Opposite circadian rhythms in melatonin and tissue factor pathway inhibitor type 1: does daylight affect coagulation?
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Blood Coagulation↗
Biomedical subjects
N Hjeltnes
Publications and source records attributed to N Hjeltnes.
Effect of training intensity on physical capacity, lipid profile and insulin sensitivity in early rehabilitation of spinal cord injured individuals.
STUDY DESIGN: Pre-post training intervention. OBJECTIVES: To evaluate the effect of training intensity on physical capacity, lipid profile and insulin sensitivity in early rehabilitation of spinal cord injured (SCI) patients, and to assess the correlation between peak aerobic capacity (VO(2Peak)) and insulin sensitivity. SETTING: Spinal Cord Rehabilitation Unit, Sunnaas Hospital, Nesoddtangen, Norway. METHOD: Six recently injured SCI individuals participated in the arm training intervention and were randomly admitted to a high-intensity (HI; 70-80% heart rate reserve (HRR)) and low-intensity (LI; 40-50% HRR) group. The 1 h interval training consisted of 3 min exercise bouts interspersed with 2 min of rest, three times a week for 8 weeks. In addition, a correlation coefficient was obtained between VO(2Peak) and insulin sensitivity in 11 SCI patients. RESULTS: The 8-week training program resulted in a significant increase in VO(2Peak) and maximal power output (PO(Max)) for the group as a whole (P<0.05). VO(2Peak) increased significantly more and total cholesterol/high-density lipoprotein cholesterol (TC/HDL-C) ratio and triglycerids decreased significantly more in the HI group than in the LI group (P=0.05). Training-induced changes in insulin sensitivity were significantly different between the groups (P=0.05), which was due to a nonsignificant decline in insulin sensitivity in the HI group and a nonsignificant improvement in the LI group. A significant positive correlation was found between VO(2peak) and insulin sensitivity (r=0.68, P=0.02). CONCLUSION: The interval arm training protocol as used in the present study enables recently injured SCI patients to do substantial work at a relatively high intensity. Results indicate that improvements in physical capacity and lipid profile were more pronounced in response to high-intensity training. The significant correlation between maximal oxygen consumption and insulin sensitivity indicates that, as in the able-bodied population, peak aerobic capacity is a predictive value with regard to insulin sensitivity in SCI. Future studies with larger groups assessing the role of exercise intensity on insulin sensitivity in SCI are suggested.
Activities of Daily Living↗
Altered glycogen synthase and phosphorylase activities in skeletal muscle of tetraplegic patients.
Despite marked differences in both the extent of physical activity and in muscle metabolism and structure between tetraplegic and control subjects, the glycogen content in the skeletal muscle of both groups is similar. We determined whether this similarity could be explained by the activities of key enzymes of glycogen metabolism. Muscle biopsies were analysed for glycogen synthase (GS) and glycogen phosphorylase (GP) activities, as well as for metabolites. Glycogen content did not differ significantly between the two groups. Total glycogen synthase activity was reduced by almost 60 % in tetraplegics (P < 0.01), whereas total phosphorylase activity did not differ between groups. GS fractional activity did not differ between groups, whereas phosphorylase fractional activity (-/+ AMP) was significantly higher in the tetraplegics (0.08 +/- 0.01, control; 0.25 +/- 0.02, tetraplegics; P < 0.001). Neither uridine diphosphate (UDP)-glucose nor glucose 6-phosphate (G-6-P) content in muscle differed significantly between groups. These data demonstrate that, in tetraplegics, muscle glycogen content is preserved despite decreases in GS activity and increases in phosphorylase fractional activity. Muscle paralysis has differential effects on the activities of GS and GP. Experimental Physiology (2001) 86.2, 205-209.
Adult↗
Depressed immunity and impaired proliferation of hematopoietic progenitor cells in patients with complete spinal cord injury.
The bone marrow is supplied with both sensory and autonomic neurons, but their roles in regulating hematopoietic and immunocompetent cells are unknown. Leukocyte growth and activity in patients with stable and complete spinal cord injuries were studied. The innervation of the bone marrow below the injury level lacked normal supraspinal activity, that is, a decentralized bone marrow. Lymphocyte functions were markedly decreased in injured patients. Long-term colony formation of all hematopoietic cell lineages, including dendritic cells, by decentralized bone marrow cells was substantially reduced. It was concluded that nonspecific and adaptive lymphocyte-mediated immunity and growth of early hematopoietic progenitor cells are impaired in patients with spinal cord injuries. Possibly, this reflects cellular defects caused by the malfunctioning neuronal regulation of immune and bone marrow function.
Adult↗
Regulation of UCP2 and UCP3 by muscle disuse and physical activity in tetraplegic subjects.
AIMS/HYPOTHESIS: The regulation of uncoupling protein 2 and uncoupling protein 3 gene expression in skeletal muscle has recently been the focus of intense interest. Our aim was to determine expression of uncoupling protein 2 and 3 in skeletal muscle from tetraplegic subjects, a condition representing profound muscle inactivity. Thereafter we determined whether exercise training would modify expression of these genes in skeletal muscle. METHODS: mRNA expression of uncoupling protein 2 and 3 was determined using quantitative reverse transcription-polymerase chain-reaction. RESULTS: Expression of uncoupling protein 2 and 3 mRNA was increased in skeletal muscle from tetraplegic compared with able-bodied subjects (3.7-fold p < 0.01 and 4.1-fold, p < 0.05, respectively). A subgroup of four tetraplegic subjects underwent an 8-week exercise programme consisting of electrically-stimulated leg cycling (ESLC, 7 ESLC sessions/week). This training protocol leads to increases in whole body insulin-stimulated glucose uptake and expression of genes involved in glucose metabolism in skeletal muscle from tetraplegic subjects. After ESLC training, uncoupling protein 2 expression was reduced by 62% and was similar to that in able-bodied people. Similarly, ESLC training was associated with a reduction of uncoupling protein 3 expression in skeletal muscle from three of four tetraplegic subjects, however, post-exercise levels remained increased compared with able-bodied subjects. CONCLUSION/INTERPRETATION: Tetraplegia is associated with increased mRNA expression of uncoupling protein 2 and 3 in skeletal muscle. Exercise training leads to normalisation of uncoupling protein 2 expression in tetraplegic subjects. Muscle disuse and physical activity appear to be powerful regulators of uncoupling protein 2 and 3 expression in human skeletal muscle.
Adult↗
Improved work capacity but unchanged peak oxygen uptake during primary rehabilitation in tetraplegic patients.
Individuals with cervical spinal cord lesions are characterised by markedly decreased aerobic capacity, accompanied by increased risk of developing cardiovascular disease. The aim of this study was to evaluate the effects of a primary rehabilitation programme that included three sessions of arm cycling per week on the endurance capacity in 10 male tetraplegic subjects (injury level C6-C8; eight ASIA-A and two ASIA-B). Peak oxygen uptake (peak VO2) was measured three times (at T1 approximately 99 +/- 10 days after injury. T2 approximately 2 months after T1, and at T3 approximately 2 months after T2). Ten paraplegic patients admitted to the hospital for primary rehabilitation served as controls. In the tetraplegic patients, mean peak load increased (22 +/- 2, 32 +/- 5, and 32 +/- 7 watt, at T1, T2 and T3 respectively) (P < 0.01), while mean peak VO2 did not change during the study (0.78 +/- 0.07, 0.86 +/- 0.08, and 0.81 +/- 0.06 1 x min-1, at T1, T2 and T3, respectively) (ns). In contrast peak VO2 was significantly higher in the paraplegic control group (1.37 +/- 0.08, 1.64 +/- 0.10 and 1.75 +/- 0.08 1 x min-1, respectively) (P < 0.001), and increased significantly during the study period (P < 0.001). Mean heart rate (HR) and mean stroke volume (SV), measured at corresponding submaximal work loads during the study did not change significantly in the tetraplegic patients. Mean systolic blood pressure (SBP), recorded immediately after peak arm exercise was low at all three tests (93 +/- 8, 89 +/- 6 and 84 +/- 6 mmHg) in the tetraplegic group. However, both muscle strength and 'activities of daily life' index improved significantly during the study period. Our results suggest that functional improvement in tetraplegic patients is not necessarily followed by aerobic metabolic improvement. We conclude that more time should be spent on arm endurance training, or training methods which activate larger muscle groups and/or increases blood pressure.
Adult↗
Exercise-induced overexpression of key regulatory proteins involved in glucose uptake and metabolism in tetraplegic persons: molecular mechanism for improved glucose homeostasis.
Complete spinal cord lesion leads to profound metabolic abnormalities and striking changes in muscle morphology. Here we assess the effects of electrically stimulated leg cycling (ESLC) on whole body insulin sensitivity, skeletal muscle glucose metabolism, and muscle fiber morphology in five tetraplegic subjects with complete C5-C7 lesions. Physical training (seven ESLC sessions/wk for 8 wk) increased whole body insulin-stimulated glucose uptake by 33+/-13%, concomitant with a 2.1-fold increase in insulin-stimulated (100 microU/ml) 3-O-methylglucose transport in isolated vastus lateralis muscle. Physical training led to a marked increase in protein expression of GLUT4 (378+/-85%), glycogen synthase (526+/-146%), and hexokinase II (204+/-47%) in vastus lateralis muscle, whereas phosphofructokinase expression (282+/-97%) was not significantly changed. Hexokinase II activity was significantly increased, whereas activity of phosphofructokinase, glycogen synthase, and citrate synthase was not changed after training. Muscle fiber type distribution and fiber area were markedly altered compared to able-bodied subjects before ESLC training, with no change noted in either parameter after ECSL training. In conclusion, muscle contraction improves insulin action on whole body and cellular glucose uptake in cervical cord-injured persons through a major increase in protein expression of key genes involved in the regulation of glucose metabolism. Furthermore, improvements in insulin action on glucose metabolism are independent of changes in muscle fiber type distribution.
3-O-Methylglucose↗
Improved body composition after 8 wk of electrically stimulated leg cycling in tetraplegic patients.
The practical aspects of utilizing electrically stimulated leg cycling (ESLC) to counteract alterations in body composition were investigated in five tetraplegic subjects with long-standing complete spinal cord injuries (C5-C7). After a 2-wk adaptation period, the subjects performed seven ESLC sessions per week for 8 wk. No adverse reactions were noted in response to the ESLC program. The ESLC sessions were accompanied by higher lactate concentrations compared with arm exercise. Heart rate and blood pressure response revealed clear, but not serious, signs of autonomic dysreflexia in the beginning of the ESLC sessions. Body temperature increased moderately during the ESLC sessions. Peak oxygen uptake (Vo2) during an ESLC session increased by 70% (P < 0.05) after 8 wk of training. Body composition, evaluated by dual-energy X-ray absorptiometry (DEXA), demonstrated an increase in lean body mass (LBM) from 66.2 +/- 2.6 to 68.2 +/- 2.1% (P < 0.05), with a concomitant decrease in whole body fat (BF) content from 29.7 +/- 2.6 to 27.8 +/- 2.1% (P < 0.05) after training. The cross-sectional area of quadriceps, hamstrings, gluteus maximus, and gluteus medius muscles, measured by computer tomographic scans, increased from 267 +/- 27 to 324 +/- 27 cm2 (P < 0.05) after the training. In conclusion, daily ESLC sessions during a 2-mo period resulted in increased LBM, decreased BF content, and increased muscular endurance in tetraplegic subjects without any noticeable adverse effects.
Absorptiometry, Photon↗
Intact glucose transport in morphologically altered denervated skeletal muscle from quadriplegic patients.
The present study was undertaken to investigate the nature of the whole body insulin resistance that characterizes patients with complete cervical spinal cord lesion. Nine patients with C5-C7 lesions and ten age-matched healthy individuals were studied. Whole body insulin-mediated glucose utilization was reduced by 43% in the quadriplegic patients compared with the controls (P < 0.001). In the quadriplegic patients, lean body mass corresponded to 66 +/- 3% of total body mass. Despite whole body insulin resistance, in isolated vastus lateralis muscle, basal and insulin-stimulated 3-O-methylglucose transport, as well as protein expression of the insulin or exercise-regulatable glucose transporter, GLUT-4, and glycogen content were comparable between the patients and controls. Strikingly, muscle fiber area was reduced by 44% (P < 0.05), percentage of type IIb fibers was increased (P < 0.01), and there was a complete loss of type I fibers in the patients. In conclusion, the dissociation between whole body insulin-mediated glucose uptake and skeletal muscle glucose transport in quadriplegic patients primarily reflects the decreased muscle mass. Furthermore, these findings demonstrate a remarkable capacity of skeletal muscle to maintain an intact glucose transport system despite severe morphological alterations.
Adult↗
[Bladder problems after traumatic spinal cord injuries].
Patients with a recent traumatic spinal cord lesion admitted consecutively to Sunnaas Rehabilitation Hospital during the five-year period from 1987 to 1991 were included in a study of bladder function, including results of urodynamic investigation and urological complications, both during primary rehabilitation and on average five years (two to nine years) after injury. Indication for urodynamic investigation was found in 125 out of 170 patients. The study shows that micturition is a major problem after spinal cord injury, and that the follow-up programme after the rehabilitation period should be improved. General practitioners should be aware of these problems. Close cooperation between the rehabilitation department and the primary health service is needed to avoid renal and urinary complications in these patients.
Adolescent↗
[Cystometry in neurogenic bladder disorders. Methodologic problems and assessment of risk of renal complications].
Patients with neurogenic bladder dysfunction may have an elevated detrusor pressure during the filling or emptying phase, which may result in upper urinary tract dysfunction. Cystometric examination is important in order to evaluate the risk of such complications and the effect of therapeutic intervention. If compliance is low, the cystometric filling rate has to be slow in order to obtain a physiologically representative pressure. In the case of detrusor hyperreflexia, intraindividual variation makes it necessary to perform repeated filling of the bladder in order to get representative values for the amplitude and duration of the detrusor contraction. The clinical significance of these methodological problems is discussed.
Humans↗
Residual urine following intermittent catheterisation in patients with spinal cord injuries.
Residual urine following catheterisation was studied using ultrasonography (Ultramark II Scientific Medical System) in 12 patients with spinal cord injury, for an average of 4 months (range 3-7 months) after the time of injury. All of the patients were examined on three occasions. Urinary tract infections were also registered, and the functional type of the urinary bladder was identified by a cystometric examination. Ultrasonography showed residual urine volumes after 25 of a total of 36 catheterisations (70%). In seven of these catheterisations the residual urine volume exceeded 50 ml, and in two patients was more than 100 ml. None of the patients had a residual urinary volume of more than 50 ml after all three catheterisations, but in all but two patients, some residual urine volume was found after at least one of the catheterisations. Low and non-significant correlations were found between residual volume and frequency of urinary tract infections. It is possible that even small residual urine volumes after catheterisations may predispose to urinary tract infections in these patients.
Adolescent↗
Metabolic, thermal and circulatory effects of intravenous infusion of amino acids in tetraplegic patients.
Metabolic, circulatory and thermal effects of intravenously (i.v.) administered amino acids were studied in eight patients with complete cervical spinal cord injuries, and compared with the effects in eight healthy subjects. Using indirect calorimetry and catheter techniques, whole-body and splanchnic oxygen consumption, blood flow and blood temperatures were measured before and at timed intervals during 2.5 h of i.v. infusion of 600 kJ of a mixture of 19 amino acids. Pulmonary oxygen uptake increased from 209 +/- 11 to 267 +/- 13 ml min-1 in the patients and from 268 +/- 5 to 320 +/- 8 ml min-1 in the controls. The thermic effect of amino acids was 21 +/- 3% and 16 +/- 2% in patients and controls, respectively. In both groups the splanchnic tissues accounted for approximately half of the rise in whole-body oxygen consumption. Cardiac output rose by, on average, 0.5 +/- 0.1 and 0.8 +/- 0.2 1 min-1 in patients and controls, respectively, while the hepatic blood flow remained unchanged in both groups. Pulmonary arterial blood temperature increased by 0.647 +/- 0.100 degrees C in the patients and by 0.244 +/- 0.174 degrees C in the controls (P < 0.05). The whole-body specific heat was low in the patients, its calculated maximum value being approximately 20% below the normal level. During the amino acid infusion the arterial blood concentration of amino acids rose by approximately 170% and 112% of its basal levels in patients and controls, respectively, indicating a significantly reduced capacity for cellular uptake of amino acids in tetraplegic patients. It is concluded that, in tetraplegic patients, i.v. infused amino acids induce prompt thermogenesis of normal magnitude accompanied by supranormal temperatures and amino acid concentrations in the blood, and that low whole-body specific heat contributes to the well-known thermoregulatory instability in tetraplegia.
Adult↗
Glucose-induced thermogenesis in tetraplegic patients with low sympathoadrenal activity.
The influence of the sympathoadrenal system on the thermic effect of glucose was examined by studying six tetraplegic patients with complete lesions of the cervical spinal cord. Indirect calorimetry and catheter techniques were employed, and measurements were made before and during 2 h after oral ingestion of 75 g of glucose. The results were compared with previous findings from an identical study in healthy subjects and with those from a control group of five tetraplegic patients receiving water instead of glucose. In response to glucose, energy expenditure rose from 69 +/- 5 to 79 +/- 5 and from 88 +/- 3 to 98 +/- 4 W, (not significant) in the patients and healthy subjects, respectively. In both patients and the healthy subjects the postprandial oxygen consumption increased exclusively in extrasplanchnic tissues. Splanchnic blood flow, which in normals increased 34 +/- 1%, did not change in the patients after glucose. Blood temperatures were unchanged in normals after glucose but rose by approximately 0.5 degrees C in the patients. The patients' arterial plasma concentrations of norepinephrine were low in the basal state and did not rise significantly after glucose. The arterial blood glucose concentrations after glucose were significantly higher in the patients than in the healthy subjects. Insulin levels rose to 105 +/- 20 mU/l in the patients and to 59 +/- 7 mU/l in the controls (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
Adrenal Glands↗
[Residual urine after intermittent catheterization in patients with spinal cord injuries].
Residual urine following catheterization was studied using ultrasonography (Ultramark II Scientific Medical System) in 12 patients with spinal cord injury, for an average of four months (range 3-7 months) after time of injury. All patients were examined three times. Urinary tract infections were also registered, and the functional type of the urinary bladder was identified by cystometric examination. Ultrasonography showed residual urine volumes after 25 of a total of 36 catheterizations (70%). In seven of these catheterizations the residual urine volume exceeded 50 ml, and in two cases was more than 100 ml. None of the patients had a residual urinary volume of more than 50 ml after all three catheterizations, but in all but two patients, some residual urine volume was found after at least one of the catheterizations. Low and non-significant correlations were found between residual volume and frequency of urinary tract infections. It is possible that even small residual urine volumes after catheterization may predispose for urinary tract infections in these patients.
Adolescent↗
Meal-induced rise in resting energy expenditure in patients with complete cervical spinal cord lesions.
Central activation of the sympathoadrenal system is generally considered to be an essential component of the mechanisms whereby food ingestion stimulates resting energy expenditure. The functional importance of such sympathoadrenal stimulation has been demonstrated primarily in animals. To the extent that central sympathoadrenal stimulation is required for normal human nutrient-induced thermogenesis, this process should be defective in patients with complete cervical spinal cord lesion and severed connection between the central nervous system and the peripheral sympathetic nerves. Consequently, respiratory gas exchange was measured by indirect calorimetry in 9 tetraplegic patients and in 6 healthy individuals. Measurements were performed before and 2 hours after ingestion of a standardised mixed meal (40% of basal 24 h energy requirements). The basal energy expenditure was 64 +/- 4 watts in the tetraplegic patients and 79 +/- 6 watts in the controls. After the meal, energy expenditure increased on average by 17 +/- 2 watts or 26 +/- 3% of the basal values in the patients and by 14 +/- 2 watts or 19 +/- 3% in the healthy controls (NS). The thermic effect of the meal, ie the rise in energy expenditure expressed in percent of the meal's energy content, was 5.5 +/- 0.7% in the patients and 3.8 +/- 0.6% in the controls (NS). Plasma concentrations of noradrenaline were low in the tetraplegic patients (0.3-0.4 nmol/l) compared to the healthy controls (1.1-1.4 nmol/l), p < 0.02. It is concluded that nutrient-induced thermogenesis in tetraplegic patients with low sympathoadrenal activity is not diminished compared to healthy controls. The findings indicate that efferent sympathoadrenal stimulation from the brain is not a causal necessity for nutrient-induced thermogenesis in man.
Adult↗
Lung volumes in tetraplegic patients according to cervical spinal cord injury level.
Fifty-six tetraplegic patients with motor complete lesions (Frankel A and B) underwent spirometric measurements more than 6 months after injury. The results were evaluated according to the level of transection of the cervical cord. A pronounced restrictive respiratory dysfunction was demonstrated in all patients. The expiratory reserve volume (ERV) was zero or markedly reduced in patients at all lesion levels. Systematic increases in both ERV and vital capacity (VC) were found with lower lesion level. The inspiratory capacity (IC) was reduced at all injury levels, but there were no systematic differences in IC between injury levels C4-C8. The total lung capacity (TLC) was reduced and the ratio residual volume/total lung capacity (RV/TLC) was increased in patients at all injury levels. The lung function of patients tested > 12 months after injury was not significantly different from the function in those tested 6-12 months after injury. A respiratory rehabilitation programme for tetraplegic patients should take into account the fact that the respiratory function, especially the forced expiration, is dependent upon injury level.
Adolescent↗
Functional neuromuscular stimulation in 4 patients with complete paraplegia.
The effect of functional neuromuscular stimulation (FNS) on muscle strength and endurance was studied in 3 patients with long-standing complete injuries (T7-T12) and in 1 patient with a recent complete injury (T5). All 4 patients became strong enough to rise, stand and to walk a few steps within parallel bars. However, only 1 patient was able to walk without parallel bars (60 m). The energy demand of FNS-assisted walking was measured to be more than 60% of the maximal endurance capacity of this patient. This finding partly explains the low patient acceptance of FNS.
Adult↗