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Dencker M, Thorsson O, Karlsson MK, Lindén C, Svensson J, Wollmer P, Andersen LB. Daily physical activity in Swedish children aged 8-11 years. Scand J Med Sci Sports 2006; 16:252-7. [PMID: 16895530 DOI: 10.1111/j.1600-0838.2005.00486.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Physical inactivity is hypothesized to be a contributing factor in the development of a variety of diseases. Recommendations for an adequate level of physical activity have been proposed. There are few studies in which the physical activity in children has been objectively assessed. The purpose of this study was to estimate objectively the level of physical activity in Swedish children. MATERIALS AND METHODS We studied 248 children (140 boys and 108 girls) aged 7.9-11.1 years from Malmö, Sweden. Physical activity was measured with accelerometers. Children were instructed to wear the accelerometers for 4 days. The mean daily activity was expressed as the mean counts per minute of recording. The time that the child spent performing moderate or vigorous activity was calculated by using previously established cutoff points. RESULTS The mean daily activity was higher in boys than in girls, 751+/-243 vs 618+/-154 counts/min (P<0.001). All children fulfilled the recommendation for moderate physical activity for 60 min or more per day. Ninety-two percent of the boys and 86% of the girls performed vigorous activity, for 20 min or more per day. CONCLUSION All children, aged 8-11 years, who participated in this study reached the recommended level of physical activity, with boys being more active than girls.
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Peker Y, Svensson J, Hedner J, Grote L, Johannsson G. Sleep apnoea and quality of life in growth hormone (GH)-deficient adults before and after 6 months of GH replacement therapy. Clin Endocrinol (Oxf) 2006; 65:98-105. [PMID: 16817827 DOI: 10.1111/j.1365-2265.2006.02555.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To investigate the sleep architecture and breathing as well as quality of life (QoL) in adults with GH deficiency (GHD) before and 6 months after GH replacement therapy. DESIGN A prospective observational study. PATIENTS Nineteen consecutive adults with GHD (11 men, eight women; mean age 53, range 21-73 years) were studied. MEASUREMENTS An overnight sleep study was performed and the Minor Symptom Evaluation Profile (MSEP), Functional Outcome of Sleep Questionnaire (FOSQ), Short Form 36 (SF-36) and Epworth Sleepiness Scale (ESS) questionnaires were applied at baseline and after the treatment period. RESULTS For the whole group, there were no significant changes in mean total sleep time (TST; 370 min vs. 374 min), proportion of slow-wave sleep (SWS; 17.8%vs. 18.4%) and rapid eye movement (REM) sleep (12.1%vs. 13.9%) on GH replacement. Mean apnoea-hypopnoea index (AHI) was high and remained unchanged (28.2/h before vs. 28.0/h following GH replacement). Twelve patients (63%) were found to have obstructive sleep apnoea (OSA; AHI >or= 10/h) at baseline. Compared with GH-deficient patients without OSA (AHI 3.9/h), the OSA patients (AHI 42.4/h) had less SWS (11.4%vs. 28.6%, P = 0.010) and REM sleep (10.1%vs. 15.5%, P = 0.036). A marginal increase was observed in REM sleep time (10.1% before vs. 12.7% after GH; P = 0.048) while SWS was unchanged in this group. Moreover, MSEP for General Well-being and Responsiveness, FOSQ scores for General Productivity, Activity Level and Vigilance as well as SF-36 domains for Vitality and Mental Health were improved. CONCLUSIONS Contrary to some previous observations in a smaller group of patients, our data suggest that GH therapy does not induce or aggravate OSA in GH-deficient adults. Moreover, GH therapy may improve some of the QoL dimensions in these patients.
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Svensson J, Diez M, Engel J, Wass C, Tivesten A, Jansson JO, Isaksson O, Archer T, Hökfelt T, Ohlsson C. Endocrine, liver-derived IGF-I is of importance for spatial learning and memory in old mice. J Endocrinol 2006; 189:617-27. [PMID: 16731792 DOI: 10.1677/joe.1.06631] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
IGF-I is a neuroprotective hormone, and neurodegenerative disorders, including Alzheimer's disease, have been associated with decreased serum IGF-I concentration. In this study, IGF-I production was inactivated in the liver of adult mice (LI-IGF-I(-/-)), resulting in an approximately 80-85% reduction of circulating IGF-I concentrations. In young (6-month-old) mice there was no difference between the LI-IGF-I(-/-) and the control mice in spatial learning and memory as measured using the Morris water maze test. In old (aged 15 and 18 months) LI-IGF-I(-/-) mice, however, the acquisition of the spatial task was slower than in the controls. Furthermore, impaired spatial working as well as reference memory was observed in the old LI-IGF(-/-) mice. Histochemical analyses revealed an increase in dynorphin and enkephalin immunoreactivities but decreased mRNA levels in the hippocampus of old LI-IGF-I(-/-) mice. These mice also displayed astrocytosis and increased metabotropic glutamate receptor 7a-immunoreactivity. These neurochemical disturbances suggest synaptic dysfunction and early neurodegeneration in old LI-IGF-I(-/-) mice. The decline in serum IGF-I with increasing age may therefore be important for the age-related decline in memory function.
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Lindberg MK, Svensson J, Venken K, Chavoshi T, Andersson N, Movérare Skrtic S, Isaksson O, Vanderschueren D, Carlsten H, Ohlsson C. Liver-derived IGF-I is permissive for ovariectomy-induced trabecular bone loss. Bone 2006; 38:85-92. [PMID: 16257281 DOI: 10.1016/j.bone.2005.07.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Revised: 05/26/2005] [Accepted: 07/08/2005] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Estrogen deficiency results in trabecular bone loss, associated with T-cell proliferation in the bone marrow. Insulin-like growth factor I (IGF-I) is involved in the regulation of both bone metabolism and lymphopoiesis. A major part of serum IGF-I is derived from the liver. The aim of the present study was to investigate the role of liver-derived IGF-I for ovariectomy (ovx)-induced trabecular bone loss. MATERIALS AND METHODS Mice with adult liver-specific IGF-I inactivation (LI-IGF-I-/-) and wild type mice (WT) were either ovx or sham operated. After 5 weeks, the skeletal phenotype was analyzed by pQCT and microCT. The bone marrow cellularity was analyzed using FACS technique, and mRNA levels were quantified using real-time PCR. RESULTS Ovx resulted in a pronounced reduction in trabecular bone mineral density (-52%, P < 0.001), number (-45%, P < 0.01) and thickness (-13%, P < 0.01) in WT mice while these bone parameters were unaffected by ovx in LI-IGF-I-/- mice. Furthermore, ovx increased the number of T-cells in the bone marrow of the femur in WT but not in LI-IGF-I-/- mice. Interleukin 7 (IL-7) has been reported to stimulate the formation and function of osteoclasts by inducing the expression of receptor activator of NF-kappaB ligand (RANKL) on T-cells. IL-7 mRNA levels and the RANKL/osteoprotegerin ratio in bone were increased by ovx in WT but not in LI-IGF-I-/- mice. CONCLUSIONS Liver-derived IGF-I is permissive for ovx-induced trabecular bone loss. Our studies indicate that IGF-I might exert this permissive action by modulation of the number of T-cells and the expression of IL-7, which in turn is of importance for the RANKL/OPG ratio and consequently osteoclastogenesis in the bone marrow.
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Eiberg S, Hasselstrom H, Grønfeldt V, Froberg K, Svensson J, Andersen LB. Maximum oxygen uptake and objectively measured physical activity in Danish children 6-7 years of age: the Copenhagen school child intervention study. Br J Sports Med 2005; 39:725-30. [PMID: 16183768 PMCID: PMC1725036 DOI: 10.1136/bjsm.2004.015230] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES To provide normative data on maximum oxygen uptake (Vo(2)max) and physical activity in children 6-7 years of age and analyse the association between these variables. METHODS Vo(2)max was measured in 366 boys (mean (SD) 6.8 (0.4) years of age) and 332 girls (6.7 (0.4) years of age) from preschool classes in two suburban communities in Copenhagen, during a progressive treadmill exercise. Habitual physical activity was measured with accelerometers. RESULTS Boys had higher Vo(2)max both in absolute values (1.19 (0.18) v 1.06 (0.16) litres/min (+11%), p<0.001) and relative to body weight (48.5 (6.0) v 44.8 (5.6) ml/kg/min (+8%); p<0.001) than girls. The difference in Vo(2)max between boys and girls decreased to +2% when expressed relative to lean body mass (LBM). Absolute Vo(2)max was related to LBM, body mass, and stature (all p<0.001). Boys were more physically active than girls (mean counts +9.4%, p<0.001), and even when boys and girls with the same Vo(2)max were compared, boys were more active. The difference in physical activity between the sexes was higher when sustained activity of higher intensity was compared. CONCLUSIONS Vo(2)max is higher in boys than girls (+11%), even when related to body mass (+8%) and LBM (+2%). Most of the difference in Vo(2)max relative to body mass was explained by the larger percentage body fat in girls. When boys and girls with the same Vo(2)max were compared, boys engaged in more minutes of exercise of at least moderate intensity.
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Svensson J, Tivesten A, Isgaard J. Growth hormone and the cardiovascular function. MINERVA ENDOCRINOL 2005; 30:1-13. [PMID: 15877009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In this review, the great importance of growth hormone (GH) for the maintenance of cardiac function in adult life is discussed. Physiological effects of GH are discussed as well as the cardiac dysfunction caused both by GH excess (acromegaly) and by GH deficiency in adult hypopituitary patients. In both acromegaly and adult GH deficiency, there is also increased cardiovascular morbidity and mortality. Finally, the effect of GH treatment in heart failure is discussed.
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Svensson J, Bengtsson BA, Rosén T, Odén A, Johannsson G. Malignant disease and cardiovascular morbidity in hypopituitary adults with or without growth hormone replacement therapy. J Clin Endocrinol Metab 2004; 89:3306-12. [PMID: 15240607 DOI: 10.1210/jc.2003-031601] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A retrospective comparison was performed between 1411 hypopituitary adults without GH replacement [mean age, 56.9 (sd 18.6) yr] and the normal population in terms of fatal and nonfatal morbidity. A similar prospective comparison was then made in 289 hypopituitary patients on long-term GH replacement [mean age, 47.6 (sd 14.8) yr; mean duration of GH treatment, 60 months]. In the 1411 hypopituitary patients without GH replacement, overall mortality (P < 0.001), and the rates of myocardial infarctions (P < 0.01), cerebrovascular events (P < 0.001), and malignancies (P < 0.001) were increased compared with the normal population. Colorectal cancer was the most common malignancy in this cohort (P < 0.001 vs. the background population). In the 289 hypopituitary patients on GH replacement, overall mortality and the rate of malignancies were similar to the normal population. In the hypopituitary adults on GH therapy, the rate of myocardial infarctions was lower than that in the background population (P < 0.05), and there was a tendency toward an increased rate of cerebrovascular events. In conclusion, overall mortality and the rate of myocardial infarctions were increased in hypopituitary patients without GH replacement. An increased rate of malignancies was observed in the hypopituitary adults without GH therapy, with a predominance of colorectal cancer. GH replacement appeared to provide protection from myocardial infarctions. The rate of cerebrovascular events tended to be increased also in hypopituitary adults on GH therapy.
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Johansson E, Månsson S, Wirestam R, Svensson J, Petersson JS, Golman K, Ståhlberg F. Cerebral perfusion assessment by bolus tracking using hyperpolarized13C. Magn Reson Med 2004; 51:464-72. [PMID: 15004786 DOI: 10.1002/mrm.20013] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cerebral perfusion was assessed with 13C MRI in a rat model after intravenous injections of the 13C-labeled compound bis-1,1-(hydroxymethyl)-1-13C-cyclopropane-D8 in aqueous solutions hyperpolarized by dynamic nuclear polarization (DNP). Since the tracer acted as a direct signal source, several of the problems associated with techniques based on traditional dynamic susceptibility contrast (DSC) MRI contrast agents were avoided. Maps of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were calculated. The MTT was determined to be 2.8 +/- 0.8 sec. However, arterial partial-volume effects in the animal model prevented accurate absolute quantification of CBF and CBV. It was demonstrated that depolarization of the hyperpolarized 13C tracer via relaxation and the imaging sequence had little influence on CBF assessment when the time resolution of the imaging sequence was short compared to the MTT. However, CBV and MTT were increasingly underestimated as MTT or the depolarization rate increased if depolarization was not taken into account. With a modified bolus-tracking theory depolarization could be compensated for, assuming that the depolarization rate was known. Three separate compensation methods were investigated experimentally and by numerical simulations.
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Svensson J, Lönn L, Johannsson G, Bengtsson BA. Effects of GH and insulin-like growth factor-I on body composition. J Endocrinol Invest 2003; 26:823-31. [PMID: 14964433 DOI: 10.1007/bf03345231] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this review, different methods to estimate body composition are discussed shortly. The effects by GH on total and visceral fat mass, lean mass, muscle strength and body water are described. Gender differences in the sensitivity to GH administration are reviewed. Finally, a short description of the effects of insulin-like growth factor-I (IGF-I) administration on body composition has been included.
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Svensson J, Monson JP, Vetter T, Hansen TK, Savine R, Kann P, Bex M, Reincke M, Hagen C, Beckers A, Ilondo MM, Zdravkovic M, Bengtsson BA, Korbonits M. Oral administration of the growth hormone secretagogue NN703 in adult patients with growth hormone deficiency. Clin Endocrinol (Oxf) 2003; 58:572-80. [PMID: 12699438 DOI: 10.1046/j.1365-2265.2003.01754.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Little is known of the usefulness of GH secretagogues (GHSs) in GH-deficient (GHD) adults. The objective of this study was to determine the number of responders to treatment with NN703 in GHD adults. DESIGN A multicentre, randomized, double-blind, and placebo-controlled study. PATIENTS Ninety-seven GHD adults were included. MEASUREMENTS The GH response before and after 1 week of oral treatment with NN703 (n = 83) or placebo (n = 14) was determined. The first and last dose of NN703 was 3 mg/kg, whereas the dose of NN703 was 1.5 mg/kg/day during the 6 days between the first and last doses. Furthermore, all 97 patients received 1 micro g/kg GH-releasing hormone (GHRH) 3 weeks after the last dose of NN703. RESULTS Serum GH peak and area under curve (AUC) values after the first NN703 administration were greater than those after placebo administration (P < 0.05). However, after correction for the lower body mass index (BMI) in the NN703 group, this difference lost statistical significance. After 1 week of therapy, GH peak and AUC values were similar following the final doses of NN703 and placebo. Serum peak and AUC values of other anterior pituitary hormones were similar between the NN703 and placebo groups both after the first and last administration of study drug. Nine of the 83 patients (11%) responded with a serum peak GH concentration >or= 5 micro g/l after the first and/or last NN703 administration, whereas no patient responded after placebo administration. Serum IGF-I was unaffected by 1-week NN703 treatment, whereas serum IGFBP-3 was increased (P < 0.05 vs. placebo) also after correction for BMI. Mean serum peak GH concentration after GHRH administration was 2.1 micro g/l (+/-0.3, SEM), which was higher than that after the first NN703 administration (1.32 +/- 0.3, P < 0.05). CONCLUSION NN703 administration was generally well tolerated. Eleven per cent of the GHD adult patients responded with a peak GH response >or= 5 micro g/l after the first and/or last administration of oral NN703. Although a majority of GHD adults will not respond to NN703, the present results suggest that oral NN703 treatment could be useful in some adult patients with moderately severe GHD. These patients may be identified by a test dose of GHS.
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Svensson J, Carstensen B, Mortensen HB, Borch-Johnsen K. Gender-associated differences in Type 1 diabetes risk factors? Diabetologia 2003; 46:442-3. [PMID: 12687347 DOI: 10.1007/s00125-003-1049-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2002] [Revised: 11/04/2002] [Indexed: 10/20/2022]
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Svensson J, Boguszewski CL, Shibata F, Carlsson B, Carlsson LMS, Bengtsson BA. The effect of treatment with the oral growth hormone (GH) secretagogue MK-677 on GH isoforms. Growth Horm IGF Res 2003; 13:1-7. [PMID: 12550076 DOI: 10.1016/s1096-6374(02)00138-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Growth hormone (GH) consists of several isoforms. We have studied the proportion, expressed as percentage of total GH concentration, of non-22kDa (non-22K) GH isoforms and 20K GH during 8-week oral treatment with MK-677 25mg daily in 12 obese males. The proportion of non-22K GH isoforms in peak total GH samples after the initial MK-677 administration was higher than that after 2 and 8 weeks (p<0.01 and p<0.05, respectively). In selected non-peak total GH samples after the initial MK-677 administration, however, the proportion of non-22K GH isoforms was similar to that in the peak total GH samples after 2 and 8 weeks. The proportion of 20K GH in 2-h samples after the initial MK-677 administration was lower than that after 2 and 8 weeks (p<0.01 and p<0.05, respectively). We concluded that the proportion of non-22K GH isoforms was higher in peak, but not in non-peak, total GH samples after the initial MK-677 administration than that observed after multiple doses. The proportion of 20K GH in 2-h samples after the initial MK-677 administration was lower than that after 2 and 8 weeks. These moderate changes in the proportion non-22K GH isoforms are likely of small importance for the clinical response to MK-677 treatment.
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Svensson J, Carlsson A, Ericsson UB, Westphal O, Ivarsson SA. Noonan's syndrome and autoimmune diseases. J Pediatr Endocrinol Metab 2003; 16:217-8. [PMID: 12713260 DOI: 10.1515/jpem.2003.16.2.217] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Dahlberg L, Roos E, Svensson J, Leander P, Tiderius C. Arthritis Res Ther 2003; 5:168. [DOI: 10.1186/ar969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Johansson E, Svensson J, Månsson S, Petersson JS, Olsson LE, Golman K, Ståhlberg F. Gradient echo imaging of flowing hyperpolarized nuclei: theory and phantom studies on 129Xe dissolved in ethanol. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2002; 159:68-75. [PMID: 12468305 DOI: 10.1016/s1090-7807(02)00117-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The influence of flip angle and flow velocity on the signal intensity achieved when imaging a hyperpolarized substance with a spoiled gradient echo sequence was investigated. The study was performed both theoretically and experimentally using hyperpolarized xenon dissolved in ethanol. Analytical expressions regarding the optimal flip angle with respect to signal and the corresponding signal level are presented and comparisons with thermally polarized substances are made. Both experimentally and theoretically, the optimal flip angle was found to increase with increasing flow velocity. Numerical calculations showed that the velocity dependence of the signal differs between the cases of hyperpolarized and thermally polarized substances.
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Svensson J. An MLP training algorithm taking into account known errors on inputs and outputs. Int J Neural Syst 2002; 12:369-79. [PMID: 12424808 DOI: 10.1142/s0129065702001266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2002] [Revised: 05/06/2002] [Accepted: 09/10/2002] [Indexed: 11/18/2022]
Abstract
A training algorithm is introduced that takes into account a priori known errors on both inputs and outputs in an MLP network. The new cost function introduced for this case is based on a linear approximation of the network function over the input distribution for a given input pattern. Update formulas, in the form of the gradient of the new cost function, is given for a MLP network, together with expressions for the Hessian matrix. This is later used to calculate error bars in a Bayesian framework. The error bars thus derived are discussed in relation to the more commonly used width of the target posterior predictive distribution. It will also be shown that the taking into account of known input uncertainties in the way suggested in this article will have a strong regularizing effect on the solution.
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Mansson S, Johansson E, Svensson J, Olsson LE, Stahlberg F, Petersson JS, Golman K. Echo-planar MR imaging of dissolved hyperpolarized 129Xe. Potential for MR angiography. Acta Radiol 2002. [DOI: 10.1034/j.1600-0455.2002.430503.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Månsson S, Johansson E, Svensson J, Olsson LE, Ståhlberg F, Petersson JS, Golman K. Echo-planar MR imaging of dissolved hyperpolarized 129Xe. Acta Radiol 2002; 43:455-60. [PMID: 12423454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
PURPOSE The feasibility of hyperpolarized 129Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. MATERIAL AND METHODS Hyperpolarized Xe gas was dissolved in ethanol, a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. RESULTS The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160+/-11 s and T2 approximately 20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. CONCLUSION Based on the SNR of the obtained Xe EPI images, it was estimated that rapid in vivo MRA with 129Xe may be feasible, provided that an efficient, biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129Xe.
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Wahlström J, Hagberg M, Johnson PW, Svensson J, Rempel D. Influence of time pressure and verbal provocation on physiological and psychological reactions during work with a computer mouse. Eur J Appl Physiol 2002; 87:257-63. [PMID: 12111287 DOI: 10.1007/s00421-002-0611-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/20/2002] [Indexed: 10/27/2022]
Abstract
The overall aim of this study was to investigate whether time pressure and verbal provocation has any effect on physiological and psychological reactions during work with a computer mouse. It was hypothesised that physiological reactions other than muscle activity (i.e. wrist movements, forces applied to the computer mouse) would not be affected when working under stressful conditions. Fifteen subjects (8 men and 7 women) participated, performing a standardised text-editing task under stress and control conditions. Blood pressure, heart rate, heart rate variability, electromyography, a force-sensing computer mouse and electrogoniometry were used to assess the physiological reactions of the subjects. Mood ratings and ratings of perceived exertion were used to assess their psychological reactions. The time pressure and verbal provocation (stress situation) resulted in increased physiological and psychological reactions compared with the two control situations. Heart rate, blood pressure and muscle activity in the first dorsal interosseus, right extensor digitorum and right trapezius muscles were greater in the stress situation. The peak forces applied to the button of the computer mouse and wrist movements were also affected by condition. Whether the increases in the physiological reactions were due to stress or increased speed/productivity during the stress situation is discussed. In conclusion, work with a computer mouse under time pressure and verbal provocation (stress conditions) led to increased physiological and psychological reactions compared to control conditions.
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Svensson J. Antenatal education classes in Victoria: what the women said. AUSTRALIAN JOURNAL OF MIDWIFERY : PROFESSIONAL JOURNAL OF THE AUSTRALIAN COLLEGE OF MIDWIVES INCORPORATED 2002; 14:15. [PMID: 11887647 DOI: 10.1016/s1445-4386(01)80006-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Svensson J, Johannsson G, Bengtsson BA. Body composition and quality of life as markers of the efficacy of growth hormone replacement therapy in adults. HORMONE RESEARCH 2002; 55 Suppl 2:55-60. [PMID: 11684878 DOI: 10.1159/000063476] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Growth hormone (GH) replacement therapy in GH-deficient adults should be initiated with a low dose, independent of body weight or body surface area. Measurements of serum insulin-like growth factor I (IGF-I) concentrations, as well as clinical examinations aimed at detecting signs of fluid excess, are important as safety markers to avoid overtreatment with GH. At present, there is no optimal marker for the long-term efficacy of GH replacement therapy. The long-term maintenance dose of GH should, therefore, be titrated in each individual based on the clinical response, with the aim of normalizing body hydration, other measurements of body composition, quality of life and well-being, and biochemical indices such as serum IGF-I concentration.
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Koranyi J, Svensson J, Götherström G, Sunnerhagen KS, Bengtsson B, Johannsson G. Baseline characteristics and the effects of five years of GH replacement therapy in adults with GH deficiency of childhood or adulthood onset: a comparative, prospective study. J Clin Endocrinol Metab 2001; 86:4693-9. [PMID: 11600527 DOI: 10.1210/jcem.86.10.7896] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The consequences of GH deficiency may differ if the disease is childhood onset or adulthood onset. In this single-center, prospective study, 21 consecutive adults with childhood onset GH deficiency and 21 adults with adulthood onset GH deficiency, matched for age, gender, body mass index, and number of anterior pituitary hormonal deficiencies, were included. Baseline differences and differences in the responses in body composition, muscle strength, bone mass, and metabolic indices during 5-yr GH replacement were determined. The duration of GH deficiency was longer and serum IGF-I level and body height were lower in the childhood onset patients than in the adulthood onset patients. Body fat (observed/predicted ratio) was increased, and lean mass and muscle strength were decreased, in the childhood onset patients. Total body and lumbar (L2-L4) bone mineral content and bone mineral density were lower in the childhood onset patients. Serum total cholesterol level was higher in the adulthood onset patients. The childhood onset and adulthood onset patients received a similar dose of GH. After adjustment for body weight, however, the dose of GH was higher in the childhood onset patients. The treatment responses were more marked in the childhood onset patients in lean mass, knee extensor strength, left-hand grip strength, and in total body and lumbar (L2-L4) bone mineral content and bone mineral density. The reduction in serum total cholesterol concentration was more marked in the adulthood onset patients. At study end, no differences remained between the two study groups after the correction for body height in the statistical analysis. In conclusion, the baseline analysis suggests more decreased lean mass, muscle strength, and bone mass in the childhood onset patients whereas the lipid profile was more disturbed in the adulthood onset patients. The 5-yr GH replacement eliminated all the anthropodometric and metabolic differences between the two groups.
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Götherström G, Svensson J, Koranyi J, Alpsten M, Bosaeus I, Bengtsson B, Johannsson G. A prospective study of 5 years of GH replacement therapy in GH-deficient adults: sustained effects on body composition, bone mass, and metabolic indices. J Clin Endocrinol Metab 2001; 86:4657-65. [PMID: 11600522 DOI: 10.1210/jcem.86.10.7887] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
GH replacement therapy has proved its efficacy and safety in short-term trials and in a few long-term trials with limited number of subjects. In this 1-center study, including 118 consecutive adults (70 men and 48 women; mean age, 49.3 yr; range, 22-74 yr) with adult-onset GH deficiency, the effects of 5 yr of GH replacement on body composition, bone mass, and metabolic indices were determined. The mean initial GH dose was 0.98 mg/d. The dose was gradually lowered, and after 5 yr the mean dose was 0.48 mg/d. The mean IGF-I SD score increased from -1.73 at baseline to 1.66 at study end. A sustained increase in lean body mass and a decrease in body fat were observed. The GH treatment increased total body bone mineral content as well as lumbar (L2-L4) and femur neck bone mineral contents. BMD in lumbar spine (L2-L4) and femur neck were increased and normalized at study end. Total cholesterol and low density lipoprotein cholesterol decreased, and high density lipoprotein cholesterol increased. At 5 yr, serum concentrations of triglycerides and hemoglobin A(1c) were reduced compared with baseline values. The treatment responses in IGF-I SD score, body fat as estimated by four- and five-compartment body composition models, total body protein and nitrogen, and lumbar bone mineral content and BMD were more marked in men than in women. One patient died during the period, four patients discontinued the study due to adverse events, and one dropped out due to lack of compliance. Four patients were lost to follow-up. However, all patients were retained in the statistical analysis according to the intention to treat approach used. In conclusion, 5 yr of GH substitution in GH-deficient adults is safe and well tolerated. The effects on body composition, bone mass, and metabolic indices were sustained. The effects on body composition and low density lipoprotein cholesterol were seen after 1 yr, whereas the effects on bone mass, triglycerides, and hemoglobin A(1c) were first observed after years of treatment.
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Codner E, Cassorla F, Tiulpakov AN, Mericq MV, Avila A, Pescovitz OH, Svensson J, Cerchio K, Krupa D, Gertz BJ, Murphy G. Effects of oral administration of ibutamoren mesylate, a nonpeptide growth hormone secretagogue, on the growth hormone-insulin-like growth factor I axis in growth hormone-deficient children. Clin Pharmacol Ther 2001; 70:91-8. [PMID: 11452249 DOI: 10.1067/mcp.2001.116514] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ibutamoren mesylate (MK-0677), an orally active nonpeptide growth hormone (GH) secretagogue, stimulates GH release through a pituitary and hypothalamic receptor that is different from the GH-releasing hormone receptor. We evaluated the safety and tolerability and the GH-insulin-like growth factor (IGF) responses to two dosages of oral ibutamoren mesylate given to children with GH deficiency for 7 to 8 days. The patients, 18 prepubertal children (15 male, 3 female) with idiopathic GH deficiency, had a chronologic age of 10.6 +/- 0.8 years (mean +/- SD), bone age of 7.4 +/- 0.7 years, growth velocity < 10th percentile for age, height < 10th percentile for age, and a maximum GH response of < or = 10 microg/L to two different GH stimulation tests. The children were assigned as follows to one of three treatment groups with ibutamoren mesylate: 0.2 mg/kg per day for 7 days (days 1-7 or 8-14) and matching placebo for the alternate 7 days (groups I and II, respectively) or 0.8 mg/kg per day for 7 days (days 8-14, group III). On day 15 all patients received an 0.8-mg/kg dose of ibutamoren mesylate. Patients in groups I and II were studied first to assess safety at the low dose before advancement to the high dose. Hormonal profiles were evaluated on day -1 (baseline) and day 15, and the results were expressed as the change from baseline within each group. After administration of ibutamoren mesylate 0.8 mg/kg for 8 days (group III), the median increases (on day 15) from baseline were as follows: 3.8 microg/L (range, 0 to 34.3) for serum GH peak concentration (P = .001), 4.3 microg x h/L (range, 1.3 to 35.6) for the GH area under the concentration-time curve from time zero to 8 hours (AUC(0-8)) (P < .001), 12 microg/L (range, -4 to 116) for serum IGF-I (P = .01), and 0.4 microg/L (range, -0.9 to 1.5) for serum IGF-binding protein 3 (IGFBP-3) (P = .01). There was no change in serum prolactin, glucose, triiodothyronine, thyroxine, thyrotropin, peak serum cortisol, and insulin concentrations or 24-hour urinary free cortisol after administration of 0.8 mg/kg per day of ibutamoren mesylate for 8 days. We conclude that short-term administration of ibutamoren mesylate can increase GH, IGF-I, and IGFBP-3 levels in some children with GH deficiency. Thus this compound is applicable for testing its effect on growth velocity.
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Hedström M, Sjöberg K, Svensson J, Brosjö E, Dalén N. Changes in biochemical markers of bone metabolism and BMD during the first year after a hip fracture. ACTA ORTHOPAEDICA SCANDINAVICA 2001; 72:248-51. [PMID: 11480599 DOI: 10.1080/00016470152846565] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
We measured the levels of biochemical markers of bone formation and bone resorption in hip fracture patients preoperatively and after 6 and 12 months. Bone densitometry was done with quantitative computer tomography (QCT), dual-energy X-ray absorptiometry (DXA) and heel ultrasound. After 6 months, the biochemical markers of bone formation and bone resorption had increased. The levels remained high after 1 year and no change occurred between 6 and 12 months. We found no correlations between biochemical bone markers and bone density/stiffness on admission and change in bone mineral density (BMD) during the first postoperative year, despite the changes in bone markers and bone density. In our opinion, biochemical bone markers can not be used to predict bone loss in the individual patient after a hip fracture.
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