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  • 1.
    Aare, Kätlin
    et al.
    Stockholms universitet, Humanistiska fakulteten, Institutionen för lingvistik. University of Tartu, Estonia.
    Włodarczak, Marcin
    Stockholms universitet, Humanistiska fakulteten, Institutionen för lingvistik.
    Heldner, Mattias
    Stockholms universitet, Humanistiska fakulteten, Institutionen för lingvistik.
    Breath holds in spontaneous speech2019Inngår i: Eesti ja soome-ugri keeleteaduse ajakiri, ISSN 1736-8987, E-ISSN 2228-1339, Vol. 10, nr 1, s. 13-34Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article provides a first quantitative overview of the timing and volume-related properties of breath holds in spontaneous conversations. Firstly, we investigate breath holds based on their position within the coinciding respiratory interval amplitude. Secondly, we investigate breath holds based on their timing within the respiratory intervals and in relation to communicative activity following breath holds. We hypothesise that breath holds occur in different regions of the lung capacity range and at different times during the respiratory phase, depending on the conversational and physiological activity following breath holds. The results suggest there is not only considerable variation in both the time and lung capacity scales, but detectable differences are also present in breath holding characteristics involving laughter and speech preparation, while breath holds coinciding with swallowing are difficult to separate from the rest of the data based on temporal and volume information alone.

  • 2.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Blind, Per Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Kirurgi.
    Outcome of microdialysis sampling on liver surface and parenchyma2016Inngår i: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 200, nr 2, s. 480-487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: To investigate whether surface microdialysis (μD) sampling in probes covered by a plastic film, as compared to noncovered and to intraparenchymatous probes, would increase the technique's sensitivity for pathophysiologic events occurring in a liver ischemia-reperfusion model. Placement of μD probes in the parenchyma of an organ, as is conventionally done, may cause adverse effects, e.g., bleeding, possibly influencing outcome.

    Methods: A transient ischemia-reperfusion model of the liver was used in six anesthetized normoventilated pigs. μD probes were placed in the parenchyma and on the liver surface. Surface probes were either left uncovered or were covered by plastic film.

    Results: Lactate and glucose levels were significantly higher in plastic film covered probes than in uncovered surface probes throughout the ischemic period. Glycerol levels were significantly higher in plastic film covered probes than in uncovered surface probes at 30 and 45 min into ischemia.

    Conclusions: Covering the μD probe increases the sensibility of the μD–technique in monitoring an ischemic insult and reperfusion in the liver. These findings confirm that the principle of surface μD works, possibly replacing need of intraparenchymatous placement of μD probes. Surface μD seemingly allows, noninvasively from an organ's surface, via the extracellular compartment, assessment of intracellular metabolic events. The finding that covered surface μD probes allows detection of local metabolic changes earlier than do intraparenchymatous probes, merit further investigation focusing on μD probe design.

  • 3.
    Abrahamsson, Pernilla
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Åberg, Anna-Maja
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Johansson, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Winsö, Ola
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Waldenström, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Haney, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Anestesiologi och intensivvård.
    Detection of myocardial ischaemia using surface microdialysis on the beating heart2011Inngår i: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 31, nr 3, s. 175-181Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Microdialysis (MD) can be used to study metabolism of the beating heart. We investigated whether microdialysis results obtained from epicardial (surface) sampling reflect acute changes in the same way as myocardial sampling from within the substance of the ventricular wall. In anaesthetized open-thorax pigs a coronary snare was placed. One microdialysis probe was placed with the sampling membrane intramyocardially (myocardial), and a second probe was placed with the sampling membrane epicardially (surface), both in the area which was made ischaemic. Ten minutes collection intervals were used for microdialysis samples. Samples from 19 pigs were analysed for lactate, glucose, pyruvate and glycerol during equilibration, baseline, ischaemia and reperfusion periods. For both probes (surface and myocardial), a total of 475 paired simultaneous samples were analysed. Results from analyses showed no differences in relative changes for glucose, lactate and glycerol during baseline, ischaemia and reperfusion. Surface microdialysis sampling is a new application of the microdialysis technique that shows promise and should be further studied.

    Fulltekst (pdf)
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  • 4.
    Abreu-Vieira, Gustavo
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för molekylär biovetenskap, Wenner-Grens institut.
    Thermal physiology and metabolism: Interplay between heat generation and energy homeostasis2015Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Mammal metabolism is intimately connected to the maintenance of body temperature. While metabolic pathways invariably produce heat as a by-product, the natural heat present in the environment also plays a role in defining the adaptive metabolism and general physiology of an organism. This thesis aims to discuss basic aspects of energy expenditure and their interactions with energy stores and body composition. In Paper I, we apply a new technique – high-resolution laser-Doppler imaging – to describe physiological regulatory features of adrenergically-stimulated blood flow in brown adipose tissue, and evaluate the validity of blood flow as a parameter to estimate nonshivering thermogenesis. Paper II focuses on the central regulation of body temperature. In the absence of bombesin receptor subtype-3, mice present an altered neurological body temperature setpoint, while peripheral thermogenic capacity remains intact. We conclude that brown adipose tissue malfunction is not the cause of the hypothermia observed in this mouse model. Paper III incorporates measurements of body temperature to the energy expenditure of different sources: basal metabolic rate, physical activity, thermic effect of food, and cold-induced thermogenesis. We describe basic aspects of dynamic insulation, energetic costs of circadian variation and hypothesize that physical activity may change the body temperature setpoint. Paper IV describes methodological issues related to glucose tolerance tests in obese mice. We conclude that the erroneous scaling of doses may affect the interpretation of metabolic health in mouse models, and suggest a new methodology. Paper V describes the outcomes caused by the expression of the human Cidea protein in adipose tissue of mice and suggests that this protein may clarify the link between adipose tissue expansion and healthy obesity. Paper VI explores the dissociation between thiazolidinedione-induced adipose tissue “browning” and reduced blood glycaemia. We demonstrate that although this pharmacological class tends to induce some level of brown adipose tissue recruitment, this phenomenon does not define its antidiabetic effects.

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  • 5.
    Addinsall, Alex B.
    et al.
    Department of Physiology and PharmacologyKarolinska InstituteStockholm.
    Cacciani, Nicola
    Department of Physiology and PharmacologyKarolinska InstituteStockholm;Department of Clinical NeuroscienceKarolinska InstituteStockholm.
    Akkad, Hasem
    Department of Physiology and PharmacologyKarolinska InstituteStockholm.
    Moruzzi, Noah
    Department of Molecular Medicine and SurgeryKarolinska InstituteStockholm.
    Maestri, Alice
    Department of MedicineKarolinska InstituteStockholm.
    Shevchenko, Ganna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Ruas, Jorge
    Department of Physiology and PharmacologyKarolinska InstituteStockholm.
    Larsson, Lars
    Department of Physiology and PharmacologyKarolinska InstituteStockholm;Viron Molecular Medicine InstituteBostonMA.
    Ruxolitinib Prevents Ventilator Induced Diaphragm Dysfunction2022Inngår i: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 36, nr S1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mechanical ventilation (MV), however brief results in the loss of diaphragm muscle mass and strength, termed ventilator induced diaphragm dysfunction (VIDD). VIDD increases dependence, complicates and prolongs weaning and significantly increases discharge mortality rate and health care costs worldwide. The Janus kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway was recently identified as an important signalling pathway implicated in VIDD, upregulated in the diaphragm following MV and limb muslces during critical care. Regulation of STAT3 is imperritve to skeletal muscle mass and function, as STAT3 is required in proper muscle growth and regeneration, while chronic activation of STAT3 is implicated in muscle dysfunction. As JAK/STAT pathway inhibition can restrict the development of chronic muscle wasting conditons, this study aimed to explore the therapeutic potential of Ruxolitinib, an approved JAK1/2 inhibitor for myelofibrosis, for treatment of CIM. We hypothesised Ruxolitinib would reduce loss of muscle mass and function associated with VIDD. Here, rats were subjected to five days controlled MV (CMV) with and without daily Ruxolitinib gavage. Five-days CMV significantly reduced diaphragm muscle size and impaired specific force, which was associated with 2-fold upregulation of P-STAT3, disrupted mitochondrial structure and respiratory function. Expression of the motor protein myosin was not affected, however CMV may alter myosin function through deamidation post translational modification. Ruxolitinib increases five-day survival rate, restored P-STAT3 expression and preserved diaphragm muscle size and specific force. These functional improvements were associated with improved mitochondrial structure, augmented mitochondrial respiratory function and reversal or augmentation of myosin deamidations. These results provide evidence of the preclinical potential of repurposing Ruxolitinib for the treatment of VIDD.

  • 6.
    Addinsall, Alex B.
    et al.
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden..
    Cacciani, Nicola
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden.;Karolinska Inst, Dept Clin Neurosci, Solna, Sweden..
    Backeus, Anders
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden..
    Hedstrom, Yvette
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden..
    Shevchenko, Ganna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Larsson, Lars
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden.;Karolinska Inst, Dept Clin Neurosci, Solna, Sweden.;Viron Mol Med Inst Boston, Boston, MA USA..
    Electrical stimulated GLUT4 signalling attenuates critical illness-associated muscle wasting2022Inngår i: Journal of Cachexia, Sarcopenia and Muscle, ISSN 2190-5991, E-ISSN 2190-6009, Vol. 13, nr 4, s. 2162-2174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background Critical illness myopathy (CIM) is a debilitating condition characterized by the preferential loss of the motor protein myosin. CIM is a by-product of critical care, attributed to impaired recovery, long-term complications, and mortality. CIM pathophysiology is complex, heterogeneous and remains incompletely understood; however, loss of mechanical stimuli contributes to critical illness-associated muscle atrophy and weakness. Passive mechanical loading and electrical stimulation (ES) therapies augment muscle mass and function. While having beneficial outcomes, the mechanistic underpinning of these therapies is less known. Therefore, here we aimed to assess the mechanism by which chronic supramaximal ES ameliorates CIM in a unique experimental rat model of critical care. Methods Rats were subjected to 8 days of critical care conditions entailing deep sedation, controlled mechanical ventilation, and immobilization with and without direct soleus ES. Muscle size and function were assessed at the single cell level. RNAseq and western blotting were employed to understand the mechanisms driving ES muscle outcomes in CIM. Results Following 8 days of controlled mechanical ventilation and immobilization, soleus muscle mass, myosin : actin ratio, and single muscle fibre maximum force normalized to cross-sectional area (CSA; specific force) were reduced by 40-50% (P < 0.0001). ES significantly reduced the loss of soleus muscle fibre CSA and myosin : actin ratio by approximately 30% (P < 0.05) yet failed to effect specific force. RNAseq pathway analysis revealed downregulation of insulin signalling in the soleus muscle following critical care, and GLUT4 trafficking was reduced by 55% leading to an 85% reduction of muscle glycogen content (P < 0.01). ES promoted phosphofructokinase and insulin signalling pathways to control levels (P < 0.05), consistent with the maintenance of GLUT4 translocation and glycogen levels. AMPK, but not AKT, signalling pathway was stimulated following ES, where the downstream target TBC1D4 increased 3 logFC (P = 0.029) and AMPK-specific P-TBC1D4 levels were increased approximately two-fold (P = 0.06). Reduction of muscle protein degradation rather than increased synthesis promoted soleus CSA, as ES reduced E3 ubiquitin proteins, Atrogin-1 (P = 0.006) and MuRF1 (P = 0.08) by approximately 50%, downstream of AMPK-FoxO3. Conclusions ES maintained GLUT4 translocation through increased AMPK-TBC1D4 signalling leading to improved muscle glucose homeostasis. Soleus CSA and myosin content was promoted through reduced protein degradation via AMPK-FoxO3 E3 ligases, Atrogin-1 and MuRF1. These results demonstrate chronic supramaximal ES reduces critical care associated muscle wasting, preserved glucose signalling, and reduced muscle protein degradation in CIM.

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  • 7.
    Addinsall, Alex B.
    et al.
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol, Stockholm, Sweden.;Univ Copenhagen, Novo Nord Fdn Ctr Basic Metab Res, Copenhagen, Denmark..
    Cacciani, Nicola
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol, Stockholm, Sweden.;Karolinska Inst, Ctr Mol Med, Stockholm, Sweden..
    Moruzzi, Noah
    Karolinska Inst, Rolf Luft Res Ctr Diabet & Endocrinol, Dept Mol Med & Surg, Stockholm, Sweden..
    Akkad, Hazem
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol, Stockholm, Sweden..
    Maestri, Alice
    Karolinska Inst, Ctr Mol Med, Stockholm, Sweden.;Karolinska Inst, Dept Med, Div Cardiovasc Med, Solna, Sweden..
    Berggren, Per-Olof
    Karolinska Inst, Rolf Luft Res Ctr Diabet & Endocrinol, Dept Mol Med & Surg, Stockholm, Sweden..
    Widgren, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Bergquist, Jonas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Analytisk kemi.
    Tchkonia, Tamara
    Viron Mol Med Inst, Muscle Biol Program, Boston, MA USA..
    Kirkland, James L.
    Mayo Clin, Dept Physiol & Biomed Engn, Rochester, MN USA.;Mayo Clin, Div Gen Internal Med, Rochester, MN USA..
    Larsson, Lars
    Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol, Stockholm, Sweden.;Karolinska Inst, Ctr Mol Med, Stockholm, Sweden.;Viron Mol Med Inst, Muscle Biol Program, Boston, MA USA.;Karolinska Inst, Dept Physiol & Pharmacol, Basic & Clin Muscle Biol Grp, Solnavagen 9, S-17165 Solna, Sweden..
    Ruxolitinib: A new hope for ventilator-induced diaphragm dysfunction2024Inngår i: Acta Physiologica, ISSN 1748-1708, E-ISSN 1748-1716, Vol. 240, nr 5Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: Mechanical ventilation (MV) results in diminished diaphragm size and strength, termed ventilator-induced diaphragm dysfunction (VIDD). VID increases dependence, prolongs weaning, and increases discharge mortality rates. The Janus kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway is implicated in VIDD, upregulated following MV. JAK/STAT inhibition alleviates chronic muscle wasting conditions. This study aimed to explore the therapeutic potential of Ruxolitinib, an FDA approved JAK1/2 inhibitor (JI) for the treatment of VIDD. Methods: Rats were subjected to 5 days controlled MV (CMV) with and without daily Ruxolitinib gavage. Muscle fiber size and function were assessed. RNAseq, mitochondrial morphology, respirometry, and mass spectrometry were determined. Results: CMV significantly reduced diaphragm size and specific force by 45% (p < 0.01), associated with a two-fold P-STAT3 upregulation (p < 0.001). CMV disrupted mitochondrial content and reduced the oxygen consumption rate (p < 0.01). Expression of the motor protein myosin was unaffected, however CMV alters myosin function via post-translational modifications (PTMs). Daily administration of JI increased animal survival (40% vs. 87%; p < 0.05), restricted P-STAT3 (p < 0.001), and preserved diaphragm size and specific force. JI was associated with preserved mitochondrial content and respiratory function (p < 0.01), and the reversal or augmentation of myosin deamidation PTMs of the rod and head region. Conclusion: JI preserved diaphragm function, leading to increased survival in an experimental model of VIDD. Functional enhancement was associated with maintenance of mitochondrial content and respiration and the reversal of ventilator-induced PTMs of myosin. These results demonstrate the potential of repurposing Ruxolitinib for treatment of VIDD.

    Fulltekst (pdf)
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  • 8. Adiels, Martin
    et al.
    Mardinoglu, Adil
    KTH, Skolan för bioteknologi (BIO), Proteomik och nanobioteknologi. KTH, Centra, Science for Life Laboratory, SciLifeLab. Chalmers University of Technology, Sweden.
    Taskinen, Marja-Riitta
    Boren, Jan
    Kinetic Studies to Elucidate Impaired Metabolism of Triglyceride-rich Lipoproteins in Humans2015Inngår i: Frontiers in Physiology, E-ISSN 1664-042X, Vol. 6, artikkel-id 342Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    To develop novel strategies for prevention and treatment of dyslipidemia, it is essential to understand the pathophysiology of dyslipoproteinemia in humans. Lipoprotein metabolism is a complex system in which abnormal concentrations of various lipoprotein particles can result from alterations in their rates of production, conversion, and/or catabolism. Traditional methods that measure plasma lipoprotein concentrations only provide static estimates of lipoprotein metabolism and hence limited mechanistic information. By contrast, the use of tracers labeled with stable isotopes and mathematical modeling, provides us with a powerful tool for probing lipid and lipoprotein kinetics in vivo and furthering our understanding of the pathogenesis of dyslipoproteinemia.

  • 9.
    Adolfsson, Peter
    et al.
    Institute of Clinical Sciences, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden; Endocrine and Diabetes Center, The hospital of Halland Kungsbacka, Kungsbacka, Sweden.
    Mattsson, Stig
    Faculty of Health Sciences and Medicine, Örebro University Hospital, Örebro, Sweden; Endocrine and Diabetes Center, Falun Hospital, Falun, Sweden.
    Jendle, Johan
    Faculty of Health Sciences and Medicine, Örebro University Hospital, Örebro, Sweden; Endocrine and Diabetes Center, Karlstad Hospital, Karlstad, Sweden.
    Evaluation of glucose control when a new strategy of increased carbohydrate supply is implemented during prolonged physical exercise in type 1 diabetes2015Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 115, nr 12, s. 2599-2607Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: In healthy individuals, high carbohydrate intake is recommended during prolonged exercise for maximum performance. In type 1 diabetes (T1D), this would alter the insulin requirements. The aim of the study was to evaluate the safety of high glucose supplementation during prolonged exercise and the glucose control when a novel strategy of increased carbohydrate supply was implemented during prolonged exercise in T1D.

    Methods: Eight subjects with T1D participated in a sports camp including sessions of prolonged exercise and individualized feedback during three consecutive days. This was later followed by a 90 km cross-country skiing race. Large amounts of carbohydrates, 75 g/h, were supplied during exercise and the insulin requirements were registered. Glucose was measured before, during and after exercise aiming at euglycaemia, 4-8 mmol/L (72-144 mg/dL). During the race, continuous glucose monitoring (CGM) was used as an aspect of safety and to allow direct and individual adjustments.

    Results: Compared to ordinary carbohydrate supply during exercise, the high carbohydrate supplementation resulted in significantly increased insulin doses to maintain euglycaemia. During the cross-country skiing race, the participants succeeded to reach mean target glucose levels; 6.5 ± 1.9 mmol/L (117 ± 34 mg/dL) and 5.7 ± 1.5 mmol/L (103 ± 27 mg/dL) at the start and finish of the race, respectively. Episodes of documented hypoglycemia (<4 mmol/L/72 mg/dL) were rare. CGM was used for adjustments.

    Conclusion: In this study, large carbohydrate supplementation in T1D individuals during prolonged aerobic exercise is safe and allows the subjects to maintain glycaemic control and indicates the feasibility of CGM under these conditions.

  • 10.
    Aghanavesi, Somayeh
    et al.
    Computer Engineering, School of Technology and Business Studies, Borlänge, Dalarna University, Sweden.
    Bergquist, Filip
    Dept. of Pharmacology, University of Gothenburg, Gothenburg, Sweden.
    Nyholm, Dag
    Dept. of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Senek, Marina
    Dept. of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Memedi, Mevludin
    Örebro universitet, Handelshögskolan vid Örebro Universitet.
    Objective assessment of Parkinson’s disease motor symptoms during leg agility test using motion sensors2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Title: Objective assessment of Parkinson’s disease motor symptoms during leg agility test using motion sensors

    Objective: To develop and evaluate machine learning methods for assessment of Parkinson’s disease (PD) motor symptoms using leg agility (LA) data collected with motion sensors during a single dose experiment.

    Background: Nineteen advanced PD patients (Gender: 14 males and 5 females, mean age: 71.4, mean years with PD: 9.7, mean years with levodopa: 9.5) were recruited in a single center, open label, single dose clinical trial in Sweden [1].

    Methods: The patients performed up to 15 LA tasks while wearing motions sensors on their foot ankle. They performed tests at pre-defined time points starting from baseline, at the time they received a morning dose (150% of their levodopa equivalent morning dose), and at follow-up time points until the medication wore off. The patients were video recorded while performing the motor tasks. and three movement disorder experts rated the observed motor symptoms using 4 items from the Unified PD Rating Scale (UPDRS) motor section including UPDRS #26 (leg agility), UPDRS #27 (Arising from chair), UPDRS #29 (Gait), UPDRS #31 (Body Bradykinesia and Hypokinesia), and dyskinesia scale. In addition, they rated the overall mobility of the patients using Treatment Response Scale (TRS), ranging from -3 (very off) to 3 (very dyskinetic). Sensors data were processed and their quantitative measures were used to develop machine learning methods, which mapped them to the mean ratings of the three raters. The quality of measurements of the machine learning methods was assessed by convergence validity, test-retest reliability and sensitivity to treatment.

    Results: Results from the 10-fold cross validation showed good convergent validity of the machine learning methods (Support Vector Machines, SVM) with correlation coefficients of 0.81 for TRS, 0.78 for UPDRS #26, 0.69 for UPDRS #27, 0.78 for UPDRS #29, 0.83 for UPDRS #31, and 0.67 for dyskinesia scale (P<0.001). There were good correlations between scores produced by the methods during the first (baseline) and second tests with coefficients ranging from 0.58 to 0.96, indicating good test-retest reliability. The machine learning methods had lower sensitivity than mean clinical ratings (Figure. 1).

    Conclusions: The presented methodology was able to assess motor symptoms in PD well, comparable to movement disorder experts. The leg agility test did not reflect treatment related changes.

    Fulltekst (pdf)
    Objective assessment of Parkinson’s disease motor symptoms during leg agility test using motion sensors
  • 11.
    Aghanavesi, Somayeh
    et al.
    Computer Engineering, School of Technology and Business Studies, Dalarna University, Borlänge, Sweden.
    Filip, Bergquist
    Dept. of Pharmacology, University of Gothenburg, Gothenbrug, Sweden.
    Nyholm, Dag
    Dept. of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Senek, Marina
    Dept. of Neuroscience, Neurology, Uppsala University, Uppsala, Sweden.
    Memedi, Mevludin
    Örebro universitet, Handelshögskolan vid Örebro Universitet.
    Feasibility of a multi-sensor data fusion method for assessment of Parkinson’s disease motor symptoms2018Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Title: Feasibility of a multi-sensor data fusion method for assessment of Parkinson’s disease motor symptoms

    Objective: To assess the feasibility of measuring Parkinson’s disease (PD) motor symptoms with a multi-sensor data fusion method. More specifically, the aim is to assess validity, reliability and sensitivity to treatment of the methods.

    Background: Data from 19 advanced PD patients (Gender: 14 males and 5 females, mean age: 71.4, mean years with PD: 9.7, mean years with levodopa: 9.5) were collected in a single center, open label, single dose clinical trial in Sweden [1].

    Methods: The patients performed leg agility and 2-5 meter straight walking tests while wearing motion sensors on their limbs. They performed the tests at baseline, at the time they received the morning dose, and at pre-specified time points until the medication wore off. While performing the tests the patients were video recorded. The videos were observed by three movement disorder specialists who rated the symptoms using a treatment response scale (TRS), ranging from -3 (very off) to 3 (very dyskinetic). The sensor data consisted of lower limb data during leg agility, upper limb data during walking, and lower limb data during walking. Time series analysis was performed on the raw sensor data extracted from 17 patients to derive a set of quantitative measures, which were then used during machine learning to be mapped to mean ratings of the three raters on the TRS scale. Combinations of data were tested during the machine learning procedure.

    Results: Using data from both tests, the Support Vector Machines (SVM) could predict the motor states of the patients on the TRS scale with a good agreement in relation to the mean ratings of the three raters (correlation coefficient = 0.92, root mean square error = 0.42, p<0.001). Additionally, there was good test-retest reliability of the SVM scores during baseline and second tests with intraclass-correlation coefficient of 0.84. Sensitivity to treatment for SVM was good (Figure 1), indicating its ability to detect changes in motor symptoms. The upper limb data during walking was more informative than lower limb data during walking since SVMs had higher correlation coefficient to mean ratings.  

    Conclusions: The methodology demonstrates good validity, reliability, and sensitivity to treatment. This indicates that it could be useful for individualized optimization of treatments among PD patients, leading to an improvement in health-related quality of life.

    Fulltekst (pdf)
    Feasibility of a multi-sensor data fusion method for assessment of Parkinson’s disease motor symptoms
  • 12.
    Agvald, Per
    et al.
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Adding, L. Christofer
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Nilsson, Kristofer F.
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Gustafsson, Lars E.
    Centre for Allergy Research, Karolinska Institutet, Stockholm, Sweden.
    Linnarsson, Dag
    Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.
    Increased expired NO and roles of CO2 and endogenous NO after venous gas embolism in rabbits2006Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 97, nr 2, s. 210-215Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Venous gas embolism (VGE) is a feared complication in diving, aviation, surgery and trauma. We hypothesized that air emboli in the lung circulation might change expired nitric oxide (FeNO). A single intravenous infusion of air was given (100 mul kg(-1)) to three groups of anaesthetized mechanically ventilated rabbits: (A) one with intact NO production, (B) one with intact NO production and where end-tidal CO(2) was controlled, and (C) one with endogenous NO synthesis blockade (L: -NAME, 30 mg kg(-1)). Air infusions resulted in increased FeNO of the control group from 20 (4) [mean (SD)] ppb to a peak value of 39 (4) ppb within 5 min (P < 0.05), and FeNO was still significantly elevated [27 (2) ppb] after 20 min (P < 0.05). Parallel to the NO increase there were significant decreases in end-tidal CO(2 )(ETCO(2)) and mean arterial pressure and an increase in insufflation pressure. In group B, when CO(2) was supplemented after air infusion, NO was suppressed (P = 0.033), but was still significantly elevated compared with pre-infusion control (P < 0.05). In group C, all animals died within 40 min of air infusion whereas all animals in the other groups were still alive at this time point. We conclude that venous air embolization increases FeNO, and that a part of this effect is due to the concomitant decrease in ETCO(2). Furthermore, an intact NO production may be critical for the tolerance to VGE. Finally, FeNO might have a potential in the diagnosis and monitoring of pulmonary gas embolism.

  • 13.
    Ahlén, Caroline
    Uppsala universitet, Medicinska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk biokemi och mikrobiologi.
    Outcome of patients with severe aortic stenosis – A retrospective follow-up study2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Aortic stenosis is the most common valvular disease in the adult population. A significant aortic stenosis is a serious condition, and if a symptomatic patient is not operated on, it may in most cases cause death. We have examined how many aortic stenoses that were diagnosed during one year, and a follow-up of the patients was also performed. We found 77 patients with significant aortic stenosis with a mean age of 76±13 years. At the time of follow-up 30 (39%) patients, aged between 29-85 years, had been surgically treated with implantation of a valve prosthesis within 2-23 months after the initial examination. At this initial examination 14 of the 30 patients who later underwent surgery had no symptoms. A coronary bypass operation was also performed on seven patients. Postoperative complications were observed in six patients, but none of them was fatal. At the initial examinations there were 26 (34%) patients with a significant aortic stenosis and symptoms who were not treated surgically. The main reason why these patients were not operated was high age, unwillingness, or severe left ventricular dysfunction. This study indicates the importance of repeated clinical and echocardiograpic examinations in patients with aortic stenosis. Almost half of the patients, that later underwent surgery, had no symptoms at the initial examination, but later developed symptoms which made surgery necessary. In one third of the patients no surgery was performed in spite of clinical symptoms.

    Fulltekst (pdf)
    FULLTEXT01
  • 14.
    Ahokas, E. K.
    et al.
    University of Jyväskylä.
    Kyröläinen, H.
    University of Jyväskylä.
    Mero, A. A.
    University of Jyväskylä.
    Walker, S.
    University of Jyväskylä.
    Hanstock, Helen
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Ihalainen, Johanna K.
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap. University of Jyväskylä.
    Water immersion methods do not alter muscle damage and inflammation biomarkers after high-intensity sprinting and jumping exercise2020Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 120, s. 2625-2634Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: The aim of this study was to compare the efficacy of three water immersion interventions performed after active recovery compared to active recovery only on the resolution of inflammation and markers of muscle damage post-exercise. Methods: Nine physically active men (n = 9; age 20‒35 years) performed an intensive loading protocol, including maximal jumps and sprinting on four occasions. After each trial, one of three recovery interventions (10 min duration) was used in a random order: cold-water immersion (CWI, 10 °C), thermoneutral water immersion (TWI, 24 °C), contrast water therapy (CWT, alternately 10 °C and 38 °C). All of these methods were performed after an active recovery (10 min bicycle ergometer), and were compared to active recovery only (ACT). 5 min, 1, 24, 48, and 96 h after exercise bouts, immune response and recovery were assessed through leukocyte subsets, monocyte chemoattractant protein-1, myoglobin and high-sensitivity C-reactive protein concentrations. Results: Significant changes in all blood markers occurred at post-loading (p < 0.05), but there were no significant differences observed in the recovery between methods. However, retrospective analysis revealed significant trial-order effects for myoglobin and neutrophils (p < 0.01). Only lymphocytes displayed satisfactory reliability in the exercise response, with intraclass correlation coefficient > 0.5. Conclusions: The recovery methods did not affect the resolution of inflammatory and immune responses after high-intensity sprinting and jumping exercise. It is notable that the biomarker responses were variable within individuals. Thus, the lack of differences between recovery methods may have been influenced by the reliability of exercise-induced biomarker responses. 

    Fulltekst (pdf)
    fulltext
  • 15.
    Ainegren, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling.
    Roller skis' rolling resistance and grip characteristics: influences on physiological and performance measures in cross-country skiers2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.

    Fulltekst (pdf)
    Doctoral thesis 125
  • 16.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Laaksonen, Marko S.
    Mittuniversitetet, Fakulteten för humanvetenskap, Avdelningen för hälsovetenskap.
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    The influence of grip on oxygen consumption and leg forces when using classical style roller skis2014Inngår i: Scandinavian Journal of Medicine and Science in Sports, ISSN 0905-7188, E-ISSN 1600-0838, Vol. 24, nr 2, s. 301-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to investigate the influence of classical style roller skis' grip (static friction coefficients, μ S) on cross-country skiers' oxygen consumption and leg forces during treadmill roller skiing, when using the diagonal stride and kick double poling techniques. The study used ratcheted wheel roller skis from the open market and a uniquely designed roller ski with an adjustable camber and grip function. The results showed significantly (P≤0.05) higher oxygen consumption (∼14%), heart rate (∼7%), and lower propulsive forces from the legs during submaximal exercise and a shorter time to exhaustion (∼30%) in incremental maximal tests when using roller skis with a μ S similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a similar, higher μ S. Thus, we concluded that oxygen consumption (skiing economy), propulsive leg forces, and performance time are highly changed for the worse when using roller skis with a lower μ S, such as for on-snow skiing with grip-waxed cross-country skis, in comparison to ratcheted wheel roller skis with several times higher μ S.

  • 17.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    An experimental study to compare the grip of classical style roller skis with on-snow skiing2013Inngår i: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 16, nr 2, s. 115-122Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cross-country skiers use roller skis for their snow-free training with the aim of imitating skiing on snow. Also, exercise laboratories evaluate the biomechanics and physiology of cross-country skiing using roller skis on a treadmill. The roller skis on the market that are constructed for use in the classical style are equipped with a front and a back wheel, one of which has a ratchet to enable it to grip the surface when diagonal striding and kick double poling (static friction). The aim of this study was to investigate static friction coefficients (μS) of ratcheted wheel roller skis, and compare the results to the μS reported from skiing on snow with grip-waxed cross-country skis. Also, a new type of roller ski with a camber and adjustable grip function was evaluated. The results showed that ratcheted wheel roller skis, on a treadmill rubber mat and on dry and wet asphalt surfaces, reached μS values that were five to eight times greater than the values reported from on-snow skiing with grip-waxed cross-country skis. For the roller skis with a camber and adjustable grip function, the μs could be varied from no grip at all up to the level of the tested ratcheted wheel roller skis.

  • 18.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013). Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap (-2013).
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Roller ski rolling resistance and its effects on elite athletes’ performance2009Inngår i: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 11, nr 3, s. 143-157Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes, the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study, the roller skis’ rolling resistance was measured on the ski-treadmill’s surface using a roller ski rolling resistance measurement system specially produced for this purpose. The study investigated the influence of significant changes in rolling resistance on physiological variables. The results showed that during submaximal exercise, power, oxygen uptake, heart rate and blood lactate were significantly changed by different rolling resistances, while there were no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed by different rolling resistances and this occurred without significant changes in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion were insignificant or small.

     

  • 19.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013). Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap (-2013).
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Roller ski rolling resistance and its effects on elite athletes’ performance2008Inngår i: ENGINEERING OF SPORT 7, VOL 2, 2008, Vol. 11, nr 3, s. 393-400Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Modern ski-treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical fitness in a laboratory environment whilst performing classical and freestyle (skating) techniques on roller skis. For elite athletes the differences in performance between test occasions are quite small, thus emphasising the importance of knowing the roller skis’ rolling resistance in order to allow the correct comparison between the results of different test occasions. In this study the roller skis’ rolling resistance has been measured using equipment on the ski-treadmill. The study investigates the influence of significant changes in rolling resistance on physiological variables. The results show that during submaximal exercise, heart rate, blood lactate, power and oxygen uptake are significantly changed by different rolling resistances, while there are no significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests show that time to exhaustion is significantly changed by different rolling resistances and this occurred without significant changes in maximal oxygen uptake and heart rate, and the influence on maximal power and ratings of perceived exertion were insignificant or small.

  • 20.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013). Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap (-2013).
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik och hållbar utveckling (-2013).
    Rolling resistance for treadmill roller skiing2008Inngår i: Sports Engineering, ISSN 1369-7072, E-ISSN 1460-2687, Vol. 11, nr 1, s. 23-29Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Modern treadmills allow cross-country skiers, biathletes and ski-orienteers to test their physical performance under laboratory conditions using classical and freestyle techniques on roller skis. The differences in performance between tests are quite small for elite athletes, and it is therefore of great importance to control the rolling resistance of the roller skis. Otherwise different physiological tests cannot be accurately compared.

    This study shows that during a warm-up period of  30 minutes the coefficient of rolling resistance (µR) decreases to about 60-65% and 70-75% of its initial value for freestyle and classical roller skis respectively.

    Simultaneous measurements of temperature and µR shows that stabilized rolling resistance corresponds to a certain running temperature for a given normal force on the roller ski.

    Tests were also performed on the influence on µR of normal force, velocity and inclination. Normal forces produced significant influence on µR , while different velocities and inclinations of the treadmill only resulted in small changes in µR.

  • 21.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik, fysik och matematik.
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Institutionen för teknik, fysik och matematik.
    Rolling resistance for treadmill roller skiing: Presented at International Congress on Science and Nordic Skiing 2006, June 18-20, 2006, Vuokatti, Finland2006Konferansepaper (Annet vitenskapelig)
  • 22.
    Ainegren, Mats
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Carlsson, Peter
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Tinnsten, Mats
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Laaksonen, Marko S.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kvalitetsteknik, maskinteknik och matematik.
    Skiing economy and efficiency in recreational and elite cross-country skiers2013Inngår i: Journal of Strength and Conditioning Research, ISSN 1064-8011, E-ISSN 1533-4287, Vol. 27, nr 5, s. 1239-1252Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to investigate and compare skiing economy and gross efficiency in cross-country skiers of different performance levels, ages and genders; male recreational skiers and elite senior and junior cross-country skiers of both genders. The skiers performed tests involving roller skiing on a treadmill using the gear 3 and diagonal stride techniques. The elite crosscountry skiers were found to have better skiing economy and higher gross efficiency (5-18%) compared with the recreational skiers (p < 0.05) and the senior elite had better economy and higher efficiency (4-5%) than their junior counterparts (p < 0.05), whereas no differences could be found between the genders. Also, large ranges in economy and gross efficiency were found in all groups. It was concluded that, in addition to v̇O2peak, skiing economy and gross efficiency have a great influence on the differences in performance times between recreational and junior and senior elite cross-country skiers, as well as between individual skiers within the different categories. Thus, we recommend crosscountry skiers at all performance levels to test not only v̇O2peak, but also skiing economy and efficiency.

  • 23.
    Ainegren, Mats
    et al.
    Sports Tech Research Centre, Department of Quality Management and Mechanical Engineering, Mid Sweden University, Östersund, Sweden.
    Hanstock, Helen
    Swedish Winter Sports Research Centre, Department of Health Sciences, Mid Sweden University, Östersund, Sweden.
    Stenfors, Nikolai
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Breathing resistance in heat and moisture exchanging devices2022Inngår i: Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, ISSN 1754-3371, Vol. 236, nr 2, s. 97-105Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The purpose of this study was to investigate the resistance to breathing (RES) in heat and moisture exchanging devices (HME) intended for use during physical activity in the cold. RES was investigated for seventeen HMEs, including different types of filters. In addition, the influence of headwind on RES was tested using four representative HMEs. HMEs were mounted to the face of an artificial head manufactured from ABS plastic. The HMEs were connected to a mechanical lung simulator, which delivered standardised inspiratory and expiratory air flow rates (V⋅, L/s). The delta pressure (Δp, Pa) between ambient air and the air inside the HME was measured, whereupon RES was calculated. The results showed significant (p < 0.05) differences in RES between HMEs from different manufacturers, while the difference was smaller, and in some cases not significant (p > 0.05), between different models/filters within the same brand. The results also showed that RES was highly influenced by different ventilations and headwind conditions. RES increased with increased V⋅ and, when a headwind was introduced, RES decreased during inspiration and increased during expiration. Calculations showed that the oxygen and energy cost for breathing through an HME was very small for most of the tested models. The effect of HME dead space on pulmonary gas fractions depends on the tidal volume. At large tidal volumes and ventilations, the effect of HMEs on pulmonary gas fractions becomes relatively small.

    Fulltekst (pdf)
    fulltext
  • 24.
    Akgül, Özge
    et al.
    Izmir Democracy Univ, Fac Arts & Sci, Dept Psychol, Izmir, Turkiye..
    Fide, Ezgi
    Dokuz Eylul Univ, Dept Neurosci, Izmir, Turkiye..
    Özel, Fatih
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för organismbiologi, Fysiologi och miljötoxikologi.
    Alptekin, Köksal
    Dokuz Eylul Univ, Dept Neurosci, Izmir, Turkiye.;Dokuz Eylul Univ, Fac Med, Dept Psychiat, Izmir, Turkiye..
    Bora, Emre
    Dokuz Eylul Univ, Dept Neurosci, Izmir, Turkiye.;Dokuz Eylul Univ, Fac Med, Dept Psychiat, Izmir, Turkiye..
    Akdede, Berna Binnur
    Dokuz Eylul Univ, Dept Neurosci, Izmir, Turkiye.;Dokuz Eylul Univ, Fac Med, Dept Psychiat, Izmir, Turkiye..
    Yener, Görsev
    Dokuz Eylul Univ, Brain Dynam Multidisciplinary Res Ctr, Izmir, Turkiye.;Izmir Univ Econ, Fac Med, Dept Neurol, Izmir, Turkiye.;Dokuz Eylul Univ, Izmir Int Biomed & Genome Inst, Izmir, Turkiye.;Izmir Univ Econ, Fac Med, Dept Neurol, TR-35340 Izmir, Turkiye..
    Enhanced Punishment Responses in Patients With Schizophrenia: An Event-Related Potential Study2024Inngår i: Clinical EEG and Neuroscience, ISSN 1550-0594, E-ISSN 2169-5202, Vol. 55, nr 2, s. 219-229Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is well known that abnormal reward processing is a characteristic feature of various psychopathologies including schizophrenia. Reduced reward anticipation has been suggested as a core symptom of schizophrenia. The Monetary Incentive Delay Task (MID) is frequently used to detect reward anticipation. The present study aims to evaluate the amplitude and latency of event-related potential (ERP) P300 in patients with schizophrenia (SCH) compared to healthy controls during the MID task. Twenty patients with SCH and 21 demographically matched healthy controls (HC) were included in the study. ERP P300 amplitude and latency values were compared between groups using an MID task in which reward and loss cues were presented. Relations between P300 and clinical facets were investigated in the patient group. SCH group had enhanced mean P300 amplitudes and delayed peak latency in the punishment condition compared with HC. These higher responses were also associated with negative symptoms. SCH group showed altered reward processing as being more sensitive to loss of reward conditions as firstly evidenced by electrophysiological methods, possibly due to abnormality in various systems including social withdrawal, social defeat, and behavioral inhibition system.

  • 25. Alfonso, Julieta
    et al.
    Pollevick, Guido
    Castensson, Anja
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Jazin, Elena
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för genetik och patologi.
    Frasch, Alberto
    Analysis of gene expression in the rat hippocampus using Real Time PCR reveals high inter-individual variation in mRNA expression levels2002Inngår i: Journal of Neuroscience Research, ISSN 0360-4012, E-ISSN 1097-4547, Vol. 67, nr 2, s. 225-34Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In mammals, gene transcription is a step subjected to tight regulation mechanisms. In fact, changes in mRNA levels in the central nervous system (CNS) can account for numerous phenotypic differences in brain function. We performed a high-resolution analysis of mRNA expression levels for 37 genes selected from a normal rat hippocampus cDNA library. mRNA amounts were quantified using a Real Time PCR SYBR Green assay. We found that, in general, individuals from an inbred rat population (n = 20) have shown 2-3 times differences in the basal level of expression of the genes analyzed. Up to several fold differences among individuals were observed for certain genes. These inter-individual differences were obtained after correction for the different amounts of mRNA in each sample. Power calculations were performed to determine the number of individuals required to detect reliable differences in expression levels between a control and an experimental group. These data indicated that, depending on the variability of the candidate gene selected, it was necessary to analyze from five to 135 individuals in each group to detect differences of 50% in the levels of mRNA expression between two groups investigated. The comparison of mRNA abundance from different genes revealed a wide range of expression levels for the 37 genes, showing a 26,000-fold difference between the highest and lowest expressed gene.

  • 26.
    Alfvén, G
    et al.
    Karolinska institutet.
    Grillner, S
    Karolinska institutet.
    Andersson, Eva
    Gymnastik- och idrottshögskolan, GIH, Institutionen för idrotts- och hälsovetenskap, Laboratoriet för biomekanik och motorisk kontroll (BMC). Karolinska institutet.
    Children with chronic stress-induced recurrent muscle pain have enhanced startle reaction.2017Inngår i: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 21, nr 9, s. 1561-1570Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Children with recurrent pain of negative chronic stress origin from different locations have a characteristic pattern of tender points in the temporal, trapezoid, great pectoral and abdominal muscles. We tested the hypothesis that the startle reaction is activated in these children and that some of the startle-activated muscles are related to the tender point pattern and the recurrent pain.

    METHODS: In children/adolescents, aged 10-17 years, 19 with recurrent psychosomatic pain (PAIN) and 23 controls (CON) we measured and analysed resting activity and acoustic startle response with electromyography (EMG) for the muscles involved in the pattern of tender points and also the lumbar erector spinae.

    RESULTS: The PAIN group showed higher resting activity and higher acoustic startle response values than the CON group for all six muscles together regarding the mean amplitude in the initial 200 ms, and during the burst of activity, and longer burst duration and shorter burst latency. For PAIN versus CON, all separate muscles showed generally higher values of EMG amplitudes and burst durations, and shorter latencies for the burst onset in all measures; with significance or strong trends for several parameters and muscles.

    CONCLUSION: For the first time in children with recurrent psychosomatic pain, increased resting activity and potentiated startle response were demonstrated in the muscles involved in the stress tender point pattern.

    SIGNIFICANCE: This study demonstrates in adolescents how recurrent pain of negative stress origin from the head, stomach, back and chest is related to increased startle reaction and increased muscular tension in these regions. This study contributes to the understanding of the mechanisms underlying the global burden of recurrent pain.

  • 27.
    Algotsson, Marcus
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Construct validity and test-retest reliability of a rotational maximum strength test and rotational power test in 1080 Quantum2016Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Explosive rotational movements are parts of many sports such as golf, tennis and baseball. Rotational strength and power tests exist, but valid and reliable tests to measure standing rotational strength and standing rotational power are lacking. 1080 Quantum is a machine wich can measure, speed, force and power and has several different resistance modes was used for testing rotational power and strength in this study. Aim: The aim was to investigate the validity and reliability of two new standing Quantum rotational tests; one measuring maximal rotational strength (1RM) and one measuring rotational power. Methods: Fifteen subjects, 8 men and 7 women, with at least one year of experience of resistance training participated in the study. The two new tests were: the Quantum power rotational test (PRT) and the Quantum 1RM rotational test (1RMRT). Testing occured during two sessions and during the first session construct validity of the two new rotational tests was assessed with a standing medicine ball throw (MB) and a sitting rotational power test (SRT). During the second session PRT and 1RMRT were tested for test-retest reliability. To study construct validity á priori hypothesis were stated and data were analyzed with Spearman´s correlation coefficent (rs). Intra correaltion coefficient (ICC) was used for test-retest reliability for PRT and 1RMRT. Results: Priori hypotheses were all fullfilled. Correlations found were considered good between PRT and MB (rs=0.80), moderate between PRT and SRT (rs=0.52), excellent between 1RMRT and MB (rs=0.90), moderate between 1RMRT and SRT (rs=0.73) and good between PRT and 1RMRT (rs=0.81). Excellent test-retest reliability was found for PRT (ICC=0.94, 95% CI (0.80-0.99)) and 1RMRT (ICC=0.98, 95% CI (0.92-0.99)) Conclusion: The two new rotational tests performed in 1080 Quantum both assessed construct validity and test-retest reliability. PRT can be used to measure standing rotational power and 1RMRT can be used to measure standing rotational maximum strength.

  • 28. Al-Harthy, Mohammad
    et al.
    Ekberg, EwaCarin
    Malmö högskola, Odontologiska fakulteten (OD).
    Nilner, Maria
    Malmö högskola, Odontologiska fakulteten (OD).
    Pain related temporomandibular disorders in adult Saudi arabians referred for specialized dental treatment2007Inngår i: Pain related temporomandibular disorders in adult Saudi arabians reffered for specialized dental treatment.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    The aim of the present study was to examine the frequencies of pain-related symptoms of TMD in patients in the age of 20-40 years referred for specialized dental treatments in Makkah, Saudi Arabia by using Research Diagnostic Criteria for TMD (RDC/TMD). Three hundred and twenty-five consecutive Saudi patients in the age of 20-40 years: 135 males and 190 females were interviewed according to the RDC/TMD history questionnaire. The results revealed that pain related TMD and orofacial pain were found among 58 (18%) patients. All other patients formed the non-pain group (267,82%). In the pain group, there were 79% females compared to 21% males (P<0.01). Both genders in the pain group reported high frequencies of both migraines in the last six months and headache moderately to extremely in the last month showing significant difference in comparison with the non-pain group (P<0.01). Symptoms of TMD were significantly more prevalent in the pain group than in the non-pain group. The most common pain related TMD symptoms were TMJ clicking, TMJ crepitation, TMJ locking, stiff jaw, tinnitus, bruxism and uncomfortable bite. Regarding Graded Chronic Pain severity in the pain group, most patients reported their pain to be grade I and II. Jaw disability checklist according to RDC/TMD showed that four or more disturbed jaw activities were found in 31 patients (53%) while 13 patients (22%) had not affected mandibular functions. In conclusion, the findings of the present study showed high frequencies of pain related TMD in this Saudi arabian patient population.

  • 29.
    Al-Husseini, Ali
    et al.
    Department of Clinical Sciences Lund, Neurosurgery, Skåne University Hospital, Lund University, Lund, Sweden.
    Gard, Anna
    Department of Clinical Sciences Lund, Neurosurgery, Skåne University Hospital, Lund University, Lund, Sweden.
    Fransson, Per-Anders
    Department of Clinical Sciences, Lund University, Lund, Sweden.
    Tegner, Yelverton
    Luleå tekniska universitet, Institutionen för hälsa, lärande och teknik, Hälsa, medicin och rehabilitering.
    Magnusson, Måns
    Department of Clinical Sciences, Lund University, Lund, Sweden.
    Marklund, Niklas
    Department of Clinical Sciences Lund, Neurosurgery, Skåne University Hospital, Lund University, Lund, Sweden.
    Tjernström, Fredrik
    Department of Clinical Sciences, Lund University, Lund, Sweden.
    Long-term postural control in elite athletes following mild traumatic brain injury2022Inngår i: Frontiers in Neurology, E-ISSN 1664-2295, Vol. 13, artikkel-id 906594Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Traumas to the head and neck are common in sports and often affects otherwise healthy young individuals. Sports-related concussions (SRC), defined as a mild traumatic brain injury (mTBI), may inflict persistent neck and shoulder pain, and headache, but also more complex symptoms, such as imbalance, dizziness, and visual disturbances. These more complex symptoms are difficult to identify with standard health care diagnostic procedures.

    Objective: To investigate postural control in a group of former elite athletes with persistent post-concussive symptoms (PPCS) at least 6 months after the incident.

    Method: Postural control was examined using posturography during quiet stance and randomized balance perturbations with eyes open and eyes closed. Randomized balance perturbations were used to examine motor learning through sensorimotor adaptation. Force platform recordings were converted to reflect the energy used to maintain balance and spectrally categorized into total energy used, energy used for smooth corrective changes of posture (i.e., <0.1 Hz), and energy used for fast corrective movements to maintain balance (i.e., >0.1 Hz).

    Results: The mTBI group included 20 (13 males, mean age 26.6 years) elite athletes with PPCS and the control group included 12 athletes (9 males, mean age 26.4 years) with no history of SRC. The mTBI group used significantly more energy during balance perturbations than controls: +143% total energy, p = 0.004; +122% low frequency energy, p = 0.007; and +162% high frequency energy, p = 0.004. The mTBI subjects also adapted less to the balance perturbations than controls in total (18% mTBI vs. 37% controls, p = 0.042), low frequency (24% mTBI vs. 42% controls, p = 0.046), and high frequency (6% mTBI vs. 28% controls, p = 0.040). The mTBI subjects used significantly more energy during quiet stance than controls: +128% total energy, p = 0.034; +136% low-frequency energy, p = 0.048; and +109% high-frequency energy, p = 0.015.

    Conclusion: Athletes with previous mTBI and PPCS used more energy to stand compared to controls during balance perturbations and quiet stance and had diminished sensorimotor adaptation. Sports-related concussions are able to affect postural control and motor learning.

  • 30.
    Ali, Hazrat
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Umander, Johannes
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Rohlén, Robin
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Grönlund, Christer
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    A Deep Learning Pipeline for Identification of Motor Units in Musculoskeletal Ultrasound2020Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 8, s. 170595-170608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Skeletal muscles are functionally regulated by populations of so-called motor units (MUs). An MU comprises a bundle of muscle fibers controlled by a neuron from the spinal cord. Current methods to diagnose neuromuscular diseases and monitor rehabilitation, and study sports sciences rely on recording and analyzing the bio-electric activity of the MUs. However, these methods provide information from a limited part of a muscle. Ultrasound imaging provides information from a large part of the muscle. It has recently been shown that ultrafast ultrasound imaging can be used to record and analyze the mechanical response of individual MUs using blind source separation. In this work, we present an alternative method - a deep learning pipeline - to identify active MUs in ultrasound image sequences, including segmentation of their territories and signal estimation of their mechanical responses (twitch train). We train and evaluate the model using simulated data mimicking the complex activation pattern of tens of activated MUs with overlapping territories and partially synchronized activation patterns. Using a slow fusion approach (based on 3D CNNs), we transform the spatiotemporal image sequence data to 2D representations and apply a deep neural network architecture for segmentation. Next, we employ a second deep neural network architecture for signal estimation. The results show that the proposed pipeline can effectively identify individual MUs, estimate their territories, and estimate their twitch train signal at low contraction forces. The framework can retain spatio-temporal consistencies and information of the mechanical response of MU activity even when the ultrasound image sequences are transformed into a 2D representation for compatibility with more traditional computer vision and image processing techniques. The proposed pipeline is potentially useful to identify simultaneously active MUs in whole muscles in ultrasound image sequences of voluntary skeletal muscle contractions at low force levels.

    Fulltekst (pdf)
    fulltext
  • 31. Alkner, B.
    et al.
    Norrbrand, Lena
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Tesch, P.
    Neuromuscular adaptations following 90 days bed rest with or without resistance exercise.2016Inngår i: Aerospace Medicine and Human Performance, ISSN 2375-6322, Vol. 87, nr 7, s. 610-617Artikkel i tidsskrift (Fagfellevurdert)
  • 32. Alkner, Björn A
    et al.
    Tesch, Per A
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Knee extensor and plantar flexor muscle size and function following 90 days of bed rest with or without resistance exercise.2004Inngår i: European Journal of Applied Physiology, ISSN 1439-6319, Vol. 93, nr 3, s. 294-305Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Skeletal muscle atrophy and strength loss induced by short-term simulated spaceflight are offset or attenuated by resistance exercise (RE). This study compared the effects of plantar flexor and knee extensor RE on muscle size and function in 17 healthy men (aged 26–41years) subjected to 90 days 6 head-down-tilt bed rest with (BRE; n=8) or without (BR; n=9) RE. The RE program consisted of coupled maximal concentric and eccentric actions in the supine squat (4 sets of 7 repetitions) and calf press (4·14) every third day employing a gravity-independent flywheel ergometer (FW). Prior to, and following bed rest, muscle volume was assessed using magnetic resonance imaging. Similarly, muscle strength and power and surface lectromyographic (EMG) activity were determined during maximal actions using FW or isokinetic dynamometry. In BR, knee extensor and plantar flexor muscle volume decreased (P<0.05) 18% and 29%, respectively. Torque or force and power decreased (P<0.05) 31–60% (knee extension) and 37–56% (plantar flexion) while knee extensor and plantar flexor EMG activity decreased 31–38% and 28–35%, respectively following BR. Muscle atrophy in BRE was prevented (P>0.05; knee extensors) or attenuated ()15%; plantar flexors). BRE maintained task-specific force, power and EMG activity. The decrease in non-task-specific torque was less (P<0.05) than in BR. The present data imply that the triceps surae and quadriceps muscles show different responsiveness to long-term bed rest with or without resistance exercise. The results also suggest that designing in-flight resistance exercise protocols for space travellers is complex and must extend beyond preserving

  • 33. Alkner, Björn
    et al.
    Jonsson, Lena
    Karolinska Institutet.
    Atling, Åsa
    Tesch, Per
    Resistance exercise maintains quadriceps muscle strength and size during 90 d bed rest.2003Inngår i: Medicine & Science in Sports & Exercise, ISSN 0195-9131, E-ISSN 1530-0315, Vol. 35, nr 5, s. 262-Artikkel i tidsskrift (Fagfellevurdert)
  • 34. Alkner, Björn
    et al.
    Norrbrand, Lena
    Karolinska Institutet.
    Tesch, Per
    Effects of 90 d bed rest with or without resistance exercise on knee extensor muscle fatigue2004Inngår i: 25th Annual International Gravitational Physiology Meeting, 2004Konferansepaper (Fagfellevurdert)
  • 35. Alkner, Björn
    et al.
    Norrbrand, Lena
    Karolinska Institutet.
    Tesch, Per
    Knee extensor and plantar flexor muscle size and function in response to 90 d bed rest with or without resistance exercise2004Inngår i: 7th Scandinavian Congress on Medicine and Science in Sports, 2004Konferansepaper (Fagfellevurdert)
  • 36. Alkner, Björn
    et al.
    Tesch, Per A
    Mittuniversitetet, Fakulteten för humanvetenskap, Institutionen för hälsovetenskap.
    Efficacy of a gravity-independent resistance exercise device as a countermeasure to muscle atrophy during 29-day bed rest.2004Inngår i: Acta Physioloogica Scandinavica, ISSN 0001-6772, Vol. 181, nr 3, s. 345-357Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study determined changes in knee extensor and plantar flexor muscle volume during 29 days of bed rest with or without resistance exercise using a gravity-independent flywheel ergometer. METHODS: Seventeen men (26-41 years) were subjected to 29 days of bed rest with (n = 8) or without (n = 9) resistance exercise; Supine Squat (SS) and Calf Press (CP) performed every third day. Quadriceps and triceps surae muscle volume was determined before and after bed rest and force and power were measured during training. Prior to these interventions, reproducibility of this device for training and testing was assessed in 23 subjects who performed bilateral maximal concentric, eccentric and isometric (MVC) knee extensions and plantar flexions over repeated sessions with simultaneous measurements of force, power and electromyographic (EMG) activity. RESULTS: Quadriceps and triceps surae muscle volume decreased (P < 0.05) 10 and 16%, respectively, after 29 days bed rest. Exercise maintained quadriceps volume and mitigated triceps surae atrophy. Thus, either muscle showed different response across subject groups (P < 0.05). Force and power output during training were either maintained (P > 0.05) or increased (P < 0.05). EMG amplitude in the training mode was similar (SS; P > 0.05) or greater (CP; P < 0.05) compared with that elicited during MVC. Peak force and power test-retest coefficient of variation (CV) ranged 5-6% and 7-8% for SS and CP, respectively. CONCLUSION: The present data suggest that this resistance exercise paradigm counteracts quadriceps and abates the more substantial triceps surae muscle atrophy in bedridden subjects, and therefore should be an important asset to space travellers.

  • 37.
    Al-Lashi, Lord Laith Zuhair
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    GABA and SGLT2 inhibitor modulate human T lymphocyte effector function2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Sodium Glucose Co-Transporter 2 (SGLT2) inhibitors are one of the dominant drug groups used today for treatment of type 2 diabetes. There are several agents within the group that were investigated in this project: Phlorizin, Empagliflozin, Canagliflozin, Dapagliflozin and Ipragliflozin. SGLT2 inhibitors influence immune cells such as CD4+ T cells, and Gamma Aminobutyric Acid (GABA) also affects CD4+ T cells functions. This study aims to investigate how different SGLT2 inhibitors together with GABA in the presence/absence of insulin affect the effector function of CD4+ T cells. As these are very popular and usable substances in medical fields, it becomes an important basis to study what effect they have on CD4+ T cells effector functions.

    Peripheral Blood Mononuclear Cells (PBMCs) were collected from buffy coat of healthy donors to isolate CD4+ T cells. Cells were activated with anti-CD3 antibody and incubated with different concentrations of SGLT2 inhibitors at 5 mM and 16.7 mM glucose and examined by MTT assay and culture supernatant was collected. Empagliflozin (1uM and 10 uM) was chosen to proceed with to test together with GABA and insulin on CD4+ T cells. Western blot was performed to detect the SGLT2 protein and Sandwich IFNg ELISA was also performed to examine how cytokines such as IFNg were affected in the samples. 

    The presented results show that the SGLT2 protein can be detected in the samples and the IFNg levels were decreased in samples without insulin and increased with the addition of insulin as expected. This should be further investigated, and additional experiments need to be performed to confirm the effect on the CD4+ T cell effector functions.

  • 38.
    Almgren, Birgitta
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Endotracheal Suction a Reopened Problem2005Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    During mechanical ventilation, patients are connected to the ventilator by an endotracheal tube. The tube needs to be cleaned from mucus by suction, which can cause negative effects such as lung collapse, hypoxemia and desaturation. These can be avoided by preoxygenation, change of ventilator settings, use of closed suction systems and recruitment manoeuvres. The aim of the study was to investigate the effects of endotracheal suction during different ventilator settings and by different suction methods. A method to reverse side effects was investigated.

    In anaesthetized pigs, the effect of suction during volume and pressure-controlled ventilation was investigated, and the effect of different suction systems and catheter sizes were compared. Suction efficacy was investigated in a bench study. The effect of recruitment manoeuvre added after suction, i.e. post-suction recruitment manoeuvre was evaluated.

    Endotracheal suction causes lung volume loss leading to impaired gas exchange, an effect that is more severe in pressure-controlled ventilation than in volume-controlled ventilation. When 14 French suction catheters were used more side effects were found compared to 12 French catheters, but no difference was found between open and closed suction system in pressure-controlled ventilation. Open suction system was more effective to remove mucus compared to closed system. Post-suction recruitment manoeuvre restored the side effects after the first recruitment when it was applied directly after suction.

    In conclusion, open endotracheal suction causes impairment in gas exchange and lung mechanics, and more so in pressure-controlled than in volume-controlled mode. These changes can be minimized if smaller suction catheters are used. A post-suction recruitment manoeuvre applied directly after suction restores lung function. It is obvious that the recruitment manoeuvre should be added directly after suction, because if the manoeuvre is delayed and the lung is collapsed and left collapsed, it will be more difficult to recruit the lung.

    Fulltekst (pdf)
    FULLTEXT01
  • 39.
    Almgren, Birgitta
    et al.
    Uppsala universitet, Medicinska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi.
    Strid, Niklas
    Wickerts, Carl-Johan
    Högman, Marieann
    Negative tracheal pressure during suction differs between suction systems and catheter sizes2005Artikkel i tidsskrift (Fagfellevurdert)
  • 40.
    Almgren, Birgitta
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Wickerts, Carl-Johan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Heinonen, Erkki
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Högman, Marieann
    Side effects of endotracheal suction in pressure and volume controlled ventilation2004Inngår i: Chest, ISSN 0012-3692, E-ISSN 1931-3543, Vol. 125, nr 3, s. 1077-1080Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    STUDY OBJECTIVES:

    To investigate the effects of endotracheal suction in volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) with an open suction system (OSS) or a closed suction system (CSS).

    DESIGN:

    Randomized comparison.

    SETTING:

    Animal research laboratory.

    PATIENTS:

    Twelve healthy anesthetized pigs.

    INTERVENTIONS:

    The effects of endotracheal suction during VCV and PCV with tidal volume (VT) of 14 mL/kg were compared. A 60-mm inner-diameter endotracheal tube was used. Ten-second suction was performed using OSS and CSS with 12F and 14F catheters connected to - 14 kPa vacuum.

    MEASUREMENTS AND RESULTS:

    Thirty minutes after suction in PCV, VT was still decreased by 27% (p < 0.001), compliance (Crs) by 28% (p < 0.001), and PaO(2) by 26% (p < 0.001); PaCO(2) was increased by 42% (p < 0.0001) and venous admixture by 158% (p = 0.003). Suction in VCV affected only Crs (decreased by 23%, p < 0.001) and plateau pressure (increased by 24%, p < 0.001). The initial impairment of gas exchange following suction in VCV was no longer statistically significant after 30 min.

    CONCLUSIONS:

    In conclusion, endotracheal suction causes lung collapse leading to impaired gas exchange, an effect that is more severe and persistent in PCV than in VCV.

  • 41.
    Almgren, Birgitta
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Wickerts, Carl-Johan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinsk cellbiologi, Integrativ Fysiologi.
    Högman, Marieann
    Post-suction recruitment manoeuvre restores lung function in healthy, anaesthetized pigs2004Inngår i: Anaesthesia and Intensive Care, ISSN 0310-057X, E-ISSN 1448-0271, Vol. 32, nr 3, s. 339-345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Endotracheal suction can cause partial lung collapse and hypoxia and alter lung mechanics. We investigated the effects of adding a recruitment manoeuvre directly after endotracheal suction to restore lung volume in volume-controlled ventilation and pressure-controlled ventilation modes. Five anaesthetized pigs were investigated. The effects of endotracheal suction with or without a recruitment manoeuvre were compared in random order. In volume-controlled ventilation, compliance decreased after suction from 33 +/- 5 to 26 +/- 6 ml x cmH2O(-1) (P<0.05), and 30 minutes later it remained decreased at 25 +/- 6 ml x cmH2O(-1). Venous admixture increased after suction from 5 +/- 2 to 8 +/- 4% (P<0.05), but had recovered at 30 minutes. In pressure-controlled ventilation, compliance decreased after suction from 34 +/- 3 to 25 +/- 7 ml x cmH2O(-1) (P<0.05), and 30 minutes later it remained decreased at 25 +/- 7 ml x cmH2O(-1). Venous admixture increased after suction from 5 +/- 2 to 13 +/- 7% (P<0.05), and had not recovered after 30 minutes, 10 +/- 4%. When a recruitment manoeuvre was applied directly after suction, no negative side-effects were registered in volume-controlled ventilation or pressure-controlled ventilation. We conclude that the impairment of lung mechanics and gas exchange induced by endotracheal suction can be prevented by a simple post-suction recruitment manoeuvre. Further studies are needed to identify a suitable suction recruitment manoeuvre in patients with diseased lungs.

  • 42.
    Almon, Ricardo
    et al.
    Örebro universitet, Institutionen för klinisk medicin.
    Alvarez-Leon, Eva E.
    Engfeldt, Peter
    Örebro universitet, Institutionen för klinisk medicin.
    Serra-Majem, Lluis
    Magnuson, Anders
    Nilsson, Torbjörn K.
    Associations between lactase persistence and the metabolic syndrome: a Mendelian randomization study in the Canary Islands2009Konferansepaper (Fagfellevurdert)
  • 43.
    Almon, Ricardo
    et al.
    Örebro universitet, Institutionen för klinisk medicin.
    Alvarez-Leon, Eva E.
    Univ Las Palmas Gran Canaria, Fac Hlth Sci, Dept Clin Sci, Canary Isl, Spain; Hosp Insular Gran Canaria, Canarian Hlth Serv, Serv Prevent Med, Canary Isl, Spain.
    Engfeldt, Peter
    Örebro universitet, Institutionen för klinisk medicin.
    Serra-Majem, Lluis
    Univ Las Palmas Gran Canaria, Fac Hlth Sci, Dept Clin Sci, Canary Isl, Spain; Hosp Insular Gran Canaria, Canarian Hlth Serv, Serv Prevent Med, Canary Isl, Spain.
    Magnuson, Anders
    Örebro University hospital, Örebro, Sweden.
    Nilsson, Torbjörn K.
    Örebro University hospital, Örebro, Sweden.
    Associations between lactase persistence and the metabolic syndrome in a cross-sectional study in the Canary Islands2009Inngår i: European Journal of Nutrition, ISSN 1436-6207, E-ISSN 1436-6215, Vol. 49, nr 3, s. 141-146Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The single nucleotide polymorphism (SNP) LCT -13910 C>T, associated with genetically determined phenotypes of lactase persistence (LP) or non-persistence (LNP), was studied in relation to the metabolic syndrome (MS).

    AIim of the study: The aim was to determine if milk intake and MS are associated. We applied Mendelian randomization (MR). The SNP, LCT -13910 C>T, with the genotypes LP (TT/CT) and LNP (CC), was taken as a proxy for milk consumption.

    Methods: A representative sample of adults belonging to the Canary Islands Nutrition Survey (ENCA) in Spain aged 18-75 years (n = 551) was genotyped for the LCT -13910 C>T polymorphism. We used the International Diabetes Federation (IDF) criteria to define MS. RESULTS: 60% of the population was LP and 40% LNP. One hundred seven LP subjects (35.0%) and 53 LNP subjects (25.6%) showed MS (chi (2) = 5.04, p = 0.025). LP subjects showed a significantly higher odds ratio (OR) for MS than LNP subjects computed for the whole population: both the crude OR (1.56; 95% CI 1.06-2.31) and adjusted OR for sex, age, daily energy intake, physical activity and educational level (1.57; 95% CI 1.02-2.43). Adjusted OR for women with LP was 1.93; 95% CI 1.06-3.52.

    Conclusions: The T allele of the SNP might constitute a nutrigenetic factor increasing the susceptibility of LP subjects, especially women, to develop MS in the Canary Islands.

  • 44.
    Alstermark, Bror
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Ekerot, Carl-Fredrik
    Department of Experimental Medical Sciences, Section for Neuroscience, Lund.
    The lateral reticular nucleus: a precerebellar centre providing the cerebellum with overview and integration of motor functions at systems level. A new hypothesis.2013Inngår i: Journal of Physiology, ISSN 0022-3751, E-ISSN 1469-7793, Vol. 591, nr 22, s. 5453-5458Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The lateral reticular nucleus (LRN) is a major precerebellar centre of mossy fibre information to the cerebellum from the spinal cord that is distinct from the direct spinocerebellar paths. The LRN has traditionally been considered to provide the cerebellum with segregated information from several spinal systems controlling posture, reaching, grasping, locomotion, scratching and respiration. However, results are presented that show extensive convergence on a majority of LRN neurons from spinal systems. We propose a new hypothesis suggesting that the LRN may use extensive convergence from the different input systems to provide overview and integration of linked motor components to the cerebellum. This integrated information is sent in parallel with the segregated information from the individual systems to the cerebellum that finally may compare the activity and make necessary adjustments of various motor behaviours.

  • 45.
    Alstermark, Bror
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Isa, Tadashi
    Premotoneuronal and direct corticomotoneuronal control in the cat and macaque monkey.2002Inngår i: Advances in Experimental Medicine and Biology, ISSN 0065-2598, E-ISSN 2214-8019, Vol. 508, s. 281-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The literature on premotoneuronal and direct corticomotoneuronal (CM) control in the cat and macaque monkey is reviewed. The available experimental findings are not in accordance with a recently proposed hypothesis that direct CM connections have "replaced" the premotoneuronal pathways. Instead, we propose that premotoneuronal CM control plays an important role in motor control also in primates and that the direct CM connection has been added during phylogeny.

  • 46.
    Alstermark, Bror
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för integrativ medicinsk biologi (IMB), Fysiologi.
    Pettersson, L G
    University of Gothenburg.
    Nishimura, Y
    National Institute for Physiological Sciences, Okazaki.
    Yoshino-Saito, K
    National Institute for Physiological Sciences, Okazaki.
    Tsuboi, F
    National Institute for Physiological Sciences, Okazaki.
    Takahashi, M
    National Institute for Physiological Sciences, Okazaki.
    Isa, T
    National Institute for Physiological Sciences, Okazaki.
    Motor command for precision grip in the macaque monkey can be mediated by spinal interneurons2011Inngår i: Journal of Neurophysiology, ISSN 0022-3077, E-ISSN 1522-1598, Vol. 106, nr 1, s. 122-126Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In motor control, the general view is still that spinal interneurons mainly contribute to reflexes and automatic movements. The question raised here is whether spinal interneurons can mediate the cortical command for independent finger movements, like a precision grip between the thumb and index finger in the macaque monkey, or if this function depends exclusively on a direct corticomotoneuronal pathway. This study is a followup of a previous report (Sasaki et al. J Neurophysiol 92: 3142-3147, 2004) in which we trained macaque monkeys to pick a small piece of sweet potato from a cylinder by a precision grip between the index finger and thumb. We have now isolated one spinal interneuronal system, the C3-C4 propriospinal interneurons with projection to hand and arm motoneurons. In the previous study, the lateral corticospinal tract (CST) was interrupted in C4/C5 (input intact to the C3-C4 propriospinal interneurons), and in this study, the CST was interrupted in C2 (input abolished). The precision grip could be performed within the first 15 days after a CST lesion in C4/C5 but not in C2. We conclude that C3-C4 propriospinal interneurons also can carry the command for precision grip.

  • 47.
    Amandusson, Åsa
    et al.
    Division of Cell Biology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University.
    Blomqvist, Anders
    Estrogen receptor-α expression in nociceptive-responsive neurons in the medullary dorsal horn of the female rat2010Inngår i: European Journal of Pain, ISSN 1090-3801, E-ISSN 1532-2149, Vol. 14, nr 3, s. 245-248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Estrogens exert a substantial influence on the transmission of nociceptive stimuli and the susceptibility to pain disorders as made evident by studies in both animals and human subjects. The estrogen receptor (ER) seems to be of crucial importance to the cellular mechanisms underlying such an influence. However, it has not been clarified whether nociceptive neurons activated by pain express ERs. In this study, a noxious injection of formalin was given into the lower lip of female rats, thereby activating nociceptive neurons in the trigeminal subnucleus caudalis as demonstrated by immunohistochemical labeling of Fos. Using a dual-label immunohistochemistry protocol ERalpha-containing cells were visualized in the same sections. In the superficial layers of the medullary dorsal horn, 12% of ERalpha-labeled cells, mainly located in lamina II, also expressed noxious-induced Fos. These findings show that nociceptive-responsive neurons in the medullary dorsal horn express ERalpha, thus providing a possible morphological basis for the hypothesis that estrogens directly regulate pain transmission at this level.

  • 48.
    Amandusson, Åsa
    et al.
    Linköpings Universitet.
    Hermansson, O
    Blomqvist, A
    Estrogen receptor-like immunoreactivity in the medullary and spinal dorsal horn of the female rat1995Inngår i: Neuroscience Letters, ISSN 0304-3940, E-ISSN 1872-7972, Vol. 196, nr 1-2, s. 25-28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Using an immunohistochemical technique, we demonstrate that large numbers of neurons in the laminar spinal trigeminal nucleus and spinal gray matter of the female rat express estrogen receptors (ER). Densely packed ER-immunoreactive neurons were present in lamina II, but labeled neurons were also present in lamina I, the neck of the dorsal horn, and in lamina X. Labeling was present throughout the length of the spinal cord, with the exception of segments caudal to S1, which were unlabeled. The distribution of ER-containing neurons to areas that are involved in processing of primary afferent nociceptive information suggests that the pain modulatory effects of estrogen may be exerted at the spinal level.

  • 49. Ambrosio, Fabrisia
    et al.
    Kadi, Fawzi
    Örebro universitet, Institutionen för hälsovetenskap och medicin.
    Lexell, Jan
    Fitzgerald, G. Kelley
    Boninger, Michael L.
    Huard, Johnny
    The effect of muscle loading on skeletal muscle regenerative potential: an update of current research findings relating to aging and neuromuscular pathology2009Inngår i: American Journal of Physical Medicine & Rehabilitation, ISSN 0894-9115, E-ISSN 1537-7385, Vol. 88, nr 2, s. 145-155Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Skeletal muscle is a dynamic tissue with a remarkable ability to continuously respond to environmental stimuli. Among its adaptive responses is the widely investigated ability of skeletal muscle to regenerate after loading or injury or both. Although significant basic science efforts have been dedicated to better understand the underlying mechanism controlling skeletal muscle regeneration, there has been relatively little impact in the clinical approaches used to treat skeletal muscle injuries and wasting. The purpose of this review article is to provide an overview of the basic biology of satellite cell function in response to muscle loading and to relate these findings in the context of aging and neuromuscular pathology for the rehabilitation medicine specialist.

  • 50. Ammari, Rachida
    et al.
    Broberger, Christian
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för biokemi och biofysik. Karolinska Institutet, Sweden.
    Pre- and post-synaptic modulation by GABA(B) receptors of rat neuroendocrine dopamine neurones2020Inngår i: Journal of neuroendocrinology (Print), ISSN 0953-8194, E-ISSN 1365-2826, Vol. 32, nr 11, artikkel-id e12881Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The secretion of prolactin from the pituitary is negatively controlled by tuberoinfundibular dopamine (TIDA) neurones. The electrical properties of TIDA cells have recently been identified as a modulatory target of neurotransmitters and hormones in the lactotrophic axis. The role of the GABA(B) receptor in this control has received little attention, yet is of particular interest because it may act as a TIDA neurone autoreceptor. Here, this issue was explored in a spontaneously active rat TIDA in vitro slice preparation using whole-cell recordings. Application of the GABA(B) receptor agonist, baclofen, dose-dependently slowed down or abolished the network oscillations typical of this preparation. Pharmacological manipulations identify the underlying mechanism as an outward current mediated by G-protein-coupled inwardly rectifying K+-like channels. In addition to this postsynaptic modulation, we describe a presynaptic modulation where GABA(B) receptors restrain the release of glutamate and GABA onto TIDA neurones. Our data identify both pre- and postsynaptic modulation of TIDA neurones by GABA(B) receptors that may play a role in the neuronal network control of pituitary prolactin secretion and lactation.

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