was studied at rest and during intense bicycle exercise in healthy postabsorptive volunteers. Disappearance rates of the tracers as well as plasma insulin and glucose concentrations were determined before, during and after the 20 min exercise period, and compared to corresponding values obtained during a non‐exercise, control study on another day.

Leg exercise caused a two‐fold increase in the rate of 125I‐insulin disappearance from a leg depot (first‐order rate constants rose from 0·68 ± 0·15 to 1·12 ± 0·12%·min‐1, P <0·05), but had no significant effect on the rate of disappearance from an abdominal depot (rate constants were 0·75 ±0·17 and 0·87±0·18%·min‐1 at rest and during exercise, respectively). 99mTc‐pertechnetate clearance from leg or abdomen showed no significant change during exercise, indicating that subcutaneous blood flow was unaltered.

Leg, but not abdominal, injection of insulin was associated with a greater rise in plasma insulin during exercise than at rest. The average difference between exercise and control insulin area‐under‐curve in the leg group (1426 ± 594%·min) was significantly greater (P <0·05) than that from the abdominal group (298 ±251%· min). When the data from the two study groups were pooled, a direct relationship was found to exist between the change in 125I‐insulin disappearance rate and the change in plasma insulin concentration (r=0·61, P <0·02).

Plasma glucose levels fell throughout the observation period both during the exercise and the control study, following leg as well as abdominal injection. The glucose decremental area was greater during exercise than at rest both following leg (P <0·05) and abdominal injection (P <0·01). The exercise‐induced mean reduction in plasma glucose was 60% lower following abdominal injection, but this difference was not significant.
Perfusion of the intervillous space of the human placenta measured with 99mtechnetium labelled human serum albumin
Authors: Andersen K. Vitting , Andersen S. Vitting , Munck O. , Larsen J. Falck , Nielsen S. Levin , Kjeldsen H.
Published: April 2008

Summary. The perfusion of the intervillous space of the human placenta was investigated with 99mTc‐Human Serum Albumin and external counting in 45 pregnant women between the 34th and 38th week of gestation. The pregnancy was normal in 34 women, while there was placental insufficiency in 11. Two variables were calculated from the placenta curve: the placenta flow index (PFZ) and the mean transit time (t) for plasma through the intervillous space. From double determinations, the coefficient of variation for PFI was calculated to 1·6%. For t it was 20%.

PFZ was significantly higher in the controls than in the patients with placental dysfunction (P < 0·05). There was a significant correlation between PFZ and i (rs= ‐0·36, P<0·05). The plasma oestriol level and the PFZ correlated significantly, whereas the correlation between i and the plasma oestriol level was not significant.

The placenta flow index can be used to measure the physiological effect of a pharmacological treatment, bedrest or other treatments.
Body mass index and physical fitness as determinants of serum lipoprotein levels in middle‐aged men
Authors: Kukkonen Katriina , Rauramaa Rainer , Voutilainen Erkki , Hietanen Eino
Published: April 2008

Summary. The aim of the present study was to analyse to what extent serum lipoproteins are determined by overweight and physical fitness. Fifty‐eight middle‐aged males were divided into lean, overweight and obese subgroups according to their body mass indices, which characterization was also well in accordance with two skinfold thicknesses. Maximal oxygen consumption per body weight was lowest in the obese. HDL cholesterol was decreased in the obese compared to the lean. HDL cholesterol correlated separately significantly with maximal oxygen consumption and body mass index when all the three groups were combined. Physical fitness was a less dominant determinant of HDL cholesterol than body mass index. The importance of physical fitness as a determinant of HDL cholesterol was less marked in the obese than in the lean and overweight suggesting a need for certain level of physical activity before it can influence serum lipoprotein levels.
Influence of second‐order data filtering on common forced expiration indices
Authors: Peslin R. , Jardin P.
Published: April 2008

Summary. Forced expiratory manoeuvres are extensively recorded using flow meters coupled to pressure transducers, which usually behave like second‐order filters. To assess what should be the dynamic characteristics of such equipment for accurate determination of common forced expiration indices, 125 curves were obtained from 25 healthy subjects in the best technical conditions. The flow‐time curves were then submitted to various degrees of second‐order filtering, and the indices derived from filtered and unfiltered curves were compared. Considering that experimental error is acceptable if it does not exceed 20% of the normal interindividual variability for 95% of the curves, the following conclusion was drawn; with an optimal damping ratio (r) of 0.7, forced expiratory volume in one second, maximum midexpiratory flow rate and maximal expiratory flow at 25 % of the forced vital capacity (MEF25) are still correctly measured when the resonant frequency (fn) is as low as 3 Hz. The corresponding figures are 5 Hz for MEF50 20 Hz for peak expiratory flow rate and above 20 Hz for MEF75. Higher values of fn are usually required when r is higher or lower than 0.7.
Splanchnic galactose uptake in patients with cirrhosis during continuous infusion
Authors: Lindskov J. , Ranek L. , Tygstrup N. , Winkler K.
Published: April 2008

Summary. The galactose elimination capacity (GEC) is considered a test of functional liver cell mass. The main uncertainties of the method are the effects of extrahepatic elimination and of uneven distribution in the body on the calculated maximal elimination rate of galactose. This has been evaluated by hepatic and renal venous catheteriza‐tion during continuous infusion of galactose at two arterial concentration levels (mean 6·0 and 8·7 mmol l1) in 10 patients with reduced liver function. Hepatic and renal blood flow were measured by constant infusions of Indocyanine Green and 131I Hippuran.

Hepatic galactose elimination rate was identical (mean 1.36 and 1·32 mmol min1, P > 0·4) at the two arterial concentration levels studied, indicating that hepatic galactose elimination rate was maximal (Vmax). The total body galactose elimination rate, calculated as amount infused during steady state, was 1·4 times greater than the hepatic elimination rate, calculated as arterio‐hepatic venous concentration difference times hepatic blood flow. Within the experimental error, the extrahepatic (i.e. total minus hepatic) galactose elimination could be accounted for by renal elimination.

The steady state studies show that the galactose elimination capacity, estimated from single injection, overestimates the hepatic Vmax by about 25%. The reason for this is probably mainly distribution phenomena and insufficient correction for urinary loss, but extrahepatic metabolism of galactose cannot be excluded.
Calcium metabolism evaluated by 47calcium‐kinetics: a physiological model with correction for faecal lag time and estimation of dermal calcium loss
Authors: Jensen F. Taagehøj , Charles P. , Mosekilde L. , Hansen H. Hvid
Published: April 2008

Summary. Sixty‐two calcium balance and 47Ca‐turnover studies were performed in 51 individuals to evaluate the accuracy and the sensitivity of the methods. The data were analysed according to a modification of the expanding calcium pool model using an improved Bauer‐Carlsson‐Lindquist (BCL) formulation and an iterative computer procedure. A 7‐day whole body retention curve (R1) combined with a retention curve constructed from excretion data alone (R2) was used to estimate dermal calcium loss (d) and to demonstrate the significance of individual corrections for delay in faecal excretion (faecal lag time =δt). The mean d was 1–58 mmol Ca/day. The introduction of δt improved the goodness of fit of the data to the model. δt based on 47Ca‐kinetics was superior to a fixed δt of zero (P < 0·01) or 2 days (P < 0·05). The model derived renal calcium excretion rate was highly correlated (r= 0·98, P < 0·001) to the chemical measured excretion rate. A similar highly significant correlation [Rs= 0·78 (Spearman), P < 0·001] was found between the model derived δt and the carmine red δt. These results indicate a high accuracy of the model. The directly measured parameters showed an excellent reproducibility with a coefficient of variation (CV) less than 4%. The reproducibility of the derived parameters was acceptable (CV = 10–20%) except for the balance (CV = 72%).
Non‐invasive determination of effective stroke volume. Evaluation of a CO2‐rebreathing method in normal subjects and patients
Authors: Ohlsson Jan , Hlastala Michael P. , Tranesjö Jussi , Wranne Bengt
Published: April 2008

Summary.A CO2‐rebreathing method for the determination of stroke volume(SV)was evaluated at rest by comparison with the direct Fick technique in 50 randomly selected patients with valvular heart disease. Patients with intracardiac shunts were excluded. Objective criteria for acceptance of a measurement were set to ensure reliable results. Forty‐six of the 50 patients fulfilled these criteria. The rebreathing manoeuvre is, in itself, an effort for the patient, leading to a change in steady state which excludes simultaneous comparison with the direct Fick method. Day‐to‐day variation of theSVmeasured with the CO2‐method was therefore assessed first, and found to be low. Because of this low day‐to‐day variation, a comparison of stroke volumes measured one day with the CO2‐method and next day with the direct Fick technique was found to be acceptable. In the determination ofSVin the supine position, there was no significant difference between the two methods (SVCO2= 5·2 + 0·90 ×SVFick,r= 0·90, SDres= 9·4 ml,n= 46), while cardiac output was significantly higher when measured with the CO2technique than with the direct Fick method (22%, P < 0·001). Ten of 12 patients with signs of obstructive lung disease managed to produce registrations which fulfilled the criteria of acceptance. The method is well suited for clinical use.
Inulin single injection clearance. Microsample technique useful in children for determination of glomerular filtration rate
Authors: Müller‐Suur R. , Göransson M. , Olsen L. , Bâcklund G. , Bäcklund L.
Published: April 2008

Summary. The agreement between single injection inulin (polyfructosan) clearance and two reference methods for glomerular filtration rate (GFR) determination, namely standard inulin constant infusion clearance and 51‐Cr‐EDTA single injection clearance, was investigated. Studies were also made to see whether different results were obtained when capillary and venous blood samples were used in the single injection clearance method. The investigation was made in children from one year of age, adult patients and volunteers. For the single injection technique with inulin or 51‐Cr‐EDTA, five to seven blood samples were taken in a period of up to 180 min after injection. A bi‐exponential plasma disappearance curve was used for calculations of single injection clearances. Good agreement was obtained between venous inulin single injection clearance on the one hand, and standard inulin clearance (correlation coefficient r= 0·86) and 51‐Cr‐EDTA single injection clearance on the other (r = 0·85). With use of capillary blood samples in inulin single injection clearance, similar good agreement was obtained both with venous 51‐Cr‐EDTA and with venous inulin single injection clearance (r = 0·85 and r= 0·89 respectively). From these results we conclude that inulin single injection clearance is a reliable method for GFR determinations. This method is recommended, especially in children, as capillary blood samples can be used.
Quantitative estimation of anaerobic and oxidative energy metabolism and contraction characteristics in intact human skeletal muscle in response to electrical stimulation
Authors: Sjöholm Hans , Sahlin Kent , Edström Lars , Hultman Eric
Published: April 2008

Summary. A set up for electrical stimulation of the human quadriceps femoris muscle and registration of tension is described. Normal values for the frequency‐tension relations and relaxation time are presented. There was no relationship between contraction characteristics and fibre type distribution. Muscle tissue was sampled after electrical stimulation by percutaneous biopsy technique. Phosphocreatine (PCr) decreased during a 75 s isometric contraction from 76 mmol per kg dry muscle down to a mean value of 9 mmol. Lactate increased during the same time period from 5 mmol per kg dry muscle to 100 mmol. At end of contraction there was a rapid resynthesis of PCr with a half time of about 20 s while the lactate content decreased slowly. The relaxation time of the muscle was prolonged from 38 ms, in non‐fatigued muscle, to 128 ms after 75 s of isometric contraction. The relaxation time was normalized after the contraction at the same rate as the resynthesis of PCr. It is proposed that the relationship between PCr and lactate of contracting muscle can be used as an index of glycolytic capacity and that the rate of resynthesis of PCr after contraction is a measure of oxidative capacity. Relaxation time measurements alone may be used as a non‐invasive estimation of the oxidative capacity.
Simultaneous assessment of right ventricular ejection fraction and central haemodynamics at rest and during exercise in patients with pulmonary hypertension
Authors: Dahlström J. A.
Published: April 2008

Summary. In 10 patients, aged 55–73, with pulmonary hypertension, right ventricular ejection fraction (RVEF) was measured simultaneously with central haemodynamics twice, at rest and during exercise. In the first investigation, RVEF was measured with first pass (FQ) radionuclide angiocardiography using 133Xe and 99Tcm as tracers. In the second investigation after 1 h's rest, RVEF was measured with equilibrium (EQ) radionuclide angiocardiography. Significant correlations were found between RVEF and pulmonary artery pressure (r = ‐ 0. 76 to ‐ 0. 88) and between RVEF and right arterial pressure (r= ‐0. 76 to ‐0. 84) at rest and during exercise. RVEF was low or decreased during exercise in all patients with haemodynamic signs of right ventricular failure. Good correlations were found between the FP and EQ techniques for measuring RVEF both at rest, r= 0.86, and during exercise, r= 0.91. RVEF, measured with the FP technique, showed better reproducibility and better correlation to haemodynamic variables and to history of right ventricular failure than the EQ technique. Thus, the FP technique seemed to be the method of choice for assessment of RVEF.
Flow‐volume relations in coronary circulation and distribution of coronary flow into nutritional and non‐nutritional compartments
Authors: Virtanen Kari S. , Järvinen Antero , Alitalo Ilkka , Riihimäki Esko
Published: April 2008

Summary. Simultaneous assessment of coronary flow and flow‐volume relation makes it possible to evaluate the dilatatory responses of coronary vasculature. Anew set up of methods for investigation of the coronary circulation was employed to study the nature of the coronary flow and volume responses to dipyridamole in dogs.

The turnover rate of coronary blood, the reciprocal value of the mean transit time, can be accurately determined by computer simulation analysis of coronary dye dilution curves. After intravenous dipyridamole (0·5 mg/kg) both coronary turnover rate and electromagnetically assessed blood flow were observed to increase in parallel and to the same degree (+55%). This indicates that no increase in the coronary vascular volume and, accordingly, no significant overall coronary dilatation takes place. The effective coronary blood flow in relation to the myocardial oxygen consumption, i.e. the nutritional flow, and the myocardial oxygen consumption decreased by 25% concomitant to a corresponding fall in myocardial oxygen requirements. Thus, the increase in total coronary flow after dipyridamole is useless for myocardial metabolism, and may properly be denoted as luxury perfusion or throughput flow.
Passage of albumin from plasma to suction skin blisters
Authors: Staberg Bent , Groth Steffen , Rossing Niels
Published: April 2008

Summary.To study the transvascular passage of albumin from the plasma to the skin interstitium, suction blisters were developed on the abdominal skin of six young, healthy male volunteers. Fifteen minutes after the blisters had been formed and the suction had been stopped,125I‐albumin was injected intravenously and the disappearance of the tracer protein from plasma was compared to its appearance in blister fluid as a function of time for up to 4 h after the injection. There was a linear increase of blister fluid activity with time after injection and the mean accumulation rate of the six subjects was 0·9 ± 0·4 (SD)%/h. It is suggested that this figure is a representative measure of the leakage of albumin through the skin microvasculature. In previous studies, a ten‐fold higher accumulation rate of albumin was found when the protein tracer was administered intravenously before the suction was induced. This difference was probably due to a suction‐induced increase of the filtration gradient across the skin vessels. It is concluded that both methods might be used to obtain a comparative measure of the local rate at which albumin passes from plasma to the interstitial fluid of the skin.
Hypoxia elicits liberation of anti‐aggregatory substances from isolated rabbit hearts
Authors: Edlund Anders , Wennmalm Åke
Published: April 2008

Summary. The hypothesis was investigated that myocardial hypoxia stimulates the production of platelet anti‐aggregatory substances in the heart. Rabbit hearts were perfused under normoxic or hypoxic conditions and the coronary and interstitial effluents from the hearts were separated. The occurrence of anti‐aggregatory activity (AAA) in the interstitial effluent was detected in vitro from its capacity to inhibit ADP‐induced platelet aggregation. The AAA in the effluent was deemed to be prostacyclin (PGI2) if its release was abolished by administration of indomethacin (5× 10‐5 M) to the heart, and to be adenosine if it was abolished by incubation of the effluent with adenosine deaminase.

During normoxic perfusion, only a minor efflux of AAA appeared from the heart; neither was the efflux appreciable during mild hypoxia (30 or 60% O2). Severe hypoxia (venous pO2 below 5 k Pa), on the other hand, was associated with a marked release of AAA. Incubation of hypoxic effluent with adenosine deaminase resulted in a small loss of activity, indicating that the major part of the AAA was not ascribable to adenosine. After indomethacin treatment, significant amounts of AAA still appeared in the effluent during hypoxia. However, unlike the case before indomethacin, this AAA was completely destroyed by adenosine deaminase.

From these data, we conclude that myocardial hypoxia can mobilize either of two independent mechanisms for protection against platelet aggregation: an activation of the synthesis and release of prostacyclin, and a more complete breakdown of ATP, leading to an increased formation and efflux of adenosine.
Effect of the Mueller manoeuvre at different lung volumes on left ventricular performance in normal subjects
Authors: Smucker Mark L. , Cassidy Sharon S. , Nixon J. V.
Published: April 2008

Summary. The effect of reduced intrathoracic pressure at different lung volumes on cardiac function was assessed by echocardiographic measurements of left ventricular size in normal subjects who performed the Mueller manoeuvre at two preselected lung volumes. At functional residual capacity (FRC), both mean end‐diastolic dimension and mean end‐systolic dimension increased (5·1±0·4 to 5·4±0·5 cm; P<0.001 and 3·7± 0·4 to 3·9± 0·4 cm; P<0·025, respectively). At high lung volume (HLV), midway between FRC and total lung volume, mean end‐diastolic dimension increased from 5·1±0·5 to 5·3±0·5 cm (P<0·001), less than the increase at FRC, and mean end‐systolic dimension increased from 3–520.4 to 3·9±0·4 cm (P<0–001), similar to the increase at FRC. Thus, mean stroke dimension and shortening fraction were reduced at HLV (1·5 ± 0·2 to 1·3 ± 0·2 cm and30 ± 4to26 ± 2% respectively, P < 0·025). At FRC and HLV respectively, mean left ventricular transmural pressure increased from 111 to 129 Torr (P<0·001) and from 111 to 128 Torr (P<0·001) in response to the Mueller manoeuvre, although intraesophageal (intrathoracic) pressure was significantly lower (P < 0·001) during the Mueller manoeuvre at HLV.

These results show that lung volume affects the left ventricular response to the Mueller manoeuvre. Furthermore, the changes in left ventricular dimensions induced by the Mueller manoeuvre are determined by the level of reduced intrathoracic pressure, through differing effects on left ventricular afterload and filling.
Plasma‐to‐ascitic fluid transport rate of albumin in patients with decompensated cirrhosis. Relation to intraperitoneal albumin
Authors: Henriksen Jens H. , Ring‐Larsen Helmer , Lassen Niels A. , Parving Hans‐Henrik , Winkler Kjeld
Published: April 2008

Summary. Albumin‐kinetics and haemodynamic studies were performed in 20 patients with decompensated liver cirrhosis in order to improve the knowledge on genesis and perpetuation of hepatic ascites, especially with respect to determinants of intraperitoneal protein.

A positive relationship was found between the plasma‐to‐peritoneal transport rate of albumin (index of ‘lymph‐imbalance’) and the mass of intraperitoneal albumin (rlog= 0·82, P< 0·001), indicating a significant role of ‘lymph‐imbalance’ to sequestration of protein in the peritoneal cavity. Ascitic fluid albumin concentration was on the average 0.22 of that of plasma and directly correlated to the plasma concentration (rlin= 0·68, P < 0·01). The hydrostatic pressure difference across the splanchnic microvasculature (assessed as wedged hepatic vein minus inferior vena caval pressure) was directly correlated to the effective (plasma minus ascitic fluid) oncotic pressure (rlin= 0·74, P< 0·001) but significantly higher than that (P<0·005), indicating a ‘non‐equilibrium’ in the splanchnic Starling forces.

The results point to a multivariate genesis and perpetuation of cirrhotic ascites as laid down in the ‘lymph‐imbalance’ theory of ascites formation, whereas a ‘fluid equilibrium’ theory seems to be too simple, especially with respect to explain protein sequestration in the peritoneal cavity.
Biochemical responses of the myocardium and red skeletal muscle to Salmonella typhimurium infection in the rat
Authors: Ilbäck Nils‐Gunnar , Friman Goran , Beisel William R.
Published: April 2008

Summary. Previous studies with bacterial infections have demonstrated a reduced exercise capacity and equally pronounced catabolic responses in red and white skeletal muscle. In the present study, red skeletal muscle and heart ventricular muscle were compared in a S. typhimurium model in rats. Two days before median lethality was achieved, the activities of one oxidative (cytochrome c oxidase), one glycolytic (glyceraldehyde‐3‐phosphate dehydrogenase) and one lysosomal (beta‐glucuronidase) enzyme were determined in the two tissues. The contents of protein, RNA and DNA were also determined. The oxidative and glycolytic capacity decreased 24–29% in red skeletal muscle but only 7–20% in the myocardium. However, the decrease in oxidative capacity in skeletal muscle and myocardium was statistically correlated. The protein synthetic capacity (RNA) also decreased and was correlated to the protein concentration in both tissues. This metabolic impairment of both skeletal and heart muscle probably contributes to the deterioration of the physical performance capacity previously observed to follow acute infectious diseases. This study emphasizes the importance of the choice of reference, such as ‘wet’ weight, DNA or the entire organ, when evaluating metabolic results in biologic tissues and that biochemical alterations in skeletal muscle biopsies in bacterial infections do not reflect alterations in myocardium reliably.
Placenta flow index in posterior wall placentas measured with 99mtechnetium‐labelled human serum albumin
Authors: Andersen K. Vitting , Munck O. , Larsen J. Falck , Kjeldsen H.
Published: April 2008

Summary. Measurement of the perfusion of posterior wall placentas with the isotope technique may pose a problem owing to attenuation of the gamma radiation. The present investigation compares the placenta flow index (PFI) in 34 pregnant women with anterior wall placenta and 13 with posterior wall placenta.

We found no difference in the shortest skin‐to‐placenta distance on ultrasound scanning and no difference in PFI between the anterior and the posterior wall placentas.
Regional myocardial tissue blood flow during β‐adrenergic blockade in cat hearts with acute ischaemia
Authors: Stangeland Lodve , Grong Ketil , Lekven Jon
Published: April 2008

Summary. Selective β1 or β2‐adrenergic blockade was achieved by practolol or IPS 339, respectively, in cats with acute ligation of a coronary artery. During blockade, heart rate was kept constant by atrial pacing and blood pressure reduction was prevented by aortic clamping. Regional myocardial blood flow was measured by the distribution of 15 μm labelled microspheres. Practolol slightly reduced epicardial blood flow in ischaemic myocardium, while blood flow in border and normally perfused myocardium remained unchanged. Following IPS 339, myocardial tissue flow increased in normally perfused myocardium, on average by 37% in the endocardium and 30% in the epicardium. No changes occurred in the other regions. The flow changes brought about by IPS 339 were unrelated to haemodynamic changes, and the coronary vascular resistance was reduced. These results are indicative of coronary vasodilation related to β2‐adrenergic receptor blockade and was confined to well‐oxygenated areas surrounding the acutely ischaemic zone.
Myoglobin release in patients with angina pectoris following short‐term ischaemia by pacing to angina
Authors: Sylvén Christer , Berglund Bo , Kaijser Lennart
Published: April 2008

Summary. Thirteen patients with severe stable angina pectoris were studied by coronary sinus catheterization. In all patients, severe chest pains were produced by atrial pacing. The chest pains had disappeared within 10 min after pacing. Simultaneous arterial (a) and coronary sinus (cs) blood samples were taken before, during and after pacing and analyzed for myoglobin and lactate. The a‐cs difference of myoglobin tended to become more negative after pacing, although the change was not significant. However, the change in negative direction post‐pacing of the a‐cs myoglobin difference was quantitatively correlated with the change in negative direction of the a‐cs lactate difference during pacing in the individual patients. This suggests that short‐term myocardial ischaemia without signs of established myocardial infarction may provoke myocardial myoglobin release.
Ventilatory effects of biceps vibration during leg exercise in healthy humans
Authors: Jammes Y. , Askanazi J. , Weissman C. , Milic‐Emili J.
Published: April 2008

Summary. The ventilatory effects of biceps tendon vibration were studied in healthy human subjects at rest and at two levels of light leg exercise. This was performed with intent to add the ventilatory effects of selective stimulation of muscle spindles to nervous and humoral respiratory inputs from contracting muscles. Tendon vibration performed in individuals at rest elicited a marked increase in respiratory frequency and in the ratio between inspiratory time and total breath duration with variable changes in tidal volume; this was in agreement with previous results (Jammes et al., 1981). When stimulation of biceps proprioceptors was performed during steady state exercise, the changes in ventilatory timing were attenuated, but variations in tidal volume often occurred. These results suggest that, when respiratory centers are being entrained by performance of work, further activation of muscle receptors exerts complex effects on the breathing pattern with a lack of facilitatory influences in ventilation and gas exchange.
Response of plasma arginine vasopressin levels to rapid changes in altitude
Authors: Porchet M. , Contat H. , Waeber B. , Nussberger J. , Brunner H. R.
Published: April 2008

Summary. Plasma arginine vasopressin levels were studied in 15 normal working men exposed at 4‐day intervals to a rapid increase or decrease in altitude of 2000 m.

Plasma arginine vasopressin levels were significantly lower (P<0·001) at the higher altitude though plasma osmolality did not change.

It is concluded that the important diuresis known to physiologically occur in response to high altitude may be related to a decrease in antidiuretic hormone release.
Endocrine and metabolic responses after standardized moderate surgical trauma: influence of age and sex
Authors: Håkanson Erik , Rutberg Hans , Jorfeldt Lennart , Wiklund Lars
Published: April 2008

Summary. The endocrine and metabolic responses to elective cholecystectomy and the influence of age and sex on this stress response were investigated in 21 patients, eight men and 13 women. The patients were divided into two groups, older (n=10) and younger (n=11) than 55 years respectively. Arterial plasma concentrations of catecholamines, cortisol and free fatty acids as well as serum insulin and arterial blood concentrations of glucose, lactate, glycerol, alanine and 3‐hydroxybutyrate were measured preoperatively and 2, 24, 48, 72 and 96 h after the start of surgery. Oxygen uptake and CO2 production were measured and respiratory quotient (RQ) was calculated. All hormones and metabolites except insulin and alanine were significantly elevated immediately after surgery. At 24 h plasma noradrenaline and blood glucose were still significantly increased. Serum insulin was increased at 24 and 48 h. Oxygen uptake and plasma cortisol were significantly elevated throughout the period studied and blood alanine was decreased from 2 to 72 h after surgery. The older group showed a significantly higher increase in noradrenaline and lactate, whereas women preoperatively as well as postoperatively had higher glycerol levels. At the end of the period studied women had higher FFA‐levels. We conclude that cholecystectomy evokes a significant endocrine and metabolic response and that some of the variables studied are still significantly altered up to 4 days postoperatively. The influence of age and sex on this stress response is of minor importance.
Measurement of oxygen consumption in preterm infants: assessment of a method using a mass spectrometer
Authors: Hammarlund K.
Published: April 2008

Summary. A flow‐through system for measurement of oxygen consumption (V̇o2), carbon dioxide (V̇co2,) and water (V̇H2O) production using a mass spectrometer for analysis of PO2, Pco2 and PH2O, was assessed with regard to the range expected for very small preterm infants. The technique was tested by burning ethanol, and close correlations were found between the measured and the theoretical V̇O2 (V̇CO2, and V̇H2O) values. Close correlation was also found between the measured and the theoretical Vo, when oxygen in the system was displaced by a gas mixture containing 10% O2 in nitrogen. The V̇O2 values found in a small number of infants compare well with values published in the literature. During all tests V̇O2 was also measured using a paramagnetic oxygen analyser. No significant difference in To, was found between the theoretical values and the values found with the two different methods or between the two methods, when the infants were studied.
Left ventricular diastolic relaxation and pressure‐diameter relations during ischaemic left ventricular failure in the dog
Authors: Myhre Eivind S. P. , Piene Hroar
Published: April 2008

Summary. The significance of severe ischaemic left ventricular (LV) failure on the LV isovolumic relaxation process and diastolic chamber stiffness has been investigated in nine open‐chest pentobarbital‐anaesthetized dogs. LV failure was induced by bolus injections of 50 μm microspheres into left coronary vascular bed until LV minor axis diameter had increased about 25% and end‐diastolic pressure about 20 mmHg. Such ischaemic LV failure did not shift the relation between diastolic LV pressure and minor axis diameter compared with pressure‐diameter curves obtained before induction of failure. Neither inotropic nor chronotropic stimulation evoked such shifts. Assuming exponential pressure decline, LV relaxation was significantly slower during failure, but proceeded in all experimental conditions at rates which indicated complete relaxation in late diastole. Analysis of the pressure decline during LV relaxation demonstrated that this process proceeded faster than assumed by an exponential function both before and during LV failure.
Quantitative reticuloendothelial function of liver and spleen in man
Authors: Winkler K. , Skovgård L. T.
Published: April 2008

Summary. A method for separate determinations of liver and spleen reticuloendothelial function, using a small‐size 99Tcm‐antimony sulphide colloid and gamma camera technique, is described.

Several methods for achieving blood‐background correction are examined, and it is shown that, by a three‐compartment model, the use of a specific blood pool tracer can be dispensed with. Hepatic and splenic uptake of the colloid can be described by first order kinetics, and can be calculated to an error less than 5%. In a reference material (n=13), hepatic and splenic clearance was 262 ml/min (100412) and 22 ml/min (0–62), respectively. In cirrhosis (n=7), hepatic clearance was decreased and splenic clearance increased.

The results indicate that this method, which is well suited for clinical studies and which is based on a reasonable physiologic model, in cirrhosis of the liver demonstrates a decreased hepatic reticuloendothelial function with (compensatory?) increase in that of the spleen.
Effect of immobilization of short duration on the muscle fibre size
Authors: Lindboe Christian Fredrik , Platou Christian Stoud
Published: April 2008

Summary. In 10 patients with unilateral knee joint lesions, the injured leg was immobilized for 72 h by a plaster cast reaching from the hip to the ankle. At removal of the casts, open muscle biopsies were taken from the vastus medialis muscle on both sides. The muscle specimens were stained for myofibrillar ATPase activity and muscle fibre areas were measured on transverse sections. The differences in fibre size between the two sides were registered and statistically evaluated.

The reduction in fibre size on the immobilized side was 14.4% for the type 1 fibres and 17.3% for the type 2 fibres, respectively. However, these differences were not significant because of considerable variations from case to case, with an increase in fibre size on the immobilized side in three cases.

It is concluded that short time post‐traumatic immobilization may have variable effects on the muscle fibre size and that one single biopsy might be insufficient to disclose early disuse atrophy whereas the method may be useful in cases of longer duration.
Long‐term monitoring of arterial pO2 in burned patients
Authors: Nilsson Erling , Arnandery Claes
Published: April 2008

Summary. Five patients, who were treated in a special ward for bums were followed by continuous intra‐arterial pO2 monitoring for a total of 1612 h (range 13–604 h). The pao2 catheter electrodes used were surface‐heparinized, and inserted either in the radial or the femoral artery. Some electrodes were accidentally withdrawn. Recalibration was performed for two of the 10 electrodes used. These electrodes presented a changed sensitivity after heavy stretching of the sensor during the nursing. The sensitivity of one of these electrodes was altered downwards and the other one upwards. After recalibration the pao2 electrodes presented accurate values for the rest of the monitoring period. Without compensation for drift, the pao2 electrode readout was compared to the results of traditional blood‐gas analysis, which served as a reference. The regression function found was y = ‐0·62+ 1·04x (r=0·93, SD=1·40, n=60).

The blood flow velocity around some of the pao2 electrodes was studied by the pulsed Doppler technique. There was no influence of the surface‐heparinked pao2 electrode on the femoral artery blood flow velocity as compared to the contralateral, non‐catheterized femoral artery. The blood flow velocity proximal to a traditional radial artery catheter was compared to the flow velocity in the contralateral radial artery containing a surface‐heparinized pao2 electrode. The surface‐heparinked electrode did not decrease the mean flow velocity in contrast with the traditional radial artery catheter, which had to be withdrawn after 8 days because of clotting. The surface‐heparinized catheter electrode was still monitoring pao2 accurately after 25 days in the artery, which was the longest period studied for a particular sensor.
Overestimation of inspiratory upper airway resistance
Authors: Bake B. , Ejnell H. , Sixt R. , Månsson I.
Published: April 2008

Summary. Inspiratory resistance was found to be 10–50% larger than the expiratory in a model of the upper airways. This was most likely caused by a high kinetic energy component in the airstream close to the constriction reducing the lateral pressure in excess of what could be explained by the frictional pressure drop. Consequently, the inspiratory resistance was overestimated. During expiratory flow, on the other hand, the kinetic energy component at the same site in the trachea was smaller and similar to that in the mouthpiece resulting in an apparently adequate assessment of expiratory resistance. These results may explain why previous authors have found equal inspiratory and expiratory upper airway resistance although the vocal cords abduct during inspiration and adduct during expiration. Pressures obtained by means of the tracheal puncture appeared to be more reliable compared to those obtained from puncture of the cricothyroid membrane.
The effect of phototherapy on extracellular water and transvascular protein exchange in psoriasis
Authors: Staberg Bent
Published: April 2008

Summary.Seven patients with stable psoriasis vulgaris were treated with phototherapy (Goeckerman or PUVA) for 3 to 4 weeks. By combining the suction blister technique with studies on labelled albumin and inulin, the intra‐ and extravascular fluid volumes, the leakage of albumin from the total and the skin microvasculature, and the intra‐ and extravascular masses of albumin were measured before and after therapy. In accordance with previous studies, a shift of fluid from the intra‐ to the extravascular spaces, an increased leakiness of the involved skin microvasculature, and a lowered total mass of body albumin were found before therapy. Treatment induced a minor increase of the extracellular fluid volume [mean, 6·20 ± 1·16 l/m2(SD)v.6·73 ± 0·95 l/m2(SD),P< 0·1], a reduced vascular leakage of albumin from the involved skin vessels, and a significant increase of the total mass of albumin [mean, 124±20 g/m2(SD)v.139 ± 30 g/m2(SD),P< 0·05]. The other measured variables did not change significantly. It is suggested that the observed change in extracellular fluid volume was mainly due to a treatment‐induced decrease of the transepidermal water loss and/or a subclinical oedema of the skin, whereas the increase in total albumin mass was due to a reduction of the catabolism of the endogenous albumin caused by the decrease in the microvascular leakiness of the involved skin vessels.
Interstitial colloid osmotic and hydrostatic pressures in human subcutaneous tissue during early stages of heart failure
Authors: Noddeland Harald , Omvik Per , Lund‐Johansen Per , Ofstad Jarle , Aukland Knut
Published: April 2008

Summary. Subcutaneous oedema is a common finding in heart failure. However, some patients have reduced cardiac pump function without oedema. The aim of this study was to investigate whether local mechanisms in subcutaneous tissue contribute to oedema prevention. A reduction in interstitial colloid osmotic pressure (φi) and a rise in interstitial fluid hydrostatic pressure (Pi) will both counteract a rise in capillary filtration caused by heart failure. Cardiac catheterization was done in 22 angina pectoris patients without visible oedema. Two days later φi was measured with a wick method and Pi was measured with a wick‐in‐needle method. Both parameters were measured in subcutaneous tissue on thorax at heart level and on the ankle. Plasma volume was determined by 125I‐albumin and extracellular volume measured with 35SO4. Parameters of cardiac pump function ranged from normal to clearly pathological values. Mean φi was 13·0 mmHg on thorax and 8·3 mmHg on the ankle. Pi, averaged ‐2·1 mmHg on thorax and ‐1·5 mmHg on the ankle. Statistically significant (P<0·05) correlations were found between φi on thorax and left ventricular end diastolic pressure (rs ‐0·40) and φi on thorax and cardiac index (rs 0·42). Pi, was positively correlated to right atrial pressure (rs 0·50). Body fluid volumes were normal or moderately reduced. The study shows that a reduction in cardiac pump function is associated with a reduction in φi and a rise in Pi. These changes may help to prevent oedema formation in the early stages of heart failure.
Free amino acids in muscle tissue and plasma during exercise in man
Authors: Bergström Jonas , Fürst Peter , Hultman Eric
Published: April 2008

Summary. Blood and muscle samples (percutaneous biopsy of m. quadriceps femoris) were taken before exercise and after 10 and 20 min of exercise in four healthy subjects working on a bicycle ergometer with a load of 70% of VO2 max. Free amino acids were determined in plasma and muscle and the intracellular concentration of each amino acid was calculated by the chloride method. The plasma concentration of alanine, arginine and glutamine increased during exercise. In muscle there was an increase in glutamine and alanine concentration and a decrease in glutamate concentration at 10 min of exercise; after 20 min of exercise the increase in alanine and glutamine concentrations was less marked, but the decrease in glutamate concentration was of a similar magnitude. The results demonstrate that glutamate is a quantatively important ammonia acceptor during heavy exercise.