75 results on '"Andersen KB"'
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2. Healthy brain aging assessed with [18F]FDG and [11 C]UCB-J PET
- Author
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Andersen KB, Hansen AK, Knudsen K, Schacht AC, Damholdt MF, Brooks DJ, Borghammer P
- Published
- 2022
- Full Text
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3. The orphan G protein-coupled receptor GPR139 is activated by the peptides: Adrenocorticotropic hormone (ACTH), α-, and β-melanocyte stimulating hormone (α-MSH, and β-MSH), and the conserved core motif HFRW
- Author
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Nøhr, AC, Shehata, MA, Hauser, AS, Isberg, V, Mokrosinski, J, Andersen, KB, Farooqi, IS, Pedersen, DS, Gloriam, DE, and Bräuner-Osborne, H
- Subjects
endocrine system ,Adrenocorticotropic hormone (ACTH) ,Peptide receptor ,Melanocyte stimulating hormone (MSH) ,Orphan GPCR ,GPR139 ,hormones, hormone substitutes, and hormone antagonists ,3. Good health ,Pro-opiomelanocortin (POMC) - Abstract
GPR139 is an orphan G protein-coupled receptor that is expressed primarily in the brain. Not much is known regarding the function of GPR139. Recently we have shown that GPR139 is activated by the amino acids l-tryptophan and l-phenylalanine (EC50 values of 220 μM and 320 μM, respectively), as well as di-peptides comprised of aromatic amino acids. This led us to hypothesize that GPR139 may be activated by peptides. Sequence alignment of the binding cavities of all class A GPCRs, revealed that the binding pocket of the melanocortin 4 receptor is similar to that of GPR139. Based on the chemogenomics principle "similar targets bind similar ligands", we tested three known endogenous melanocortin 4 receptor agonists; adrenocorticotropic hormone (ACTH) and α- and β-melanocyte stimulating hormone (α-MSH and β-MSH) on CHO-k1 cells stably expressing the human GPR139 in a Fluo-4 Ca(2+)-assay. All three peptides, as well as their conserved core motif HFRW, were found to activate GPR139 in the low micromolar range. Moreover, we found that peptides consisting of nine or ten N-terminal residues of α-MSH activate GPR139 in the submicromolar range. α-MSH1-9 was found to correspond to the product of a predicted cleavage site in the pre-pro-protein pro-opiomelanocortin (POMC). Our results demonstrate that GPR139 is a peptide receptor, activated by ACTH, α-MSH, β-MSH, the conserved core motif HFRW as well as a potential endogenous peptide α-MSH1-9. Further studies are needed to determine the functional relevance of GPR139 mediated signaling by these peptides.
4. Correlation between dopaminergic and metabolic asymmetry in Lewy body disease - A dual-imaging study.
- Author
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Horsager J, Andersen KB, Okkels N, Knudsen K, Skjærbæk C, Van Den Berge N, Pavese N, Gottrup H, and Borghammer P
- Subjects
- Humans, Female, Male, Aged, Parkinson Disease diagnostic imaging, Parkinson Disease metabolism, Middle Aged, Dopamine metabolism, Aged, 80 and over, Putamen diagnostic imaging, Putamen metabolism, Connectome, Lewy Body Disease diagnostic imaging, Lewy Body Disease metabolism, Positron-Emission Tomography, Fluorodeoxyglucose F18
- Abstract
Introduction: The a-Synuclein Origin and Connectome (SOC) model of Lewy body diseases postulates that a-syuclein will be asymmetrically distributed in some patients with Lewy body diseases, potentially leading to asymmetric neuronal dysfunction and symptoms., Methods: We included two patient groups: 19 non-demented Parkinson's disease (nPD) patients with [
18 F]FDG PET and motor symptoms assessed by UPDRS-III, and 65 Lewy body dementia (LBD) patients with [18 F]FDG PET and dopamine radioisotope imaging. Asymmetry indices were calculated for [18 F]FDG PET by including the cortex for each hemisphere, for dopamine radioisotope imaging by including the putamen and caudate separately, and for motor symptoms by using the difference between right-left UPDRS-III score. Correlations between these asymmetry indices were explored to test the predictions of the SOC model. To identify cases with a more typical LBD imaging profile, we calculated a Cingulate Island Sign (CIS) index on the [18 F]FDG PET image., Results: We found a significant correlation between cortical interhemispheric [18 F]FDG asymmetry and motor-symptom asymmetry in nPD patients (r = 0.62, P = 0.004). In patients with LBD, we found a significant correlation between cortical interhemispheric [18 F]FDG asymmetry and dopamine transporter asymmetry in the caudate (r = 0.37, P = 0.0019), but not in the putamen (r = 0.15, P = 0.22). We observed that the correlation in the caudate was stronger in LBD subjects with the highest CIS index, i.e., with more typical LBD imaging profiles., Conclusion: Our study partly supports the SOC model, but further investigations are needed - ideally of de novo, non-demented PD patients., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Per Borghammer reports financial support was provided by Lundbeck Foundation. Jacob Horsager reports financial support was provided by Lundbeck Foundation. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2024
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5. Impaired cholinergic integrity of the colon and pancreas in dementia with Lewy bodies.
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Okkels N, Horsager J, Fedorova TD, Knudsen K, Skjærbæk C, Andersen KB, Labrador-Espinosa M, Vestergaard K, Mortensen JK, Klit H, Møller M, Danielsen EH, Johnsen EL, Bekan G, Hansen KV, Munk OL, Damholdt MF, Kjeldsen PL, Hansen AK, Gottrup H, Grothe MJ, and Borghammer P
- Subjects
- Humans, Male, Aged, Female, Cross-Sectional Studies, Pancreas pathology, Cholinergic Agents, Colon pathology, Lewy Body Disease diagnostic imaging, Lewy Body Disease pathology, Autonomic Nervous System Diseases diagnostic imaging, Autonomic Nervous System Diseases etiology
- Abstract
Dementia with Lewy bodies is characterized by a high burden of autonomic dysfunction and Lewy pathology in peripheral organs and components of the sympathetic and parasympathetic nervous system. Parasympathetic terminals may be quantified with 18F-fluoroetoxybenzovesamicol, a PET tracer that binds to the vesicular acetylcholine transporter in cholinergic presynaptic terminals. Parasympathetic imaging may be useful for diagnostics, improving our understanding of autonomic dysfunction and for clarifying the spatiotemporal relationship of neuronal degeneration in prodromal disease. Therefore, we aimed to investigate the cholinergic parasympathetic integrity in peripheral organs and central autonomic regions of subjects with dementia with Lewy bodies and its association with subjective and objective measures of autonomic dysfunction. We hypothesized that organs with known parasympathetic innervation, especially the pancreas and colon, would have impaired cholinergic integrity. To achieve these aims, we conducted a cross-sectional comparison study including 23 newly diagnosed non-diabetic subjects with dementia with Lewy bodies (74 ± 6 years, 83% male) and 21 elderly control subjects (74 ± 6 years, 67% male). We obtained whole-body images to quantify PET uptake in peripheral organs and brain images to quantify PET uptake in regions of the brainstem and hypothalamus. Autonomic dysfunction was assessed with questionnaires and measurements of orthostatic blood pressure. Subjects with dementia with Lewy bodies displayed reduced cholinergic tracer uptake in the pancreas (32% reduction, P = 0.0003) and colon (19% reduction, P = 0.0048), but not in organs with little or no parasympathetic innervation. Tracer uptake in a region of the medulla oblongata overlapping the dorsal motor nucleus of the vagus correlated with autonomic symptoms (rs = -0.54, P = 0.0077) and changes in orthostatic blood pressure (rs = 0.76, P < 0.0001). Tracer uptake in the pedunculopontine region correlated with autonomic symptoms (rs = -0.52, P = 0.0104) and a measure of non-motor symptoms (rs = -0.47, P = 0.0230). In conclusion, our findings provide the first imaging-based evidence of impaired cholinergic integrity of the pancreas and colon in dementia with Lewy bodies. The observed changes may reflect parasympathetic denervation, implying that this process is initiated well before the point of diagnosis. The findings also support that cholinergic denervation in the brainstem contributes to dysautonomia., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2024
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6. Severe cholinergic terminal loss in newly diagnosed dementia with Lewy bodies.
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Okkels N, Horsager J, Labrador-Espinosa M, Kjeldsen PL, Damholdt MF, Mortensen J, Vestergård K, Knudsen K, Andersen KB, Fedorova TD, Skjærbæk C, Gottrup H, Hansen AK, Grothe MJ, and Borghammer P
- Subjects
- Humans, Male, Aged, Aged, 80 and over, Middle Aged, Female, Lewy Bodies metabolism, Cross-Sectional Studies, Cholinergic Agents, Atrophy pathology, Lewy Body Disease metabolism
- Abstract
Cholinergic changes play a fundamental role in the natural history of dementia with Lewy bodies and Lewy body disease in general. Despite important achievements in the field of cholinergic research, significant challenges remain. We conducted a study with four main objectives: (i) to examine the integrity of cholinergic terminals in newly diagnosed dementia with Lewy bodies; (ii) to disentangle the cholinergic contribution to dementia by comparing cholinergic changes in Lewy body patients with and without dementia; (iii) to investigate the in vivo relationship between cholinergic terminal loss and atrophy of cholinergic cell clusters in the basal forebrain at different stages of Lewy body disease; and (iv) to test whether any asymmetrical degeneration in cholinergic terminals would correlate with motor dysfunction and hypometabolism. To achieve these objectives, we conducted a comparative cross-sectional study of 25 newly diagnosed dementia with Lewy bodies patients (age 74 ± 5 years, 84% male), 15 healthy control subjects (age 75 ± 6 years, 67% male) and 15 Parkinson's disease patients without dementia (age 70 ± 7 years, 60% male). All participants underwent 18F-fluoroetoxybenzovesamicol PET and high-resolution structural MRI. In addition, we collected clinical 18F-fluorodeoxyglucose PET images. Brain images were normalized to standard space and regional tracer uptake and volumetric indices of basal forebrain degeneration were extracted. Patients with dementia showed spatially distinct reductions in cholinergic terminals across the cerebral cortex, limbic system, thalamus and brainstem. Also, cholinergic terminal binding in cortical and limbic regions correlated quantitatively and spatially with atrophy of the basal forebrain. In contrast, patients without dementia showed decreased cholinergic terminal binding in the cerebral cortex despite preserved basal forebrain volumes. In patients with dementia, cholinergic terminal reductions were most severe in limbic regions and least severe in occipital regions compared to those without dementia. Interhemispheric asymmetry of cholinergic terminals correlated with asymmetry of brain metabolism and lateralized motor function. In conclusion, this study provides robust evidence for severe cholinergic terminal loss in newly diagnosed dementia with Lewy bodies, which correlates with structural imaging measures of cholinergic basal forebrain degeneration. In patients without dementia, our findings suggest that loss of cholinergic terminal function occurs 'before' neuronal cell degeneration. Moreover, the study supports that degeneration of the cholinergic system is important for brain metabolism and may be linked with degeneration in other transmitter systems. Our findings have implications for understanding how cholinergic system pathology contributes to the clinical features of Lewy body disease, changes in brain metabolism and disease progression patterns., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2023
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7. Synaptic Density and Glucose Consumption in Patients with Lewy Body Diseases: An [ 11 C]UCB-J and [ 18 F]FDG PET Study.
- Author
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Andersen KB, Hansen AK, Schacht AC, Horsager J, Gottrup H, Klit H, Danielsen EH, Poston KL, Pavese N, Brooks DJ, and Borghammer P
- Subjects
- Humans, Fluorodeoxyglucose F18, Glucose metabolism, Lewy Bodies metabolism, Positron-Emission Tomography, Brain diagnostic imaging, Brain metabolism, Lewy Body Disease diagnostic imaging, Lewy Body Disease metabolism
- Abstract
Background: Patients with Lewy body diseases exhibit variable degrees of cortical and subcortical hypometabolism. However, the underlying causes behind this progressive hypometabolism remain unresolved. Generalized synaptic degeneration may be one key contributor., Objective: The objective of this study was to investigate whether local cortical synaptic loss is proportionally linked to the magnitude of hypometabolism in Lewy body disease., Method: Using in vivo positron emission tomography (PET) we investigated cerebral glucose metabolism and quantified the density of cerebral synapses, as measured with [
18 F]fluorodeoxyglucose ([18 F]FDG) PET and [11 C]UCB-J, respectively. Volumes-of-interest were defined on magnetic resonance T1 scans and regional standard uptake value ratios-1 values were obtained for 14 pre-selected brain regions. Between-group comparisons were conducted at voxel-level., Results: We observed regional differences in both synaptic density and cerebral glucose consumption in our cohorts of non-demented and demented patients with Parkinson's disease or dementia with Lewy bodies compared to healthy subjects. Additionally, voxel-wise comparisons showed a clear difference in cortical regions between demented patients and controls for both tracers. Importantly, our findings strongly suggested that the magnitude of reduced glucose uptake exceeded the magnitude of reduced cortical synaptic density., Conclusion: Here, we investigated the relationship between in vivo glucose uptake and the magnitude of synaptic density as measured using [18 F]FDG PET and [11 C]UCB-J PET in Lewy body patients. The magnitude of reduced [18 F]FDG uptake was greater than the corresponding decline in [11 C]UCB-J binding. Therefore, the progressive hypometabolism seen in Lewy body disorders cannot be fully explained by generalized synaptic degeneration. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)- Published
- 2023
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8. Distribution of cholinergic nerve terminals in the aged human brain measured with [ 18 F]FEOBV PET and its correlation with histological data.
- Author
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Okkels N, Horsager J, Labrador-Espinosa MA, Hansen FO, Andersen KB, Just MK, Fedorova TD, Skjærbæk C, Munk OL, Hansen KV, Gottrup H, Hansen AK, Grothe MJ, and Borghammer P
- Subjects
- Aged, Female, Humans, Male, Middle Aged, Brain metabolism, Cholinergic Agents, Piperidines, Vesicular Acetylcholine Transport Proteins metabolism, Fluorine Radioisotopes, Electrons, Positron-Emission Tomography methods
- Abstract
Introduction: [
18 F]fluoroetoxybenzovesamicol ([18 F]FEOBV) is a positron emission topography (PET) tracer for the vesicular acetylcholine transporter (VAChT), a protein located predominantly in synaptic vesicles in cholinergic nerve terminals. We aimed to use [18 F]FEOBV PET to study the cholinergic topography of the healthy human brain., Materials and Methods: [18 F]FEOBV PET brain data volumes of healthy elderly humans were normalized to standard space and intensity-normalized to the white matter. Stereotactic atlases of regions of interest were superimposed to describe and quantify tracer distribution. The spatial distribution of [18 F]FEOBV PET uptake was compared with histological and gene expression data., Results: Twenty participants of both sexes and a mean age of 73.9 ± 6.0 years, age-range [64; 86], were recruited. Highest tracer binding was present in the striatum, some thalamic nuclei, and the basal forebrain. Intermediate binding was found in most nuclei of the brainstem, thalamus, and hypothalamus; the vermis and flocculonodular lobe; and the hippocampus, amygdala, insula, cingulate, olfactory cortex, and Heschl's gyrus. Lowest binding was present in most areas of the cerebral cortex, and in the cerebellar nuclei and hemispheres. The spatial distribution of tracer correlated with immunohistochemical post-mortem data, as well as with regional expression levels of SLC18A3, the VAChT coding gene., Discussion: Our in vivo findings confirm the regional cholinergic distribution in specific brain structures as described post-mortem. A positive spatial correlation between tracer distribution and regional gene expression levels further corroborates [18 F]FEOBV PET as a validated tool for in vivo cholinergic imaging. The study represents an advancement in the continued efforts to delineate the spatial topography of the human cholinergic system in vivo., Competing Interests: Declarations of Competing Interest None., (Copyright © 2023. Published by Elsevier Inc.)- Published
- 2023
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9. Healthy brain aging assessed with [ 18 F]FDG and [ 11 C]UCB-J PET.
- Author
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Andersen KB, Hansen AK, Knudsen K, Schacht AC, Damholdt MF, Brooks DJ, and Borghammer P
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- Aged, Brain diagnostic imaging, Brain metabolism, Glucose metabolism, Glycoproteins metabolism, Humans, Positron-Emission Tomography methods, Fluorodeoxyglucose F18 metabolism, Healthy Aging
- Abstract
Background: The average human lifespan has increased dramatically over the past century. However, molecular and physiological alterations of the healthy brain during aging remain incompletely understood. Generalized synaptic restructuring may contribute to healthy aging and the reduced metabolism observed in the aged brain. The aim of this study was to assess healthy brain aging using [
18 F]FDG as a measure of cerebral glucose consumption and [11 C]UCB-J PET as an indicator of synaptic density., Method: Using in vivo PET imaging and the novel synaptic-vesicle-glycoprotein 2A (SV2A) radioligand [11 C]UCB-J alongside with the fluorodeoxyglucose radioligand [18 F]FDG, we obtained SUVR-1 values for 14 pre-defined volume-of-interest brain regions defined on MRI T1 scans. Regional differences in relative [18 F]FDG and [11 C]UCB-J uptake were investigated using a voxel-wise approach. Finally, correlations between [11 C]UCB-J, [18 F]FDG PET, and age were examined., Results: We found widespread cortical reduction of synaptic density in a cohort of older HC subjects (N = 15) compared with young HC subjects (N = 11). However, no reduction persisted after partial volume correction and corrections for multiple comparison. Our study confirms previously reported synaptic stability during aging. Regional differences in relative [18 F]FDG and [11 C]UCB-J uptake were observed with up to 20 % higher [11 C]UCB-J uptake in the amygdala and temporal lobe and up to 34 % higher glucose metabolism in thalamus, striatum, occipital, parietal and frontal cortex., Conclusion: In vivo PET using [11 C]UCB-J does not support declining synaptic density levels during aging. Thus, loss of synaptic density may be unrelated to aging and does not seem to be a sufficient explanation for the recognized reduction in brain metabolism during aging. Our study also demonstrates that the relationship between glucose consumption and synaptic density is not uniform throughout the human brain with implications for our understanding of neuroenergetics., Competing Interests: Declaration of competing interest Nothing to disclose., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2022
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10. Imaging progressive peripheral and central dysfunction in isolated REM sleep behaviour disorder after 3 years of follow-up.
- Author
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Fedorova TD, Knudsen K, Andersen KB, Horsager J, Skjærbæk C, Beier CP, Sommerauer M, Svendsen KB, Otto M, and Borghammer P
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- 3-Iodobenzylguanidine, Dopamine, Follow-Up Studies, Humans, Positron-Emission Tomography methods, Parkinson Disease, REM Sleep Behavior Disorder diagnostic imaging
- Abstract
Introduction: Most patients with isolated rapid eye movement sleep behaviour disorder (iRBD) convert to Parkinson's disease (PD), dementia with Lewy bodies, or multiple system atrophy within 15 years of diagnosis. Furthermore, iRBD patients develop non-motor symptoms similar to those of manifest PD patients and display dysfunction of the sympathetic and parasympathetic nervous system, comparable to that seen in PD. However, progression rates of autonomic dysfunction in iRBD have not been studied with objective measures in detail, which is the aim of this study., Methods: Twenty-two iRBD patients were included at baseline and 14 participated in follow-up after 3 years. Colonic transit time (CTT) was examined using radio opaque markers, colonic volume was defined on abdominal computed tomography (CT) scans, Iodine-123-metaiodobenzylguanidine ([123I]MIBG) scintigraphy was performed to assess cardiac sympathetic innervation, and 3,4-dihydroxy-6-(18F) fluoro-l-phenylalanine ([18F]FDOPA) positron emission tomography (PET) scan determined nigrostriatal dopamine storage capacity. All examinations were performed at baseline and after 3 years., Results: iRBD patients displayed increased CTT (p = 0.001) and colonic volume (p = 0.01) at follow-up compared to baseline. Furthermore, [123I]MIBG uptake and [18F]FDOPA uptake showed progressive reductions at follow-up (p = 0.02 and p = 0.002, respectively). No correlations were seen between changes in intestinal or cardiac measurements and dopaminergic function., Conclusion: Using objective markers, the present study documented that intestinal dysfunction and cardiac sympathetic degeneration worsen in the majority of iRBD patients over a 3-year period. The absent correlation between these markers and nigrostriatal dopaminergic dysfunction suggests that progressive gastrointestinal and cardiac dysfunction in iRBD is caused mainly by non-dopaminergic mechanisms., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
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11. Monitoring of Campylobacter jejuni in a chicken infection model by measuring specific volatile organic compounds and by qPCR.
- Author
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Hankel J, Gibson T, Skov J, Andersen KB, Dargatz M, Kappel A, Thiemann F, Curtis B, Chuppava B, and Visscher C
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- Animals, Chickens microbiology, Humans, Poultry, Campylobacter, Campylobacter Infections diagnosis, Campylobacter Infections microbiology, Campylobacter Infections veterinary, Campylobacter jejuni genetics, Poultry Diseases diagnosis, Poultry Diseases microbiology, Volatile Organic Compounds
- Abstract
Campylobacter is one of the leading bacterial foodborne pathogens worldwide. Poultry is the host species with this pathogen with the highest clinical impact. Flocks become colonised with Campylobacter, which leads to contamination of product entering the food-chain. Rapid and reliable Campylobacter detection methods could support controls to minimize the risks of contamination within the food-chain, which would easier enable the implementation of a logistical slaughter schedule or other control options. The present study evaluates current and emerging C. jejuni detection technologies on air samples in a unique study set-up of pre-defined C. jejuni prevalences. Both non-invasive detection technologies on air samples by subsequent measuring of volatile organic compounds (VOCs) or by qPCR detected the C. jejuni presence and could additionally distinguish between the number of present C. jejuni-positive birds in the study set-up. Nevertheless, electrostatic air samplers diagnosed fewer birds as C. jejuni-positive compared to the cultivation-based method. By measuring the VOCs, it was possible to detect the presence of two positive birds in the room. This apparent high sensitivity still needs to be verified in field studies. Techniques, such as these promising methods, that can facilitate C. jejuni surveillance in poultry flocks are desirable to reduce the risk of infection for humans., (© 2022. The Author(s).)
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- 2022
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12. Lateralization of word and face processing in developmental dyslexia and developmental prosopagnosia.
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Gerlach C, Kühn CD, Poulsen M, Andersen KB, Lissau CH, and Starrfelt R
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- Adult, Functional Laterality, Humans, Pattern Recognition, Visual, Visual Perception, Dyslexia, Facial Recognition, Prosopagnosia
- Abstract
In right-handed adults, face processing is lateralized to the right hemisphere and visual word processing to the left hemisphere. According to the many-to-many account (MTMA) of functional cerebral organization this lateralization pattern is partly dependent on the acquisition of literacy. Hence, the MTMA predicts that: (i) processing of both words and faces should show no or at least less lateralization in individuals with developmental dyslexia compared with controls, and (ii) lateralization in word processing should be normal in individuals with developmental prosopagnosia whereas lateralization in face processing should be absent. To test these hypotheses, 21 right-handed adults with developmental dyslexia and 21 right-handed adults with developmental prosopagnosia performed a divided visual field paradigm with delayed matching of faces, words and cars. Contrary to the predictions, we find that lateralization effects in face processing are within the normal range for both developmental dyslexics and prosopagnosics. Moreover, the group with developmental dyslexia showed right hemisphere lateralization for word processing. We argue that these findings are incompatible with the specific predictions of the MTMA., (Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2022
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13. Full NMR assignment, revised structure and biosynthetic analysis for the capsular polysaccharide from Streptococcus Pneumoniae serotype 15F.
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Li C, Andersen KB, Elverdal PL, Skovsted IC, Duus JØ, and Kjeldsen C
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- Carbohydrate Sequence, Bacterial Capsules chemistry, Bacterial Capsules metabolism, Serogroup, Carbohydrate Conformation, Streptococcus pneumoniae chemistry, Streptococcus pneumoniae metabolism, Magnetic Resonance Spectroscopy, Polysaccharides, Bacterial chemistry, Polysaccharides, Bacterial biosynthesis
- Abstract
Upon investigation of Streptococcus pneumoniae serotype 15F capsular polysaccharide (CPS), we discovered that it had a different phosphorylation substituent, namely glycerol-2-phosphate like the other serogroup 15 CPS rather than the originally reported 0.2 equivalent of phosphate or phosphocholine. Furthermore, we also determined the locations of the two previously unassigned O-acetyl groups present in the repeating unit of the 15F CPS, and carried out full NMR assignments of the 15F as well as 15A CPS. Lastly, a biosynthetic analysis of serotypes 15F and 15A was performed and used to make a prediction for the structure of the recently discovered serotype 15D., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2021
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14. Reduced Synaptic Density in Patients with Lewy Body Dementia: An [ 11 C]UCB-J PET Imaging Study.
- Author
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Andersen KB, Hansen AK, Damholdt MF, Horsager J, Skjaerbaek C, Gottrup H, Klit H, Schacht AC, Danielsen EH, Brooks DJ, and Borghammer P
- Subjects
- Humans, Positron-Emission Tomography, Alzheimer Disease, Cognitive Dysfunction, Lewy Body Disease diagnostic imaging, Parkinson Disease diagnostic imaging
- Abstract
Background: Patients with Parkinson's disease (PD) often develop dementia, but the underlying substrate is incompletely understood. Generalized synaptic degeneration may contribute to dysfunction and cognitive decline in Lewy body dementias, but in vivo evidence is lacking., Objective: The objective of this study was to assess the density of synapses in non-demented PD (nPD) subjects (N = 21), patients with PD-dementia or Dementia with Lewy bodies (DLB) (N = 13), and age-matched healthy controls (N = 15)., Method: Using in vivo PET imaging and the novel synaptic-vesicle-glycoprotein 2A (SV2A) radioligand [11C]UCB-J, SUVR-1 values were obtained for 12 pre-defined regions. Volumes-of-interest were defined on MRI T1 scans. Voxel-level between-group comparisons of [11C]UCB-J SUVR-1 were performed. All subjects underwent neuropsychological assessment. Correlations between [11C]UCB- J PET and domain-specific cognitive functioning were examined., Results: nPD patients only demonstrated significantly reduced SUVR-1 values in the substantia nigra (SN) compared to HC. DLB/PDD patients demonstrated reduced SUVR-1 values in SN and all cortical VOIs except for the hippocampus and amygdala. The voxel-based analysis supported the VOI results. Significant correlation was seen between middle frontal gyrus [11C]UCB-J SUVR-1 and performance on tests of executive function., Conclusion: Widespread cortical reduction of synaptic density was documented in a cohort of DLB/PDD subjects using in vivo [11C]UCB-J PET. Our study confirms previously reported synaptic loss in SN of nPD patients. [11C]UCB-J binding in selected cortical VOIs of the DLB/PDD patients correlated with their levels of cognitive function across relevant neuropsychological domains. These findings suggest that the loss of synaptic density contributes to cognitive impairment in nPD and DLB/PDD. © 2021 International Parkinson and Movement Disorder Society., (© 2021 International Parkinson and Movement Disorder Society.)
- Published
- 2021
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15. Vagus Nerve Cross-Sectional Area in Patients With Parkinson's Disease-An Ultrasound Case-Control Study.
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Horsager J, Walter U, Fedorova TD, Andersen KB, Skjærbæk C, Knudsen K, Okkels N, von Weitzel-Mudersbach P, Dyrskog SE, Bergholt B, and Borghammer P
- Abstract
Background: Vagal parasympathetic neurons are prone to degeneration in Parkinson's disease (PD). High-resolution ultrasound can precisely estimate the cross-sectional (CSA) area of peripheral nerves. Here, we tested the hypothesis that vagus CSA is reduced in PD. Methods: We included 56 healthy controls (HCs) and 63 patients with PD. Using a high-end ultrasound system equipped with a high-frequency transducer, five images were obtained of each nerve. The hypoechoic neuronal tissue was delineated offline with dedicated software and the CSA extracted. Results: In the initial PD vs. HC comparison, no statistically significant differences were observed in mean left vagus CSA (HC: 1.97 mm
2 , PD: 1.89 mm2 , P = 0.36) nor in mean right vagus CSA (HC: 2.37 mm2 , PD: 2.23 mm2 , P = 0.17). The right vagus CSA was significantly larger than the left vagus CSA in both groups ( P < 0.0001). Females were overrepresented in the HC group and presented with generally smaller vagus CSAs. Consequently, sex-adjusted CSA was significantly smaller for the right vagus nerve of the PD group ( P = 0.041), but not for the left. Conclusion: A small but significant reduction in sex-adjusted right vagus CSA was observed in patients with PD. The left vagus CSA was not significantly reduced in patients with PD. Ultrasound may not be a suitable method to detecting vagal axonal loss in individual patients., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Horsager, Walter, Fedorova, Andersen, Skjærbæk, Knudsen, Okkels, von Weitzel-Mudersbach, Dyrskog, Bergholt and Borghammer.)- Published
- 2021
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16. Generic multicriteria approach to determine the best precipitation agent for removal of biomacromolecules prior to non-targeted metabolic analysis.
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Knudsen SB, Nielsen NJ, Qvist J, Andersen KB, and Christensen JH
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- Acetonitriles chemistry, Algorithms, Chemical Precipitation, Methanol chemistry, Principal Component Analysis, Proteins chemistry, Solvents chemistry, Chromatography, High Pressure Liquid methods, Chromatography, Reverse-Phase methods, Metabolomics methods, Proteins isolation & purification
- Abstract
The removal of biomacromolecules from biofluids decreases the sample complexity and lower electrospray suppression effects. Furthermore, it can increase the analysis sensitivity, precision, and selectivity. Often removal approaches evaluate the model based on a single criterion, like protein removed or response of one of few specific metabolites. In this study, we used a multicriteria approach to test the effect of using the solvents methanol and acetonitrile (organic solvent precipitation), trichloroacetic acid (acidic precipitation) and ammonium sulphate (salting out) to remove biomacromolecules from a downstream recovery process from a bacillus fermentation. The downstream recovery process intermediates were analysed using reversed-phase ultra-high-pressure liquid chromatography with electrospray ionisation and high-resolution time-of-flight mass spectrometry detection. To evaluate the pre-treatment agents the following multicriteria was applied i) practical considerations, ii) total amino acid in the precipitated pellet, iii) putative identification of the molecules removed or created by the different treatments, iv) coherence between high quality extracted ion chromatograms (repeatability of DW-CODA) and v) replicate consistency from principal component analysis score values obtained by using the CHEMometric analysis of sections of Selected Ion Chromatograms (CHEMSIC) method. This study presents a generic workflow to find the best pre-treatment for removing bio-macromolecules from biofluids with a multicriteria approach. In our case, the best protein removal strategy for downstream recovery intermediates was acetonitrile precipitation. This method showed high precision, created few artefact peaks compared to simple sample dilution, and mainly removed small peptides., (Copyright © 2021 Elsevier B.V. All rights reserved.)
- Published
- 2021
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17. Face recognition in developmental dyslexia: evidence for dissociation between faces and words.
- Author
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Kühn CD, Gerlach C, Andersen KB, Poulsen M, and Starrfelt R
- Subjects
- Adolescent, Female, Humans, Male, Young Adult, Dyslexia physiopathology, Facial Recognition, Language, Recognition, Psychology
- Abstract
Developmental dyslexia is primarily a reading disorder, but recent studies have indicated that face processing problems may also be present. Using a case-series approach, we tested face recognition and visual word recognition in 24 high school students diagnosed with developmental dyslexia. Contrary to previous findings, no face recognition problems were found on the group-level. Rather, a significant classical dissociation with impaired word reading and normal face recognition was demonstrated on a group-level and for six individuals with developmental dyslexia. However, four individuals with dyslexia did show face recognition problems. Thus, while problems in face recognition can be present in developmental dyslexia, the dissociation strongly suggests that face recognition can also be preserved. Combined with previously reported dissociations between face and word recognition in developmental prosopagnosia, this constitutes a double dissociation.
- Published
- 2021
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18. Asymmetric Dopaminergic Dysfunction in Brain-First versus Body-First Parkinson's Disease Subtypes.
- Author
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Knudsen K, Fedorova TD, Horsager J, Andersen KB, Skjærbæk C, Berg D, Schaeffer E, Brooks DJ, Pavese N, Van Den Berge N, and Borghammer P
- Subjects
- Brain diagnostic imaging, Brain metabolism, Dopamine chemistry, Dopamine Plasma Membrane Transport Proteins chemistry, Dopamine Plasma Membrane Transport Proteins metabolism, Humans, Tomography, Emission-Computed, Single-Photon, alpha-Synuclein metabolism, Parkinson Disease diagnostic imaging, REM Sleep Behavior Disorder diagnostic imaging
- Abstract
Background: We have hypothesized that Parkinson's disease (PD) comprises two subtypes. Brain-first, where pathogenic α-synuclein initially forms unilaterally in one hemisphere leading to asymmetric nigrostriatal degeneration, and body-first with initial enteric pathology, which spreads through overlapping vagal innervation leading to more symmetric brainstem involvement and hence more symmetric nigrostriatal degeneration. Isolated REM sleep behaviour disorder has been identified as a strong marker of the body-first type., Objective: To analyse striatal asymmetry in [18F]FDOPA PET and [123I]FP-CIT DaT SPECT data from iRBD patients, de novo PD patients with RBD (PD+RBD) and de novo PD patients without RBD (PD-RBD). These groups were defined as prodromal body-first, de novo body-first, and de novo brain-first, respectively., Methods: We included [18F]FDOPA PET scans from 21 iRBD patients, 11 de novo PD+RBD, 22 de novo PD-RBD, and 18 controls subjects. Also, [123I]FP-CIT DaT SPECT data from iRBD and de novo PD patients with unknown RBD status from the PPPMI dataset was analysed. Lowest putamen specific binding ratio and putamen asymmetry index (AI) was defined., Results: Nigrostriatal degeneration was significantly more symmetric in patients with RBD versus patients without RBD or with unknown RBD status in both FDOPA (p = 0.001) and DaT SPECT (p = 0.001) datasets., Conclusion: iRBD subjects and de novo PD+RBD patients present with significantly more symmetric nigrostriatal dopaminergic degeneration compared to de novo PD-RBD patients. The results support the hypothesis that body-first PD is characterized by more symmetric distribution most likely due to more symmetric propagation of pathogenic α-synuclein compared to brain-first PD.
- Published
- 2021
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19. Brain-first versus body-first Parkinson's disease: a multimodal imaging case-control study.
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Horsager J, Andersen KB, Knudsen K, Skjærbæk C, Fedorova TD, Okkels N, Schaeffer E, Bonkat SK, Geday J, Otto M, Sommerauer M, Danielsen EH, Bech E, Kraft J, Munk OL, Hansen SD, Pavese N, Göder R, Brooks DJ, Berg D, and Borghammer P
- Subjects
- Aged, Aged, 80 and over, Case-Control Studies, Cross-Sectional Studies, Female, Humans, Male, Middle Aged, Multimodal Imaging methods, alpha-Synuclein metabolism, Brain diagnostic imaging, Brain metabolism, Magnetic Resonance Imaging methods, Parkinson Disease diagnostic imaging, Parkinson Disease metabolism, Positron Emission Tomography Computed Tomography methods
- Abstract
Parkinson's disease is characterized by the presence of abnormal, intraneuronal α-synuclein aggregates, which may propagate from cell-to-cell in a prion-like manner. However, it remains uncertain where the initial α-synuclein aggregates originate. We have hypothesized that Parkinson's disease comprises two subtypes. A brain-first (top-down) type, where α-synuclein pathology initially arises in the brain with secondary spreading to the peripheral autonomic nervous system; and a body-first (bottom-up) type, where the pathology originates in the enteric or peripheral autonomic nervous system and then spreads to the brain. We also hypothesized that isolated REM sleep behaviour disorder (iRBD) is a prodromal phenotype for the body-first type. Using multimodal imaging, we tested the hypothesis by quantifying neuronal dysfunction in structures corresponding to Braak stages I, II and III involvement in three distinct patient groups. We included 37 consecutive de novo patients with Parkinson's disease into this case-control PET study. Patients with Parkinson's disease were divided into 24 RBD-negative (PDRBD-) and 13 RBD-positive cases (PDRBD+) and a comparator group of 22 iRBD patients. We used 11C-donepezil PET/CT to assess cholinergic (parasympathetic) innervation, 123I-metaiodobenzylguanidine (MIBG) scintigraphy to measure cardiac sympathetic innervation, neuromelanin-sensitive MRI to measure the integrity of locus coeruleus pigmented neurons, and 18F-dihydroxyphenylalanine (FDOPA) PET to assess putaminal dopamine storage capacity. Colon volume and transit times were assessed with CT scans and radiopaque markers. Imaging data from the three groups were interrogated with ANOVA and Kruskal-Wallis tests corrected for multiple comparisons. The PDRBD- and PDRBD+ groups showed similar marked reductions in putaminal FDOPA-specific uptake, whereas two-thirds of iRBD patients had normal scans (P < 10-13, ANOVA). When compared to the PDRBD- patients, the PDRBD+ and iRBD patients showed reduced mean MIBG heart:mediastinum ratios (P < 10-5, ANOVA) and colon 11C-donepezil standard uptake values (P = 0.008, ANOVA). The PDRBD+ group trended towards a reduced mean MRI locus coeruleus: pons ratio compared to PDRBD- (P = 0.07, t-test). In comparison to the other groups, the PDRBD+ group also had enlarged colon volumes (P < 0.001, ANOVA) and delayed colonic transit times (P = 0.01, Kruskal-Wallis). The combined iRBD and PDRBD+ patient data were compatible with a body-first trajectory, characterized by initial loss of cardiac MIBG signal and 11C-colonic donepezil signal followed by loss of putaminal FDOPA uptake. In contrast, the PDRBD- data were compatible with a brain-first trajectory, characterized by primary loss of putaminal FDOPA uptake followed by a secondary loss of cardiac MIBG signal and 11C-donepezil signal. These findings support the existence of brain-first and body-first subtypes of Parkinson's disease., (© The Author(s) (2020). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
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20. Knee Injuries in Normal-Weight, Overweight, and Obese Runners: Does Body Mass Index Matter?
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Juhler C, Andersen KB, Nielsen RO, and Bertelsen ML
- Subjects
- Adult, Female, Humans, Leg Injuries complications, Male, Middle Aged, Risk Factors, Body Mass Index, Knee Injuries complications, Obesity complications, Overweight complications, Running injuries
- Abstract
Objective: To investigate whether the proportion of running-related knee injuries differed in normal-weight, overweight, and obese runners., Design: Comparative study., Methods: Data from 4 independent prospective studies were merged (2612 participants). The proportion of running-related knee injuries out of the total number of running-related injuries was calculated for normal-weight, overweight, and obese runners, respectively. The measure of association was absolute difference in proportion of running-related knee injuries with normal-weight runners as the reference group., Results: A total of 571 runners sustained a running-related injury (181 running-related knee injuries and 390 running-related injuries in other anatomical locations). The proportion of running-related knee injuries was 13% lower (95% confidence interval: -22%, -5%; P = .001) among overweight runners compared with normal-weight runners. Similarly, the proportion of running-related knee injuries was 12% lower (95% confidence interval: -23%, -1%; P = .042) among obese runners compared with normal-weight runners., Conclusion: Overweight and obese runners had a lower proportion of running-related knee injuries than normal-weight runners. J Orthop Sports Phys Ther 2020;50(7):397-401. doi:10.2519/jospt.2020.9233 .
- Published
- 2020
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21. Altered sensorimotor cortex noradrenergic function in idiopathic REM sleep behaviour disorder - A PET study.
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Andersen KB, Hansen AK, Sommerauer M, Fedorova TD, Knudsen K, Vang K, Van Den Berge N, Kinnerup M, Nahimi A, Pavese N, Brooks DJ, and Borghammer P
- Subjects
- Aged, Dihydroxyphenylalanine analogs & derivatives, Female, Humans, Male, Middle Aged, Morpholines, Parkinson Disease complications, Parkinson Disease diagnostic imaging, Positron-Emission Tomography, Putamen diagnostic imaging, REM Sleep Behavior Disorder diagnostic imaging, REM Sleep Behavior Disorder etiology, Sensorimotor Cortex diagnostic imaging, Thalamus diagnostic imaging, Norepinephrine metabolism, Parkinson Disease metabolism, Putamen metabolism, REM Sleep Behavior Disorder metabolism, Sensorimotor Cortex metabolism, Thalamus metabolism
- Abstract
Introduction: Noradrenergic denervation is thought to aggravate motor dysfunction in Parkinson's disease (PD). In a previous PET study with the norepinephrine transporter (NART) ligand
11 C-MeNER, we detected reduced NART binding in primary sensorimotor cortex (M1S1) of PD patients. Idiopathic rapid-eye-movement sleep behaviour disorder (iRBD) is a phenotype of prodromal PD. Using11 C-MeNER PET, we investigated whether iRBD patients showed similar NART binding reductions in M1S1 cortex as PD patients. Additionally, we investigated whether11 C-MeNER binding and loss of nigrostriatal dopamine storage capacity measured with18 F-DOPA PET were correlated., Methods: 17 iRBD patients, 16 PD patients with (PDRBD+ ) and 14 without RBD (PDRBD- ), and 25 control subjects underwent11 C-MeNER PET. iRBD patients also had18 F-DOPA PET. Volume-of-interest analyses and voxel-level statistical parametric mapping were performed., Results: Partial-volume corrected11 C-MeNER binding potential (BPND ) values in M1S1 differed across the groups (P = 0.022) with the iRBD and PDRBD+ groups showing significant reductions (controls vs. iRBD P = 0.007; control vs. PDRBD+ P = 0.008). Voxel-wise comparisons confirmed reductions of M1S111 C-MeNER binding in PD and iRBD patients. Significant correlation was seen between putaminal18 F-DOPA uptake and thalamic11 C-MeNER binding in iRBD patients (r2 = 0.343, P = 0.013)., Conclusions: This study found altered noradrenergic neurotransmission in the M1S1 cortex of iRBD patients. The observed reduction of M1S111 C-MeNER binding in iRBD may represent noradrenergic terminal degeneration or physiological down-regulation of NARTs in this prodromal phenotype of PD. The correlation between thalamic11 C-MeNER binding and putaminal18 F-DOPA binding suggests that these neurotransmitter systems degenerate in parallel in the iRBD phenotype of prodromal PD., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
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22. Permeability, strength and electrochemical studies on ceramic multilayers for solid-state electrochemical cells.
- Author
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Andersen KB, Charlas B, Stamate E, and Hansen KK
- Abstract
An electrochemical reactor can be used to purify flue gasses. Such a reactor can be a multilayer structure consisting of alternating layers of porous electrodes and electrolytes (a porous cell stack). In this work optimization of such a unit has been done by changing the pore former composition and the electrode powder pre-treatment. The effect on permeability, mechanical strength and electrochemical behavior was studied in this work. The effects were evaluated by measuring the pressure difference over the samples in relation to the flow through the sample, by the ball on ring method and by electrochemical impedance spectroscopy in air at temperatures between 300 and 450 °C. The resulting structures were also evaluated with scanning electron microscopy. The work showed a dependence on the pore former composition and electrode powder pre-treatment resulting in variations in porosity, strength and flow resistance. A higher porosity gives a lower backpressure. The electrochemical performance shows that both thickness and amount of pore former in the electrolyte is important, but almost no dependence of electrode composition on the polarization resistances within the tested compositions.
- Published
- 2017
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23. Improved Functional Performance in Geriatric Patients During Hospital Stay.
- Author
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Karlsen A, Loeb MR, Andersen KB, Joergensen KJ, Scheel FU, Turtumoeygard IF, Perez ALR, Kjaer M, and Beyer N
- Subjects
- Accelerometry instrumentation, Aged, Aged, 80 and over, Denmark, Female, Humans, Male, Prospective Studies, Exercise, Hand Strength, Hospitalization, Mobility Limitation
- Abstract
Objective: The aim of this work was to evaluate the time course of changes in strength and functional performance in elderly hospitalized medical patients., Design: This was a prospective observational study in elderly medical patients of age 65 years or older at a geriatric department.Measurements were obtained on days 2 to 4, day 5 to 8, and days 9 to 13. Functional performance was measured with De Morton Mobility Index (DEMMI) test and a 30-second chair stand test (30-s CST). Muscular strength was measured with handgrip strength. Activity level was determined with accelerometry (ActivPAL)., Results: Results in DEMMI and 30-s CST gradually improved (P < 0.05), whereas handgrip strength remained unchanged (P > 0.05). Larger functional improvements were observed in patients with "high" compared to "low" and "moderate" activity level (P < 0.05). Changes in DEMMI score correlated with changes in 30-s CST (P < 0.05); however, changes in DEMMI score and 30-s CST were more likely to occur in patients with a low versus high functional level, respectively., Conclusions: Functional performance of the lower extremities in geriatric patients improves moderately over the time of a hospital stay of less than 14 days, with larger improvements in patients with high activity level. The DEMMI test and the 30-s CST seem to be complementary to each other when evaluating functional changes in a geriatric hospital population., To Claim Cme Credits: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to (1) describe changes in mobility and muscle strength of geriatric patients during a hospital stay of less than 14 days, (2) understand the significance of physical activity during hospital admission in geriatric patients, and (3) discuss the potential limitations of measures for assessing mobility and lower extremity strength status and change during a hospital admission., Level: Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this activity for a maximum of 1.5 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.
- Published
- 2017
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24. The GPR139 reference agonists 1a and 7c, and tryptophan and phenylalanine share a common binding site.
- Author
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Nøhr AC, Jespers W, Shehata MA, Floryan L, Isberg V, Andersen KB, Åqvist J, Gutiérrez-de-Terán H, Bräuner-Osborne H, and Gloriam DE
- Subjects
- Binding Sites, DNA Mutational Analysis, Humans, Models, Molecular, Molecular Docking Simulation, Nerve Tissue Proteins genetics, Receptors, G-Protein-Coupled genetics, Nerve Tissue Proteins agonists, Nerve Tissue Proteins chemistry, Phenylalanine metabolism, Receptors, G-Protein-Coupled agonists, Receptors, G-Protein-Coupled chemistry, Tryptophan metabolism
- Abstract
GPR139 is an orphan G protein-coupled receptor expressed in the brain, in particular in the habenula, hypothalamus and striatum. It has therefore been suggested that GPR139 is a possible target for metabolic disorders and Parkinson's disease. Several surrogate agonist series have been published for GPR139. Two series published by Shi et al. and Dvorak et al. included agonists 1a and 7c respectively, with potencies in the ten-nanomolar range. Furthermore, Isberg et al. and Liu et al. have previously shown that tryptophan (Trp) and phenylalanine (Phe) can activate GPR139 in the hundred-micromolar range. In this study, we produced a mutagenesis-guided model of the GPR139 binding site to form a foundation for future structure-based ligand optimization. Receptor mutants studied in a Ca
2+ assay demonstrated that residues F1093×33 , H1875×43 , W2416×48 and N2717×38 , but not E1083×32 , are highly important for the activation of GPR139 as predicted by the receptor model. The initial ligand-receptor complex was optimized through free energy perturbation simulations, generating a refined GPR139 model in agreement with experimental data. In summary, the GPR139 reference surrogate agonists 1a and 7c, and the endogenous amino acids L-Trp and L-Phe share a common binding site, as demonstrated by mutagenesis, ligand docking and free energy calculations.- Published
- 2017
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25. The orphan G protein-coupled receptor GPR139 is activated by the peptides: Adrenocorticotropic hormone (ACTH), α-, and β-melanocyte stimulating hormone (α-MSH, and β-MSH), and the conserved core motif HFRW.
- Author
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Nøhr AC, Shehata MA, Hauser AS, Isberg V, Mokrosinski J, Andersen KB, Farooqi IS, Pedersen DS, Gloriam DE, and Bräuner-Osborne H
- Subjects
- Amino Acid Motifs, Animals, CHO Cells, Cricetulus, Melanocyte-Stimulating Hormones metabolism, Pro-Opiomelanocortin metabolism, Receptor, Melanocortin, Type 4 metabolism, Adrenocorticotropic Hormone metabolism, Melanocytes metabolism, Nerve Tissue Proteins metabolism, Receptors, G-Protein-Coupled metabolism, alpha-MSH metabolism, beta-MSH metabolism
- Abstract
GPR139 is an orphan G protein-coupled receptor that is expressed primarily in the brain. Not much is known regarding the function of GPR139. Recently we have shown that GPR139 is activated by the amino acids l-tryptophan and l-phenylalanine (EC
50 values of 220 μM and 320 μM, respectively), as well as di-peptides comprised of aromatic amino acids. This led us to hypothesize that GPR139 may be activated by peptides. Sequence alignment of the binding cavities of all class A GPCRs, revealed that the binding pocket of the melanocortin 4 receptor is similar to that of GPR139. Based on the chemogenomics principle "similar targets bind similar ligands", we tested three known endogenous melanocortin 4 receptor agonists; adrenocorticotropic hormone (ACTH) and α- and β-melanocyte stimulating hormone (α-MSH and β-MSH) on CHO-k1 cells stably expressing the human GPR139 in a Fluo-4 Ca2+ -assay. All three peptides, as well as their conserved core motif HFRW, were found to activate GPR139 in the low micromolar range. Moreover, we found that peptides consisting of nine or ten N-terminal residues of α-MSH activate GPR139 in the submicromolar range. α-MSH1-9 was found to correspond to the product of a predicted cleavage site in the pre-pro-protein pro-opiomelanocortin (POMC). Our results demonstrate that GPR139 is a peptide receptor, activated by ACTH, α-MSH, β-MSH, the conserved core motif HFRW as well as a potential endogenous peptide α-MSH1-9 . Further studies are needed to determine the functional relevance of GPR139 mediated signaling by these peptides., (Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.)- Published
- 2017
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26. Novel Agonist Bioisosteres and Common Structure-Activity Relationships for The Orphan G Protein-Coupled Receptor GPR139.
- Author
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Shehata MA, Nøhr AC, Lissa D, Bisig C, Isberg V, Andersen KB, Harpsøe K, Björkling F, Bräuner-Osborne H, and Gloriam DE
- Subjects
- Animals, CHO Cells, Cricetulus, Humans, Nerve Tissue Proteins genetics, Receptors, G-Protein-Coupled genetics, Structure-Activity Relationship, Hydrazines chemistry, Models, Chemical, Models, Molecular, Nerve Tissue Proteins agonists, Nerve Tissue Proteins chemistry, Receptors, G-Protein-Coupled agonists, Receptors, G-Protein-Coupled chemistry, Triazines chemistry
- Abstract
GPR139 is an orphan class A G protein-coupled receptor found mainly in the central nervous system. It has its highest expression levels in the hypothalamus and striatum, regions regulating metabolism and locomotion, respectively, and has therefore been suggested as a potential target for obesity and Parkinson's disease. The two aromatic amino acids
L -Trp andL -Phe have been proposed as putative endogenous agonists, and three structurally related benzohydrazide, glycine benzamide, and benzotriazine surrogate agonist series have been published. Herein, we assayed 158 new analogues selected from a pharmacophore model, and identified 12 new GPR139 agonists, containing previously untested bioisosteres. Furthermore, we present the first combined structure-activity relationships, and a refined pharmacophore model to serve as a rationale for future ligand identification and optimization.- Published
- 2016
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27. Fluidic system for long-term in vitro culturing and monitoring of organotypic brain slices.
- Author
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Bakmand T, Troels-Smith AR, Dimaki M, Nissen JD, Andersen KB, Sasso L, Waagepetersen HS, Gramsbergen JB, and Svendsen WE
- Subjects
- Animals, Mice, Microfluidics instrumentation, Hippocampus growth & development, Microfluidics methods, Tissue Culture Techniques methods
- Abstract
Brain slice preparations cultured in vitro have long been used as a simplified model for studying brain development, electrophysiology, neurodegeneration and neuroprotection. In this paper an open fluidic system developed for improved long term culturing of organotypic brain slices is presented. The positive effect of continuous flow of growth medium, and thus stability of the glucose concentration and waste removal, is simulated and compared to the effect of stagnant medium that is most often used in tissue culturing. Furthermore, placement of the tissue slices in the developed device was studied by numerical simulations in order to optimize the nutrient distribution. The device was tested by culturing transverse hippocampal slices from 7 days old NMRI mice for a duration of 14 days. The slices were inspected visually and the slices cultured in the fluidic system appeared to have preserved their structure better than the control slices cultured using the standard interface method.
- Published
- 2015
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28. High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up.
- Author
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Rathleff MS, Mølgaard CM, Fredberg U, Kaalund S, Andersen KB, Jensen TT, Aaskov S, and Olesen JL
- Subjects
- Adult, Female, Follow-Up Studies, Humans, Male, Middle Aged, Muscle Stretching Exercises, Pain Measurement, Treatment Outcome, Fasciitis, Plantar rehabilitation, Foot Orthoses, Resistance Training methods
- Abstract
The aim of this study was to investigate the effectiveness of shoe inserts and plantar fascia-specific stretching vs shoe inserts and high-load strength training in patients with plantar fasciitis. Forty-eight patients with ultrasonography-verified plantar fasciitis were randomized to shoe inserts and daily plantar-specific stretching (the stretch group) or shoe inserts and high-load progressive strength training (the strength group) performed every second day. High-load strength training consisted of unilateral heel raises with a towel inserted under the toes. Primary outcome was the foot function index (FFI) at 3 months. Additional follow-ups were performed at 1, 6, and 12 months. At the primary endpoint, at 3 months, the strength group had a FFI that was 29 points lower [95% confidence interval (CI): 6-52, P = 0.016] compared with the stretch group. At 1, 6, and 12 months, there were no differences between groups (P > 0.34). At 12 months, the FFI was 22 points (95% CI: 9-36) in the strength group and 16 points (95% CI: 0-32) in the stretch group. There were no differences in any of the secondary outcomes. A simple progressive exercise protocol, performed every second day, resulted in superior self-reported outcome after 3 months compared with plantar-specific stretching. High-load strength training may aid in a quicker reduction in pain and improvements in function., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2015
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29. Computer-aided discovery of aromatic l-α-amino acids as agonists of the orphan G protein-coupled receptor GPR139.
- Author
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Isberg V, Andersen KB, Bisig C, Dietz GP, Bräuner-Osborne H, and Gloriam DE
- Subjects
- Computer-Aided Design, HEK293 Cells, Humans, Models, Molecular, Nerve Tissue Proteins metabolism, Phenylalanine chemistry, Phenylalanine pharmacology, Receptors, G-Protein-Coupled metabolism, Tryptophan chemistry, Tryptophan pharmacology, Amino Acids, Aromatic chemistry, Amino Acids, Aromatic pharmacology, Dipeptides chemistry, Dipeptides pharmacology, Drug Design, Nerve Tissue Proteins agonists, Receptors, G-Protein-Coupled agonists
- Abstract
GPR139 is an orphan G protein-coupled receptor expressed mainly in the central nervous system. We developed a pharmacophore model based on known GPR139 surrogate agonists which led us to propose aromatic-containing dipeptides as potential ligands. Upon testing, the dipeptides demonstrated agonism in the Gq pathway. Next, in testing all 20 proteinogenic l-α-amino acids, L-tryptophan and l-phenylalanine were found to have EC50 values of 220 and 320 μM, respectively, making them the first putative endogenous agonists for GPR139.
- Published
- 2014
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30. Gas-particle partitioning of odorants in a pig house measured by thermal desorption GC/MS.
- Author
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Andersen KB, Glasius M, and Feilberg A
- Subjects
- Air Pollution, Indoor analysis, Animal Husbandry, Animals, Environmental Monitoring methods, Housing, Animal, Swine, Air Pollutants analysis, Odorants analysis
- Abstract
Odorous compounds identified in pig houses span a wide range of vapour pressures and may thus be present as volatile and semi-volatile compounds, but little is known about the partitioning between phases. In this study, the concentrations of 17 known odorants were measured in a pig house both in the gas phase and in particles. Particles were collected on PTFE coated glass fibre (GF) filters while gas phase compounds were collected using Tenax TA and Carbograph 5TD sorption tubes after the filtration. All samples were analysed using a thermal desorption gas chromatograph and mass spectrometer (TD-GC-MS). The effect of desorbing the filters at different temperatures (290, 200 and 100 °C) was investigated, and we found that a desorption temperature of 290 °C was optimal. Backup filters were placed behind the front particle sampling filter to account for adsorption of gas-phase compounds to the front filters (positive artefact). Adsorption of propanoic acid, butanoic acid and 4-methylphenol to GF filters and PTFE-coated GF filters was specifically investigated in the laboratory by measuring the air concentration with proton-transfer-reaction mass spectrometry. Both field and laboratory results show considerable adsorption of most compounds to filters, and the use of backup filters is necessary to account for this. Of the odorants investigated in this study, carboxylic acids (C4-C6) were the most abundant in the particles, which is ascribed to acid dissociation in the particles. The logarithm of the subcooled liquid vapour pressures, log p, plotted against the logarithm of estimated equilibrium gas-particle coefficients, log Kp, showed that the compounds were divided into two groups, polar and non-polar compounds, that showed linear trends with mr-values of -0.94 and -0.83 respectively. The study shows that it is possible to measure gas-particle partitioning by filters and TD-GC-MS. Only very low concentrations and low fractions of odorants were found in the particles measured in the pig house.
- Published
- 2014
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31. The retrovirus MA and PreTM proteins follow immature MLV cores.
- Author
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Andersen KB
- Subjects
- Animals, Cell Line, Protein Binding, Moloney murine leukemia virus physiology, Retroviridae Proteins, Oncogenic metabolism, Viral Envelope Proteins metabolism, Viral Matrix Proteins metabolism, Virus Assembly
- Abstract
We have used mild detergent to analyze the core of Moloney Murine Leukemia Virus (MoMLV) and core-like complexes in infected cells. The immature core consists of the Gag polyprotein (PrGag) and viral RNA (vRNA). It is known to be detergent-resistant, in contrast to the mature Gag core. The core matures by cleavage of PrGag into MA (matrix), p12, CA (capsid) and NC (nucleocapsid) protein. We found that mature Gag proteins were bound to the PrGag cores. The degree of binding differed widely. No (<0.1%) p12 bound, low amount of CA (3-5%), and higher amount of MA (13-20%) bound. Varying NC was bound (5-15%). NC could be released by RNase A in agreement with its binding to viral RNA. The TM (transmembrane) protein was also examined. A low amount of TM was bound to the PrGag core (approximately 5%), whereas a very high amount (65%) of the PreTM (TM with the cytoplasmic R peptide tail) bound. The binding in the PrGag core appears to occur by direct protein-protein interactions as only minute amounts of lipids including raft lipids were observed after detergent treatment., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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32. Dielectrophoretic manipulation and solubility of protein nanofibrils formed from crude crystallins.
- Author
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Domigan L, Andersen KB, Sasso L, Dimaki M, Svendsen WE, Gerrard JA, and Castillo-León J
- Subjects
- Amyloid metabolism, Animals, Crystallins metabolism, Electric Conductivity, Gadiformes, Lens, Crystalline chemistry, Microscopy, Electron, Transmission, Protein Stability, Solubility, Amyloid chemistry, Crystallins chemistry, Electrophoresis methods, Nanostructures chemistry
- Abstract
Protein nanofibrils and nanotubes are now widely accepted as having potential for use in the field of bionanotechnology. For this to be a feasible alternative to existing technologies, there is a need for a commercially viable source. Previous work has identified amyloid fibrils formed from crude crystallin proteins as such a source, since these fibrils can be produced in large quantities at a low cost. Applications include use of fibrils as templates for the formation of nanowires or as biosensing scaffolds. There remains a number of practical considerations, such as stability and the ability to control their arrangement. In this study, crude crystallin amyloid fibrils are shown to be stable in a range of biological and clean room solvents, with the fibril presence confirmed by transmission electron microscopy and the thioflavin T fluorescent assay. The fibrils were also immobilised between microelectrodes using dielectrophoresis, which enabled the recording of I-V curves for small numbers of fibrils. This investigation showed the fibrils to have low conductivity, with current values in the range of 10(-10) A recorded. This low conductivity could be increased through modification, or alternately, the fibrils could be used unmodified for applications where they can act as templates or high surface area nanoscaffolds., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2013
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33. Minimisation of artefact formation of dimethyl disulphide during sampling and analysis of methanethiol in air using solid sorbent materials.
- Author
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Andersen KB, Hansen MJ, and Feilberg A
- Subjects
- Adsorption, Air Pollutants chemistry, Environmental Monitoring, Solid Phase Extraction instrumentation, Sulfhydryl Compounds chemistry, Temperature, Air Pollutants isolation & purification, Disulfides chemistry, Solid Phase Extraction methods, Sulfhydryl Compounds isolation & purification
- Abstract
Methanethiol (MT) is a potent odorant that can be difficult to measure due to its high volatility and reactivity; it easily reacts to form dimethyl disulphide (DMDS) during sampling and/or analysis. This paper focuses on finding an optimal method for sampling and measuring MT with minimum artefact formation using sorbent materials and a thermal desorption-gas chromatography-mass spectrometry method (TD-GC-MS). Experiments were conducted to identify suitable sorbent materials and tubes for analysis. Breakthrough, desorption rate, the effects of storage and desorption temperatures were investigated and different drying methods were established with respect to quantitative sampling and formation of DMDS. Proton-transfer-reaction mass spectrometry (PTR-MS) was used in the development of the method and was an especially useful tool for determination of breakthrough. The results show that glass tubes packed with silica gel for pre-concentration of MT before analysis with TD-GC-MS give the best results. In addition, a combination of Tenax TA and carbonised molecular sieve or Tenax TA cooled to ≤0°C gives acceptable results. 80°C was found to be the optimal desorption temperature. For all the sampling methods tested, storage conditions were observed to be very critical for transformation of MT. Room temperature storage should be limited to few minutes and, in general, tubes should be kept at 0°C or lower during storage., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
34. Use of non-thermal plasma and UV-light for removal of odour from sludge treatment.
- Author
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Andersen KB, Feilberg A, and Beukes JA
- Subjects
- Ultraviolet Rays, Gas Chromatography-Mass Spectrometry, Odorants prevention & control, Sewage, Waste Disposal, Fluid methods
- Abstract
Non-thermal plasma (NTP) systems can be used for abatement of odour nuisances. Odour reductions are achieved by radical-initiated oxidation and dust collection in the plasma reactor. For some emissions a sequence of NTP followed by UV-light can improve the odour reduction further. This study was conducted to evaluate the efficiency of NTP technology combined with UV-light towards odour emissions from sludge treatment. Air from a pilot sludge dryer was treated with a pilot NTP and a UV unit. The effect of using an acid scrubber upstream the NTP system was also tested. Thermal desorption gas chromatography and mass spectrometry (TD-GC/MS) was used to analyse samples taken from the inlet and the outlet of the NTP system. The TD-GC/MS used was also equipped with a sniffing port that made it possible to record odour-active compounds eluting from the column. Relative amounts of odour-active compounds in the inlet and the outlet flow from the NTP system were compared. Bag samples from inlet and outlet were also separately analysed by an external lab and by two operators using a one-man olfactometer, a modified NasalRanger(TM). These results indicated a significant odour removal efficiency of 70-90% depending on the settings and combinations of abatement equipment.
- Published
- 2012
- Full Text
- View/download PDF
35. Stability of diphenylalanine peptide nanotubes in solution.
- Author
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Andersen KB, Castillo-Leon J, Hedström M, and Svendsen WE
- Subjects
- Dipeptides, Macromolecular Substances chemistry, Materials Testing, Molecular Conformation, Particle Size, Phenylalanine chemistry, Solutions, Surface Properties, Nanotubes chemistry, Nanotubes ultrastructure, Phenylalanine analogs & derivatives
- Abstract
Over the last couple of years, self-organizing nanotubes based on the dipeptide diphenylalanine have received much attention, mainly as possible building blocks for the next generation of biosensors and as drug delivery systems. One of the main reasons for this large interest is that these peptide nanotubes are believed to be very stable both thermally and chemically. Previously, the chemical and thermal stability of self-organizing structures has been investigated after the evaporation of the solvent. However, it was recently discovered that the stability of the structures differed significantly when the tubes were in solution. It has been shown that, in solution, the peptide nanotubes can easily be dissolved in several solvents including water. It is therefore of critical importance that the stability of the nanotubes in solution and not after solvent evaporation be investigated prior to applications in which the nanotube will be submerged in liquid. The present article reports results demonstrating the instability and suggests a possible approach to a stabilization procedure, which drastically improves the stability of the formed structures. The results presented herein provide new information regarding the stability of self-organizing diphenylalanine nanotubes in solution.
- Published
- 2011
- Full Text
- View/download PDF
36. Role of electrostatic repulsion on colloidal stability of Bacillus halmapalus alpha-amylase.
- Author
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Olsen SN, Andersen KB, Randolph TW, Carpenter JF, and Westh P
- Subjects
- Spectrophotometry, Infrared, Bacillus enzymology, Colloids, Static Electricity, alpha-Amylases metabolism
- Abstract
The colloidal stability of charged particles in suspension is often controlled by electrostatic repulsion, which can be rationalized in a semi-quantitative way by the DLVO theory. In the current study, we investigate this approach towards understanding irreversible protein aggregation, using Bacillus halmapalus alpha-amylase (BHA) as a model protein. Repulsive forces between partly unfolded monomers were shown to strongly affect aggregation. Adding salt, increasing valence of counter ions or decreasing pH in the direction of pI resulted in a shift in the rate-limiting step from association to unfolding as evidenced by a change in aggregation kinetics from second to first-order in protein concentration. Charge screening effects by salts resulted in increased average size of protein aggregates but only moderately affected the secondary structure of protein within the aggregates. Salt and pH effects could be explained within the DLVO framework, indicating that partially unfolded BHA monomers can be modelled realistically as colloids with a random charge distribution.
- Published
- 2009
- Full Text
- View/download PDF
37. A generalized theoretical model for "continuous particle separation in a microchannel having asymmetrically arranged multiple branches".
- Author
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Andersen KB, Levinsen S, Svendsen WE, and Okkels F
- Abstract
In this article we present a generalized theoretical model for the continuous separation of particles using the pinched flow fractionation method. So far the theoretical models have not been able to predict the separation of particles without the use of correction factors. In this article we present a model which is capable of predicting the separation from first principles. Furthermore we comment on the importance of the incorporation of the finite height of the micro fluidic channels in the models describing the system behavior. We compare our model with the experiment obtained by Seki et al. (J. Takagi, M. Yamada, M. Yasuda and M. Seki, Lab Chip, 2005, 5, 778-784).
- Published
- 2009
- Full Text
- View/download PDF
38. Murine leukemia virus transmembrane protein R-peptide is found in small virus core-like complexes in cells.
- Author
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Andersen KB, Diep HA, and Zedeler A
- Subjects
- Animals, Centrifugation methods, Leukemia Virus, Murine genetics, Mice, NIH 3T3 Cells, Octoxynol, Retroviridae Proteins, Oncogenic chemistry, Retroviridae Proteins, Oncogenic genetics, Viral Envelope Proteins chemistry, Viral Envelope Proteins genetics, Viral Envelope Proteins metabolism, Virion chemistry, Leukemia Virus, Murine metabolism, Retroviridae Proteins, Oncogenic metabolism, Viral Matrix Proteins metabolism, Virion metabolism, Virus Assembly
- Abstract
The core of the retrovirus Murine leukemia virus (MLV) consists of the Gag precursor protein and viral RNA. It assembles at the cytoplasmic face of the cell membrane where, by an unclear mechanism, it collects viral envelope proteins embedded in the cell membrane and buds off. The C-terminal half of the short cytoplasmic tail of the envelope transmembrane protein (TM) is cleaved off to yield R-peptide and fusion-active TM. In Moloney MLV particles, R-peptide was found to bind to core particles. In cells, R-peptide and low amounts of uncleaved TM were found to be associated with small core-like complexes, i.e. mild detergent-insoluble, Gag-containing complexes with a density of 1.23 g ml(-1) and a size of 150-200 S. Our results suggest that TM associates with the assembling core particle through the R-peptide before budding and that this is the mechanism by which the budding virus acquires the envelope proteins.
- Published
- 2006
- Full Text
- View/download PDF
39. [Esophageal resections in Denmark 1997-2000].
- Author
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Jensen LS, Parvaiz I, Utzon J, Andersen KB, Olsen PS, and Kehlet H
- Subjects
- Adult, Clinical Competence, Denmark epidemiology, Hospital Mortality, Humans, Length of Stay statistics & numerical data, Patient Readmission statistics & numerical data, Postoperative Complications mortality, Quality Indicators, Health Care, Reoperation statistics & numerical data, Utilization Review, Esophageal Diseases surgery, Esophagectomy standards, Esophagectomy statistics & numerical data, Esophagus surgery, Quality Assurance, Health Care
- Abstract
Introduction: We evaluated the changes in Denmark since the 1980s in the incidence, management and outcome of oesophageal resections., Material and Methods: The national patient hospital register and discharge information from the hospitals were examined for the number of oesophageal resections performed, the length of the postoperative stay, readmission, postoperative complications, and hospital mortality in the period 1/1-1997 to 30/6-2000., Results: Twenty-six departments in 18 hospitals performed 476 resections. Five hospitals accounted for 92% of all the resections performed. In three hospitals, the resections were carried out in three different departments and 18 departments performed fewer than four resections per year. The postoperative stay was 19.2 days. The frequency of surgical complications was 19% and hospital mortality was 10.7%., Discussion: The small number of oesophageal resections performed in many departments in Denmark is not in accordance with international recommendations, which say that the operation should be performed in high volume centres by experienced oesophageal surgeons, including thoracic surgeons, surgical gastroenterologists, and thoracic anaesthesiologists. On these results, it is recommended that the operation is performed in few centres and by few surgeons in multidisciplinary teams.
- Published
- 2002
40. A differential vapor-pressure equipment for investigations of biopolymer interactions.
- Author
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Andersen KB, Koga Y, and Westh P
- Subjects
- 1-Butanol chemistry, Adsorption, Animals, Biophysical Phenomena, Biophysics, Cattle, Cyclodextrins chemistry, Equipment Design, In Vitro Techniques, Liposomes, Muramidase chemistry, Pressure, Protein Binding, Serum Albumin, Bovine chemistry, Solvents, Temperature, Thermodynamics, Water, Biopolymers chemistry, Manometry instrumentation
- Abstract
The design and performance of an equipment for the measurement of vapor pressures over liquid or solid samples is presented. The equilibrium pressure difference, DeltaP, between a sample and a reference of known vapor pressure is recorded as a function of composition and/or temperature. Through the use of high-accuracy capacitance manometers and a leak-tight system of stainless steel pipes, below-sealed valves and metal-gasket fittings, DeltaP can be measured with a resolution of about 0.5 micro bar (0.05 Pa) in some applications. This sensitivity level, along with other features of the equipment, particularly a "gas-phase titration" routine for changing the cell composition, makes it effective for the investigations of several types of biopolymer interactions. These include isothermal studies of net affinities such as the adsorption of water to proteins or membranes, the preferential interaction of biopolymers with the components of a mixed solvent, the partitioning of solutes between a membrane and the aqueous bulk and the weak, specific binding of ligands to macromolecules. Furthermore, a temperature-scanning mode allows real-time elucidation of such interactions at thermally induced conformational changes in biopolymers. Selected examples of these applications are presented and discussed.
- Published
- 2002
- Full Text
- View/download PDF
41. [Evaluation of surgical interventions in Denmark].
- Author
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Utzon J, Olsen PS, Bay-Nielsen M, Andersen KB, Christensen B, Endahl LA, Krarup T, Lucht U, Ottesen BS, Schroeder TV, and Kehlet H
- Subjects
- Clinical Competence, Denmark, Humans, Quality Assurance, Health Care, Surgical Procedures, Operative adverse effects, Surgical Procedures, Operative methods, Surgical Procedures, Operative statistics & numerical data, Surgical Procedures, Operative standards
- Published
- 2001
42. Rational selection of antisense oligonucleotide sequences.
- Author
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Smith L, Andersen KB, Hovgaard L, and Jaroszewski JW
- Subjects
- Base Sequence, Drug Design, Models, Molecular, Molecular Sequence Data, Nucleic Acid Conformation, Oligodeoxyribonucleotides, Antisense chemical synthesis, Oligodeoxyribonucleotides, Antisense pharmacology, Oligonucleotides, Antisense chemical synthesis, Oligonucleotides, Antisense pharmacology, RNA, Messenger chemistry, RNA, Messenger drug effects, Ribonuclease H metabolism, Structure-Activity Relationship, Oligodeoxyribonucleotides, Antisense chemistry, Oligonucleotides, Antisense chemistry, RNA, Messenger genetics
- Abstract
The purpose of this review is to identify rational selection procedures for the identification of optimal antisense oligonucleotide sequences. The review is firstly focused on how to find optimal hybridization sites, and secondly on how to select sequences that bind to structured RNA. The methods reviewed range from the more empirical testing of large numbers of mRNA complementary sequences to the more systematic techniques, i.e. RNase H mapping, use of combinatorial arrays and prediction of secondary structure of mRNA by computational methods. Structures that bind to structured RNA, i.e. aptastrucs and tethered oligonucleotide probes, and foldback triplex-forming oligonucleotides are also discussed. Relating to selection of antisense sequences by aid of computational analysis, valuable www addresses are given along with examples of folded structures of mRNA.
- Published
- 2000
- Full Text
- View/download PDF
43. Infrared and Raman spectroscopic investigations of the Nb(V) fluoro and oxofluoro complexes in the LiF-NaF-KF eutectic melt with development of a diamond IR cell.
- Author
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Andersen KB, Christensen E, Berg RW, Bjerrum NJ, and von Barner JH
- Abstract
A vacuum-tight cell for infrared spectroscopic investigations of extremely corrosive melts, e.g., molten fluorides, has been constructed and tested up to 750 degrees C. The cell has a gold-lined sample chamber and a diamond window transparent for the infrared light. It can be furnished with a gold piston that enables the recording of short-path-length FTIR spectra of liquid samples. Solutions of Nb(V) in LiF-NaF-KF eutectic (FLINAK) with and without oxide additions have been investigated by FTIR and Raman spectroscopy. The presence of NbF7(2-), NbOF5(2-), and NbO2F4(3-) complexes was established in the molten state at 600 degrees C. After solidification NbF7(2-) was still the only Nb(V) all-fluoro complex present. Three oxofluoro complexes, NbOF6(3-), NbOF5(2-), and NbO2F4(3-), have been identified in the solid state. Typical frequency regions for the different complexes are established. Finally, it was shown that K2NbF7 can be used as an indicator to determine the oxide content of the sample melts.
- Published
- 2000
- Full Text
- View/download PDF
44. [Screening for lung cancer].
- Author
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Andersen KB and Dirksen A
- Subjects
- Denmark, Humans, Lung Neoplasms diagnosis, Lung Neoplasms diagnostic imaging, Tomography, X-Ray Computed, Lung Neoplasms prevention & control, Mass Screening
- Published
- 2000
45. Palmitoylation of the intracytoplasmic R peptide of the transmembrane envelope protein in Moloney murine leukemia virus.
- Author
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Olsen KE and Andersen KB
- Subjects
- 3T3 Cells, Animals, Cytoplasm metabolism, Electrophoresis, Gel, Two-Dimensional, Electrophoresis, Polyacrylamide Gel methods, Immunoblotting, Mice, Molecular Weight, Peptides chemical synthesis, Retroviridae Proteins, Oncogenic chemistry, Subcellular Fractions, Viral Envelope Proteins chemistry, Viral Envelope Proteins metabolism, Viral Matrix Proteins chemistry, Moloney murine leukemia virus metabolism, Palmitic Acid metabolism, Retroviridae Proteins, Oncogenic metabolism, Viral Matrix Proteins metabolism
- Abstract
Previously it was reported that the 16-amino-acid (aa) C-terminal cytoplasmic tail of Moloney murine leukemia virus (MoMLV) transmembrane protein Pr15E is cleaved off during virus synthesis, yielding the mature, fusion active transmembrane protein p15E and the 16-aa peptide (R peptide or p2E). It remains to be elucidated how the R peptide impairs fusion activity of the uncleaved Pr15E. The R peptide from MoMLV was analyzed by Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunostained with antiserum against the synthetic 16-aa R peptide. The R peptide resolved with an apparent molecular mass of 7 kDa and not the 4 kDa seen with the corresponding synthetic peptide. The 7-kDa R peptide was found to be membrane bound in MoMLV-infected NIH 3T3 cells, showing that cleavage of the 7-kDa R-peptide tail must occur before or during budding of progeny virions, in which only small amounts of the 7-kDa R peptide were found. The 7-kDa R peptide was palmitoylated since it could be labeled with [(3)H]palmitic acid, which explains its membrane association, slower migration on gels, and high sensitivity in immunoblotting. The present results are in contrast to previous findings showing equimolar amounts of R peptide and p15E in virions. The discrepancy, however, can be explained by the presence of nonpalmitoylated R peptide in virions, which were poorly detected by immunoblotting. A mechanistic model is proposed. The uncleaved R peptide can, due to its lipid modification, control the conformation of the ectodomain of the transmembrane protein and thereby govern membrane fusion.
- Published
- 1999
- Full Text
- View/download PDF
46. [Thoracic surgery in children].
- Author
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Ainsworth AP and Andersen KB
- Subjects
- Adolescent, Age Factors, Child, Child, Preschool, Denmark, Female, Humans, Infant, Infant, Newborn, Male, Retrospective Studies, Thoracic Surgical Procedures methods, Thoracic Surgical Procedures mortality, Thoracic Surgical Procedures statistics & numerical data
- Abstract
In order to study non-cardiac thoracic surgery in children we reviewed the files of all children under 16 years, who had surgery at the Department of Thoracic and Cardiovascular Surgery, Odense University Hospital from 1987 to 1996. Thirty-three children had chest tube insertion because of neonatal pneumothorax. Twelve of these died within five days after birth. Fifty-five children had surgery for primary intrathoracic diseases. Congenital pulmonary malformations were most common in the youngest children. Traumatic diseases were most common in the oldest. No immediate postoperative deaths occurred, but seven children were dead at the follow-up. Thirty-eight had surgery for involvement of the thoracic organs secondary to other often malignant diseases. Eleven of these were dead at the follow-up. It is concluded, that thoracic surgery is required for a number of diseases in children and is well tolerated. However, severe primary diseases lead to an increased mortality.
- Published
- 1999
47. The Electronic Structure of Carcinogenic Dibenzopyrenes: Linear Dichroism, Fluorescence Polarization Spectroscopy and Quantum Mechanical Calculations.
- Author
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Andersen KB, Waluk J, and Thulstrup EW
- Abstract
Abstract- In studies of polycyclic aromatic hydrocarbon carcinogenicity three dibenzopyrenes have been named as the strongest mutagens together with the frequently studied benzo[a]pyrene. A detailed study of the electronic structure of one of the three compounds, dibenzo [a, i] pyrene, was performed several years ago. Here we present a similar study of the two remaining compounds, dibenzo [a, h] pyrene and dibenzo [a, e] pyrene. The studies include electronic linear dichroism spectra, fluorescence polarization spectra and quantum mechanical calculations for both molecules, as well as vibrational linear dichroism spectra for the former of the two.
- Published
- 1999
- Full Text
- View/download PDF
48. Fusion between uninfected cells in retrovirus-induced fusion-from-within.
- Author
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Andersen KB and Olsen KE
- Subjects
- 3T3 Cells, Animals, Cells, Cultured, Mice, Cell Fusion, Retroviridae physiology
- Abstract
We previously examined Moloney murine leukemia virus-induced fusion-from-within (FFWI) and fusion-from-without (FFWO) of SC-1 mouse cells. FFWI and FFWO can be distinguished by their stimulation by ionophores and polycations, respectively. FFWI is caused by infected cells. Normally, fusion between an infected cell and uninfected cells (heterofusions) is described, but we have surprisingly found that the infected cells also caused homofusion between uninfected cells in their vicinity (named neighbor homofusions). It was shown that neighbor homofusions were not induced by free virus particles (by FFWO). Transfectants expressing envelope proteins only induced heterofusions, indicating that virus production is necessary for the formation of neighbor homofusions. Both plasma membrane fragments and easily removable material from the surface of infected cells were able to induce fusion with the same stimulation pattern as FFWI and neighbor homofusion. These materials, especially the latter, have properties in common with virions, and it is discussed whether immature virions are involved in the formation of the neighbor homofusions.
- Published
- 1998
- Full Text
- View/download PDF
49. [Surgical treatment of cancer of the esophagus and cardia].
- Author
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Jensen BM and Andersen KB
- Subjects
- Adult, Aged, Carcinoma pathology, Cardia pathology, Esophageal Neoplasms pathology, Esophagectomy adverse effects, Esophagectomy mortality, Female, Gastrectomy adverse effects, Gastrectomy mortality, Humans, Male, Middle Aged, Postoperative Complications mortality, Prognosis, Retrospective Studies, Stomach Neoplasms pathology, Carcinoma surgery, Esophageal Neoplasms surgery, Stomach Neoplasms surgery
- Abstract
The purpose of the present study was to evaluate the results following surgical resection for cancer of the gastro-oesophageal junction. From 1. january 1988 to 1. april 1996 radical resection was intended in 107 patients at the Department of Thoracic and Cardiovascular Surgery at Odense University Hospital. Resection was possible in 75 patients. The operative mortality was 6.7% insufficiency of the gastro-oesophageal anastomosis was found in 6.7%. Five year survival was 24.1%. However in 52 patients where the resection was found to be radical the five-year survival was 35.3%. The results show that oesophago-gastrectomy could be performed with low mortality and morbidity. Long term survival is still low. To improve the results efforts should be directed toward earlier diagnosis, better selection and minimising post-operative complications.
- Published
- 1998
50. K+ ionophores stimulate retrovirus-induced fusion-from-within.
- Author
-
Andersen KB
- Subjects
- 3T3 Cells, Amphotericin B pharmacology, Animals, Cell Line, Gene Products, env metabolism, Humans, Kinetics, Mice, Ionophores pharmacology, Membrane Fusion, Moloney murine leukemia virus metabolism, Potassium pharmacology
- Abstract
Fusion-from-without (FFWO) and fusion-from-within (FFWI) for Moloney MLV in SC-1 cells were selectively stimulated by the polycation polybrene and the ionophore amphotericin B, which can be used to discriminate between the two fusion types. FFWI was stimulated by a number of different K+ ionophores. The stimulation occurred within few hours, did not require protein synthesis, and depended on the uninfected cell type, which suggests that FFWI is stimulated by a permutation of the K+ gradient of the uninfected cell. Plasma membrane vesicles from infected cells could also stimulate fusion with the same stimulation pattern as FFWI.
- Published
- 1998
- Full Text
- View/download PDF
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