Apps i anatomiundervisningen - perspektiver for et nyt learning design

Dansk Formålet med denne artikel var at diskutere, hvordan Learning Design kan anvendes ved implementering af mobile platforme i undervisningen på universitetsniveau. Med udgangspunkt i teoretiske modeller og undervisernes overvejelser diskuteres brug af Learning Design og implementering informationsteknologi med afsæt i anvendelse af applikationer til tablets og smartphones i anatomiundervisningen på Aarhus Universitet. Sekundært præsenterer artiklen resultater fra et pilotprojekt i anatomiundervisningen på medicinstudiet, Aarhus Universitet, der viser, at de studerende er positivt indstillede over for informationsteknologi i undervisningen, at de er teknologiparate, og at anatomiapplikationerne forbedrer de studerendes oplevelse af tredimensional forståelse. Ved anvendelse af et veltilrettelagt Learning Design kan undervisningssessioner og kurser designes til i højere grad at anvende informations- og uddannelsesteknologi i integrerede læringsforløb. English The purpose of the this study was to discuss how Learning Design can be used when implementing mobile learning devices in education at universities. Based on theoretical models and the teachers’ thoughts and reflections, the use of Learning Design and implementation of information technology is discussed on the basis of using tablets and smartphones with anatomy specific applications in anatomy courses at the School of medicine, Aarhus University, Denmark. Secondarily, the results from a pilot project including tablets in anatomy teaching are presented, showing that the students have a positive attitude towards information technology in education, that they are used to using information technology in education, and that anatomy applications improve the students’ understanding of anatomy in three dimensions. By application of a well-designed Learning Design, teaching sessions can implement information- and educational technology in a combination of in-class and out-of-class

Imaging Neurodegenerative Metabolism in Amyotrophic Lateral Sclerosis with Hyperpolarized [1-13C]pyruvate MRI

The cause of amyotrophic lateral sclerosis (ALS) is still unknown, and consequently, early diagnosis of the disease can be difficult and effective treatment is lacking. The pathology of ALS seems to involve specific disturbances in carbohydrate metabolism, which may be diagnostic and therapeutic targets. Magnetic resonance imaging (MRI) with hyperpolarized [1-(13)C]pyruvate is emerging as a technology for the evaluation of pathway-specific changes in the brain’s metabolism. By imaging pyruvate and the lactate and bicarbonate it is metabolized into, the technology is sensitive to the metabolic changes of inflammation and mitochondrial dysfunction. In this study, we performed hyperpolarized MRI of a patient with newly diagnosed ALS. We found a lateralized difference in [1-(13)C]pyruvate-to-[1-(13)C]lactate exchange with no changes in exchange from [1-(13)C]pyruvate to (13)C-bicarbonate. The 40% increase in [1-(13)C]pyruvate-to-[1-(13)C]lactate exchange corresponded with the patient’s symptoms and presentation with upper-motor neuron affection and cortical hyperexcitability. The data presented here demonstrate the feasibility of performing hyperpolarized MRI in ALS. They indicate potential in pathway-specific imaging of dysfunctional carbohydrate metabolism in ALS, an enigmatic neurodegenerative disease

Lactate saturation limits bicarbonate detection in hyperpolarized 13 C-pyruvate MRI of the brain

PURPOSE: To investigate the potential effects of [1‐(13)C]lactate RF saturation pulses on [(13)C]bicarbonate detection in hyperpolarized [1‐(13)C]pyruvate MRI of the brain. METHODS: Thirteen healthy rats underwent MRI with hyperpolarized [1‐(13)C]pyruvate of either the brain (n = 8) or the kidneys, heart, and liver (n = 5). Dynamic, metabolite‐selective imaging was used in a cross‐over experiment in which [1‐(13)C]lactate was excited with either 0° or 90° flip angles. The [(13)C]bicarbonate SNR and apparent [1‐(13)C]pyruvate‐to‐[(13)C]bicarbonate conversion (k (PB)) were determined. Furthermore, simulations were performed to identify the SNR optimal flip‐angle scheme for detection of [1‐(13)C]lactate and [(13)C]bicarbonate. RESULTS: In the brain, the [(13)C]bicarbonate SNR was 64% higher when [1‐(13)C]lactate was not excited (5.8 ± 1.5 vs 3.6 ± 1.3; 1.2 to 3.3–point increase; p = 0.0027). The apparent k (PB) decreased 25% with [1‐(13)C]lactate saturation (0.0047 ± 0.0008 s(−1) vs 0.0034 ± 0.0006 s(−1); 95% confidence interval, 0.0006–0.0019 s(−1) increase; p = 0.0049). These effects were not present in the kidneys, heart, or liver. Simulations suggest that the optimal [(13)C]bicarbonate SNR with a TR of 1 s in the brain is obtained with [(13)C]bicarbonate, [1‐(13)C]lactate, and [1‐(13)C]pyruvate flip angles of 60°, 15°, and 10°, respectively. CONCLUSIONS: Radiofrequency saturation pulses on [1‐(13)C]lactate limit [(13)C]bicarbonate detection in the brain specifically, which could be due to shuttling of lactate from astrocytes to neurons. Our results have important implications for experimental design in studies in which [(13)C]bicarbonate detection is warranted

Detection of increased pyruvate dehydrogenase flux in the human heart during adenosine stress test using hyperpolarized [1-13C]pyruvate cardiovascular magnetic resonance imaging

BACKGROUND: Hyperpolarized (HP) [1-(13)C]pyruvate cardiovascular magnetic resonance (CMR) imaging can visualize the uptake and intracellular conversion of [1-(13)C]pyruvate to either [1-(13)C]lactate or (13)C-bicarbonate depending on the prevailing metabolic state. The aim of the present study was to combine an adenosine stress test with HP [1-(13)C]pyruvate CMR to detect cardiac metabolism in the healthy human heart at rest and during moderate stress. METHODS: A prospective descriptive study was performed between October 2019 and August 2020. Healthy human subjects underwent cine CMR and HP [1-(13)C]pyruvate CMR at rest and during adenosine stress. HP [1-(13)C]pyruvate CMR images were acquired at the mid-left-ventricle (LV) level. Semi-quantitative assessment of first-pass myocardial [1-(13)C]pyruvate perfusion and metabolism were assessed. Paired t-tests were used to compare mean values at rest and during stress. RESULTS: Six healthy subjects (two female), age 29 ± 7 years were studied and no adverse reactions occurred. Myocardial [1-(13)C]pyruvate perfusion was significantly increased during stress with a reduction in time-to-peak from 6.2 ± 2.8 to 2.7 ± 1.3 s, p = 0.02. This higher perfusion was accompanied by an overall increased myocardial uptake and metabolism. The conversion rate constant (k(PL)) for lactate increased from 11 ± 9 *10(–3) to 20 ± 10 * 10(–3) s(−1), p = 0.04. The pyruvate oxidation rate (k(PB)) increased from 4 ± 4 *10(–3) to 12 ± 7 *10(–3) s(−1), p = 0.008. This increase in carbohydrate metabolism was positively correlated with heart rate (R(2) = 0.44, p = 0.02). CONCLUSIONS: Adenosine stress testing combined with HP [1-(13)C]pyruvate CMR is feasible and well-tolerated in healthy subjects. We observed an increased pyruvate oxidation during cardiac stress. The present study is an important step in the translation of HP [1-(13)C]pyruvate CMR into clinical cardiac imaging. Trial registration EUDRACT, 2018-003533-15. Registered 4th of December 2018, https://www.clinicaltrialsregister.eu/ctr-search/search?query=2018-003533-1

Current Methods for Hyperpolarized [1-13C]pyruvate MRI Human Studies

MRI with hyperpolarized (HP) 13C agents, also known as HP 13C MRI, can measure processes such as localized metabolism that is altered in numerous cancers, liver, heart, kidney diseases, and more. It has been translated into human studies during the past 10 years, with recent rapid growth in studies largely based on increasing availability of hyperpolarized agent preparation methods suitable for use in humans. This paper aims to capture the current successful practices for HP MRI human studies with [1-13C]pyruvate - by far the most commonly used agent, which sits at a key metabolic junction in glycolysis. The paper is divided into four major topic areas: (1) HP 13C-pyruvate preparation, (2) MRI system setup and calibrations, (3) data acquisition and image reconstruction, and (4) data analysis and quantification. In each area, we identified the key components for a successful study, summarized both published studies and current practices, and discuss evidence gaps, strengths, and limitations. This paper is the output of the HP 13C MRI Consensus Group as well as the ISMRM Hyperpolarized Media MR and Hyperpolarized Methods & Equipment study groups. It further aims to provide a comprehensive reference for future consensus building as the field continues to advance human studies with this metabolic imaging modality

A genetically modified minipig model for Alzheimer's disease with SORL1 haploinsufficiency

The established causal genes in Alzheimer’s disease (AD), APP, PSEN1, and PSEN2, are functionally characterized using biomarkers, capturing an in vivo profile reflecting the disease’s initial preclinical phase. Mutations in SORL1, encoding the endosome recycling receptor SORLA, are found in 2%–3% of individuals with early-onset AD, and SORL1 haploinsufficiency appears to be causal for AD. To test whether SORL1 can function as an AD causal gene, we use CRISPR-Cas9-based gene editing to develop a model of SORL1 haploinsufficiency in Göttingen minipigs, taking advantage of porcine models for biomarker investigations. SORL1 haploinsufficiency in young adult minipigs is found to phenocopy the preclinical in vivo profile of AD observed with APP, PSEN1, and PSEN2, resulting in elevated levels of β-amyloid (Aβ) and tau preceding amyloid plaque formation and neurodegeneration, as observed in humans. Our study provides functional support for the theory that SORL1 haploinsufficiency leads to endosome cytopathology with biofluid hallmarks of autosomal dominant AD