96 results on '"J. Asp"'
Search Results
2. Effects of Unilateral High Frequency Stimulation of the Subthalamic Nucleus on Risk-avoidant Behavior in a Partial 6-hydroxydopamine Model of Parkinson's Disease
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Sydney G. Hillan, Anders J. Asp, Leena B. Pramanik, Aarushi A. Mukerjee, Carter B. Mulder, Wendy D. Lujan, Jodi L. Silvernail, Su-Youne Chang, Suelen L. Boschen, and J. Luis Lujan
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deep brain stimulation ,subthalamic nucleus ,risk-avoidance ,6-hydroxydopamine ,parkinson's disease ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Background: Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a well-established treatment for the motor symptoms of Parkinson’s disease (PD). While PD is primarily characterized by motor symptoms such as tremor, rigidity, and bradykinesia, it also involves a range of non-motor symptoms, and anxiety is one of the most common. The relationship between PD and anxiety is complex and can be a result of both pathological neural changes and the psychological and emotional impacts of living with a chronic progressive condition. Managing anxiety in PD is critical for improving the patients’ quality of life. However, patients undergoing STN DBS can occasionally experience increased anxiety. Methods: This study investigates changes in risk-avoidant behavior following STN DBS in a pre-motor animal model of PD under chronic and acute unilateral high frequency stimulation. Results: No significant changes in risk-avoidant behaviors were observed in rats who underwent STN DBS compared with sham stimulation controls. Chronic stimulation prevented sensitization in the elevated zero maze. Conclusions: These results suggest that unilateral stimulation of the STN may have minimal effects on risk-avoidant behaviors in PD. However, additional research is required to fully understand the mechanisms responsible for changes in anxiety during STN DBS for PD.
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- 2024
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3. A quadruple dissociation of reward-related behaviour in mice across excitatory inputs to the nucleus accumbens shell
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Erin B. Lind, Brian M. Sweis, Anders J. Asp, Manuel Esguerra, Keelia A. Silvis, A. David Redish, and Mark J. Thomas
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Biology (General) ,QH301-705.5 - Abstract
An optogenetic, spatial self-stimulation task in mice reveals how information carried by distinct inputs to the nucleus accumbens shell is potentially integrated to drive behavioural responses.
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- 2023
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4. Targeted neuroplasticity in spatiotemporally patterned invasive neuromodulation therapies for improving clinical outcomes.
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Anders J. Asp, Yaswanth Chintaluru, Sydney Hillan, and Jose-Luis Poza-Luján
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- 2023
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5. Combining Celiac and Hepatic Vagus Nerve Neuromodulation Reverses Glucose Intolerance and Improves Glycemic Control in Pre- and Overt-Type 2 Diabetes Mellitus
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Jonathan J. Waataja, Anders J. Asp, and Charles J. Billington
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type 2 diabetes ,vagus nerve ,vagus nerve stimulation ,bioelectronics ,neuromodulation ,neurological disorders ,Biology (General) ,QH301-705.5 - Abstract
Neurological disorders and type 2 diabetes mellitus (T2DM) are deeply intertwined. For example, autonomic neuropathy contributes to the development of T2DM and continued unmanaged T2DM causes further progression of nerve damage. Increasing glycemic control has been shown to prevent the onset and progression of diabetic autonomic neuropathies. Neuromodulation consisting of combined stimulation of celiac vagal fibers innervating the pancreas with concurrent electrical blockade of neuronal hepatic vagal fibers innervating the liver has been shown to increase glycemic control in animal models of T2DM. The present study demonstrated that the neuromodulation reversed glucose intolerance in alloxan-treated swine in both pre- and overt stages of T2DM. This was demonstrated by improved performance on oral glucose tolerance tests (OGTTs), as assessed by area under the curve (AUC). In prediabetic swine (fasting plasma glucose (FPG) range: 101–119 mg/dL) the median AUC decreased from 31.9 AUs (IQR = 28.6, 35.5) to 15.9 AUs (IQR = 15.1, 18.3) p = 0.004. In diabetic swine (FPG range: 133–207 mg/dL) the median AUC decreased from 54.2 AUs (IQR = 41.5, 56.6) to 16.0 AUs (IQR = 15.4, 21.5) p = 0.003. This neuromodulation technique may offer a new treatment for T2DM and reverse glycemic dysregulation at multiple states of T2DM involved in diabetic neuropathy including at its development and during progression.
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- 2023
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6. Multifunctional system for observing, measuring and analyzing stimulation-evoked neurochemical signaling.
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Christopher J. Kimble, Joshua B. Boesche, Diane R. Eaker, Kenneth R. Kressin, Malcolm B. McIntosh, Jose-Luis Poza-Luján, James K. Trevathan, Seungleal Paek, and Anders J. Asp
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- 2017
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7. An ultra-low frequency spike timing dependent plasticity-based approach for treating alcohol use disorder
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Suelen Lucio Boschen, J. Luis Lujan, and Anders J. Asp
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business.industry ,Alcohol ,Stimulation ,Striatum ,Alcohol use disorder ,Optogenetics ,Bioinformatics ,Medium spiny neuron ,medicine.disease ,chemistry.chemical_compound ,chemistry ,Dopamine receptor ,medicine ,business ,Hypoactivity - Abstract
Alcohol use disorder (AUD) is a chronic relapsing brain disorder characterized by an impaired ability to stop or control alcohol consumption despite adverse social, occupational, or health consequences. AUD affects nearly one-third of adults at some point during their lives, with an associated cost of approximately $249 billion annually in the U.S. alone. The effects of alcohol consumption are expected to increase significantly during the COVID-19 pandemic, with alcohol sales increased by approximately 54%, potentially exacerbating health concerns and risk-taking behaviors. Unfortunately, existing pharmacological and behavioral therapies for AUD have historically been associated with poor success rates, with approximately 40% of individuals relapsing within three years of treatment.Pre-clinical studies have shown that chronic alcohol consumption leads to significant changes in synaptic function within the dorsal medial striatum (DMS), one of the brain regions associated with AUD and responsible for mediating goal-directed behavior. Specifically, chronic alcohol consumption has been associated with hyperactivity of dopamine receptor 1 (D1) medium spiny neurons (MSN) and hypoactivity of dopamine receptor 2 (D1) MSNs within the DMS. Optogenetic, chemogenetic, and transgenic approaches have demonstrated that reducing the D1/D2 MSN signaling imbalance decreases alcohol self-administration in rodent models of AUD. However, these approaches cannot be studied clinically at this time.Here, we present an electrical stimulation alternative that uses ultra-low (
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- 2021
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8. Integral methods for automatic quantification of fast-scan-cyclic-voltammetry detected neurotransmitters
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Anders J. Asp, James K. Trevathan, Leonardo X. Espín, J. Luis Lujan, and Kip A. Ludwig
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Adenosine ,Computer science ,Dopamine ,Glycobiology ,Amperometry ,02 engineering and technology ,01 natural sciences ,Biochemistry ,Norepinephrine ,Catecholamines ,Medicine and Health Sciences ,Amines ,Neurotransmitter Agents ,Multidisciplinary ,Organic Compounds ,Chemical Reactions ,Neurochemistry ,Nucleosides ,Visual identification ,Neurotransmitters ,021001 nanoscience & nanotechnology ,Serotonin metabolism ,Glycosylamines ,Chemistry ,Bioassays and Physiological Analysis ,Physical Sciences ,Medicine ,0210 nano-technology ,Biological system ,Oxidation-Reduction ,Research Article ,Analyte ,Biogenic Amines ,Serotonin ,Epinephrine ,Science ,Fast-scan cyclic voltammetry ,Surgical and Invasive Medical Procedures ,010402 general chemistry ,Research and Analysis Methods ,Oxidation ,Animals ,Humans ,Dopamine metabolism ,Bioelectrochemical Analysis ,Functional Electrical Stimulation ,Extramural ,Organic Chemistry ,Chemical Compounds ,Biology and Life Sciences ,Oxidation reduction ,Electrochemical Techniques ,Hormones ,0104 chemical sciences ,Rats ,Sources of error ,Biochemical Analysis ,Microelectrodes ,Neuroscience - Abstract
Modern techniques for estimating basal levels of electroactive neurotransmitters rely on the measurement of oxidative charges. This requires time integration of oxidation currents at certain intervals. Unfortunately, the selection of integration intervals relies on ad-hoc visual identification of peaks on the oxidation currents, which introduces sources of error and precludes the development of automated procedures necessary for analysis and quantification of neurotransmitter levels in large data sets. In an effort to improve charge quantification techniques, here we present novel methods for automatic selection of integration boundaries. Our results show that these methods allow quantification of oxidation reactions both in vitro and in vivo and of multiple analytes in vitro.
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- 2021
9. A Low-Cost Humidity Control System to Protect Microscopes in a Tropical Climate
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J. Luis Lujan, Anders J. Asp, Christina M. Webber, Evan N. Nicolai, Ephraim I. Ben-Abraham, John W. Wilson, Gabriel Martínez-Gálvez, and Victoria S. Marks
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Fungal growth ,Infectious and parasitic diseases ,RC109-216 ,Improper storage ,Hygroscopic Agents ,Toxicology ,03 medical and health sciences ,0302 clinical medicine ,Tropical climate ,Diagnostic equipment ,Humans ,Relative humidity ,030212 general & internal medicine ,High humidity ,Original Research ,Microscopy ,Tropical Climate ,030503 health policy & services ,Fungi ,Humidity ,food and beverages ,General Medicine ,Silicon Dioxide ,Belize ,6. Clean water ,humanities ,Equipment and Supplies ,13. Climate action ,Costs and Cost Analysis ,Equipment Contamination ,Environmental science ,Public aspects of medicine ,RA1-1270 ,0305 other medical science - Abstract
Introduction: A clean and functional microscope is necessary for accurate diagnosis of infectious diseases. In tropical climates, high humidity levels and improper storage conditions allow for the accumulation of debris and fungus on the optical components of diagnostic equipment, such as microscopes. Objective: Our objective was to develop and implement a low-cost, sustainable, easy to manage, low-maintenance, passive humidity control chamber to both reduce debris accumulation and microbial growth onto the optical components of microscopes. Methods: Constructed from easily-sourced and locally available materials, the cost of each humidity control chamber is approximately $2.35 USD. Relative humidity levels were recorded every 30 minutes over a period of 10 weeks from two chambers deployed at the Belize Vector and Ecology Center and the University of Belize. Results: The humidity control chamber deployed at the University of Belize maintained internal relative humidity at an average of 35.3% (SD = 4.2%) over 10 weeks, while the average external relative humidity was 86.4% (SD = 12.4%). The humidity control chamber deployed at the Belize Vector and Ecology Center effectively maintained internal relative humidity to an average of 54.5% (SD = 9.4%) over 10 weeks, while the average external relative humidity was 86.9% (SD = 12.9%). Conclusions: Control of relative humidity is paramount for the sustainability of medical equipment in tropical climates. The humidity control chambers reduced relative humidity to levels that were not conducive for fungal growth while reducing microscope contamination from external sources. This will likely extend the service life of the microscopes while taking advantage of low-cost, locally sourced components.
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- 2020
10. Developing Strategies for Sustainable Medical Equipment Maintenance in Under-Resourced Settings
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Sara Aristizabal, Anders J. Asp, Gabriel Martínez-Gálvez, Christina M. Webber, J. Luis Lujan, Maria A. Gonzalez Porras, Manuela Lopera Higuita, John W. Wilson, Ephraim I. Ben-Abraham, and Brent M. Berry
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Process management ,Maintenance ,Organizations, Nonprofit ,Developing country ,Medical equipment ,Infectious and parasitic diseases ,RC109-216 ,Original research ,03 medical and health sciences ,0302 clinical medicine ,Stakeholder Participation ,Health care ,Humans ,030212 general & internal medicine ,Developing Countries ,Sustainable solutions ,business.industry ,Teaching ,030503 health policy & services ,General Medicine ,Preventive maintenance ,Editorial ,Equipment and Supplies ,Sustainability ,Health Resources ,Public aspects of medicine ,RA1-1270 ,0305 other medical science ,business ,Equipment and Supplies Utilization ,Limited resources ,Needs Assessment ,Program Evaluation - Abstract
Engineering technology plays a pivotal role in the delivery of health care in under-resourced countries by providing an infrastructure to improve patient outcomes. However, sustainability of these technologies is difficult in these settings oftentimes due to limited resources or training. The framework presented in this editorial focuses on establishing medical and laboratory equipment sustainability in developing countries and is comprised of four steps: 1) establishing reliable in-country relationships with stakeholders, 2) identifying needs for sustainable solutions locally, 3) exploring potential solutions and assessing their effort-to-impact ratios, and 4) working with strategic partners to implement solutions with clear performance metrics. By focusing on the sustainability of donated equipment instead of the equipment itself, this method presented distinguishes itself from other philanthropic endeavors in the field by seeking to establish preventive maintenance habits that can impact clinical outcomes of a community long term. Application of this methodology is reported in the Original Research Article “A Low-Cost Humidity Control System to Protect Microscopes in a Tropical Climate” by Asp et. al.
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- 2020
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11. Medium- and high-intensity rTMS reduces psychomotor agitation with distinct neurobiologic mechanisms
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Anders J. Asp, Kalina Makowiecki, Alesha Heath, Avalon Gray, Daniel R. Lindberg, Jennifer Rodger, Doo Sup Choi, and Paul E. Croarkin
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0301 basic medicine ,Male ,Psychomotor agitation ,medicine.medical_treatment ,Neurogenesis ,Pharmacology ,behavioral disciplines and activities ,Article ,Fluoxetine Hydrochloride ,lcsh:RC321-571 ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Mice ,0302 clinical medicine ,Neurotrophic factors ,mental disorders ,medicine ,Animals ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,Biological Psychiatry ,Psychomotor Agitation ,Depressive Disorder, Major ,business.industry ,Brain-Derived Neurotrophic Factor ,musculoskeletal, neural, and ocular physiology ,Glutamate receptor ,Brain ,Olfactory Bulb ,Transcranial Magnetic Stimulation ,Glutamine ,Transcranial magnetic stimulation ,Mice, Inbred C57BL ,Psychiatry and Mental health ,Disease Models, Animal ,030104 developmental biology ,nervous system ,medicine.symptom ,business ,030217 neurology & neurosurgery ,psychological phenomena and processes ,Behavioural despair test - Abstract
Definitive data are lacking on the mechanism of action and biomarkers of repetitive transcranial magnetic stimulation (rTMS) for the treatment of depression. Low-intensity rTMS (LI-rTMS) has demonstrated utility in preclinical models of rTMS treatments but the effects of LI-rTMS in murine models of depression are unknown. We examined the behavioral and neurobiologic changes in olfactory bulbectomy (OB) mice with medium-intensity rTMS (MI-rTMS) treatment and fluoxetine hydrochloride. We then compared 10-Hz rTMS sessions for 3 min at intensities (measured at the cortical surface) of 4 mT (LI-rTMS), 50 mT (medium-intensity rTMS [MI-rTMS]), or 1 T (high-intensity rTMS [HI-rTMS]) 5 days per week over 4 weeks in an OB model of agitated depression. Behavioral effects were assessed with forced swim test; neurobiologic effects were assessed with brain levels of 5-hydroxytryptamine, brain-derived neurotrophic factor (BDNF), and neurogenesis. Peripheral metabolomic changes induced by OB and rTMS were monitored through enzyme-linked immunosorbent assay and ultrapressure liquid chromatography-driven targeted metabolomics evaluated with ingenuity pathway analysis (IPA). MI-rTMS and HI-rTMS attenuated psychomotor agitation but only MI-rTMS increased BDNF and neurogenesis levels. HI-rTMS normalized the plasma concentration of α-amino-n-butyric acid and 3-methylhistidine. IPA revealed significant changes in glutamine processing and glutamate signaling in the OB model and following MI-rTMS and HI-rTMS treatment. The present findings suggest that MI-rTMS and HI-rTMS induce differential neurobiologic changes in a mouse model of agitated depression. Further, α-amino-n-butyric acid and 3-methylhistidine may have utility as biomarkers to objectively monitor the response to rTMS treatment of depression.
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- 2018
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12. An Injectable Neural Stimulation Electrode Made from an In-Body Curing Polymer/Metal Composite
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Johnathon M. Aho, Evan N. Nicolai, Weifeng Zeng, Bruce E. Knudsen, Aaron J. Suminski, Brian A. Gosink, Anders J. Asp, Kevin D. Malerick, Shyam R. Polaconda, Kip A. Ludwig, Andrea L. McConico, Erika K. Ross, Justin C. Williams, Jannifer H. Lee, Douglas J. Weber, James K. Trevathan, Ian W. Baumgart, Megan L. Settell, Manfred Franke, Sarah K. Brodnick, Zachary Sanger, Andrew J. Shoffstall, and J. Luis Lujan
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Materials science ,Polymers ,Composite number ,Biomedical Engineering ,Pharmaceutical Science ,Biocompatible Materials ,02 engineering and technology ,010402 general chemistry ,Electrochemistry ,01 natural sciences ,Cathodic protection ,Biomaterials ,Peripheral Nerves ,Prepolymer ,Electrodes ,Curing (chemistry) ,Biomaterial ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Dielectric Spectroscopy ,Neural stimulation ,Electrode ,0210 nano-technology ,Porosity ,Biomedical engineering - Abstract
Implanted neural stimulation and recording devices hold vast potential to treat a variety of neurological conditions, but the invasiveness, complexity, and cost of the implantation procedure greatly reduce access to an otherwise promising therapeutic approach. To address this need, a novel electrode that begins as an uncured, flowable prepolymer that can be injected around a neuroanatomical target to minimize surgical manipulation is developed. Referred to as the Injectrode, the electrode conforms to target structures forming an electrically conductive interface which is orders of magnitude less stiff than conventional neuromodulation electrodes. To validate the Injectrode, detailed electrochemical and microscopy characterization of its material properties is performed and the feasibility of using it to stimulate the nervous system electrically in rats and swine is validated. The silicone-metal-particle composite performs very similarly to pure wire of the same metal (silver) in all measures, including exhibiting a favorable cathodic charge storage capacity (CSCC ) and charge injection limits compared to the clinical LivaNova stimulation electrode and silver wire electrodes. By virtue of its simplicity, the Injectrode has the potential to be less invasive, more robust, and more cost-effective than traditional electrode designs, which could increase the adoption of neuromodulation therapies for existing and new indications.
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- 2019
13. A Truly Injectable Neural Stimulation Electrode Made from an In-Body Curing Polymer/Metal Composite
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Shyam R. Polaconda, Justin C. Williams, Evan N. Nicolai, Bruce E. Knudsen, Johnathon M. Aho, Megan L. Settell, Sarah K. Brodnick, Erika K. Ross, Anders J. Asp, Brian A. Gosink, Kevin D. Malerick, Weifeng Zeng, Aaron J. Suminski, Zachary Sanger, Kip A. Ludwig, Andrea L. McConico, Douglas J. Weber, Jannifer H. Lee, Manfred Franke, Andrew J. Shoffstall, James K. Trevathan, Ian W. Baumgart, and J. Luis Lujan
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Materials science ,medicine.medical_treatment ,Elastomer ,Dielectric spectroscopy ,Cathodic protection ,chemistry.chemical_compound ,Silicone ,chemistry ,Electrode ,medicine ,Cyclic voltammetry ,Vagus nerve stimulation ,Voltage ,Biomedical engineering - Abstract
Implanted neural stimulation and recording devices hold vast potential to treat a variety of neurological conditions, but the invasiveness, complexity, and cost of the implantation procedure greatly reduce access to an otherwise promising therapeutic approach. To address this need, we have developed a novel electrode that begins as an uncured, flowable pre-polymer that can be injected around a neuroanatomical target to minimize surgical manipulation. Referred to as the Injectrode, the electrode conforms to complex target structures such as a foramen or plexus, and within minutes cures in vivo forming an electrically conductive interface. The resulting interface has a Young’s Modulus of under 100 kPa, which is orders of magnitude less stiff than conventional neuromodulation electrodes. To validate the Injectrode, we performed detailed electrochemical and microscopy characterization of its material properties and validated the feasibility of using it to electrically stimulate the nervous system in pre-clinical animal models. Electrochemical testing was performed based on common FDA preclinical benchtop tests including scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, and voltage transient analysis. The metal particle based Injectrode within the cured silicone elastomer performed very similarly to pure wire of the same metal (silver) in all measures. Additionally, the Injectrode demonstrated favorable cathodic charge storage capacity (CSCC) and charge injection limits compared to size-matched mimics of the clinical LivaNova stimulation electrodes and silver wire electrodes, putatively resulting from the increase in fractal dimension/accessible surface area within the silicone matrix for electrochemical reactions. Acute in vivo testing of an Injectrode placed around the complex compound motor nerve branches of the brachial plexus proved that low current stimulation-induced tetanic activation of the terminal muscles was feasible. Finally, to establish proof of concept in an animal model better matching the scale of human anatomy, direct comparisons of the Injectrode performance to the clinical LivaNova lead were made by evoking heart rate changes via vagus nerve stimulation in swine. By virtue of being simpler than traditional electrode designs, less invasive, and more cost-effective, the Injectrode has the potential to increase the adoption of neuromodulation therapies for existing and new indications.
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- 2019
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14. Cell-Free DNA after Heart Transplantation: New Aspects of the Story
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Anne Ricksten, Kristjan Karason, Göran Dellgren, J. Asp, D. Andersson, J. Boehmer, J. Sunnegardh, A. Stahlberg, Håkan Wåhlander, and Carina Wasslavik
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Pulmonary and Respiratory Medicine ,Heart transplantation ,Transplantation ,Cell-free fetal DNA ,business.industry ,medicine.medical_treatment ,Cancer research ,medicine ,Surgery ,Cardiology and Cardiovascular Medicine ,business - Published
- 2021
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15. A Standardized Protocol for Donor-Derived Cell-Free DNA Quantification in the Diagnosis of Allograft Injury
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Håkan Wåhlander, D. Andersson, J. Asp, Anne Ricksten, A. Stahlberg, J. Boehmer, Göran Dellgren, J. Sunnegardh, Kristjan Karason, and Carina Wasslavik
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Pulmonary and Respiratory Medicine ,Heart transplantation ,Transplantation ,medicine.medical_specialty ,Clinical events ,business.industry ,medicine.medical_treatment ,Urology ,medicine.disease ,Cell-free fetal DNA ,Heart failure ,Genotype ,medicine ,Surgery ,Donor derived ,Cardiology and Cardiovascular Medicine ,Prospective cohort study ,business - Abstract
Purpose There is an increasing interest in the use of donor-derived cfDNA (dd-cfDNA) in transplantation for non-invasive diagnosis of allograft injury. We hereby describe a non-commercial routine procedure for dd-cfDNA detection and quantification using digital droplet PCR and target-specific preamplification of a SNP-panel of 35 SNP-assays. The method is based on the difference in genotype between recipients and donors. After establishing our protocol, it has been used in a prospective study following recipients for 12 months after heart transplantation (HTx), and we here briefly describe our protocol. Methods A total of 728 samples from 67 HTx patients have been retrieved and analyzed. The recipients were genotyped preoperatively with respect to the SNP-panel. Upon transplantation, the donor genotype was interrogated with respect to the homozygous alleles found in the recipient. After HTx, blood samples were collected in cell free DNA collection tubes and delivered within the same day to the hospital laboratory. Plasma was separated by centrifugation at 2000g and 16000g, respectively. Isolated plasma was stored at -80C or used immediately for cfDNA extraction. Quality controls were performed by the 4200 Tape Station. The same primers were used for preamplification and downstream PCR. Non-template controls were included in all preamplification steps. The amount of dd-cfDNA was calculated as a fraction of the total cfDNA. Results The variation of extracted cfDNA yield was 10-130 ng/ml plasma. The 50-800 bp sized cfDNA constitutes 90% of the extracted samples, indicating a low background. An average of 2-5 informative SNPS assays for each transplant recipient were used for dd-cfDNA quantification with a detection rate down to 0.01% dd-cfDNA. Elevation of dd-cfDNA was seen not only in conjunction with cellular rejection but also during infection and in episodes of heart failure Conclusion Samples from HTx recipients demonstrated low levels of dd-cfDNA in consecutive samples during optimal treatment in non-eventful cases. Elevation of dd-cfDNA was seen not only during rejection but also in other conditions. This non-invasive method is relatively cheap, enables large sample yields by preamplification, has a fast turn-around time (48 hours) and is thus useful for clinical monitoring of HTx patients. However, it needs to be carefully related to clinical events.
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- 2021
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16. Calcium imaging in freely moving mice during electrical stimulation of deep brain structures
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James K. Trevathan, Takashi D. Y. Kozai, Evan N. Nicolai, Stephani Otte, Mike J. Schachter, Jonathan J. Nassi, David Cheng, Anders J. Asp, Jones Griffith Parker, Nicholas A Kremer, Kip A. Ludwig, J. Luis Lujan, and Jonathan M Trevathan
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Deep brain stimulation ,Parkinson's disease ,business.industry ,medicine.medical_treatment ,0206 medical engineering ,Biomedical Engineering ,Stimulation ,02 engineering and technology ,medicine.disease ,020601 biomedical engineering ,Neuromodulation (medicine) ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Subthalamic nucleus ,0302 clinical medicine ,medicine.anatomical_structure ,Calcium imaging ,GCaMP ,medicine ,Neuropil ,business ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Objective. After decades of study in humans and animal models, there remains a lack of consensus regarding how the action of electrical stimulation on neuronal and non-neuronal elements—e.g. neuropil, cell bodies, glial cells, etc.—leads to the therapeutic effects of neuromodulation therapies. To further our understanding of neuromodulation therapies, there is a critical need for novel methodological approaches using state-of-the-art neuroscience tools to study neuromodulation therapy in preclinical models of disease. Approach. In this manuscript we outline one such approach combining chronic behaving single-photon microendoscope recordings in a pathological mouse model with electrical stimulation of a common deep brain stimulation (DBS) target. We describe in detail the steps necessary to realize this approach, as well as discuss key considerations for extending this experimental paradigm to other DBS targets for different therapeutic indications. Additionally, we make recommendations from our experience on implementing and validating the required combination of procedures that includes: the induction of a pathological model (6-hydroxy dopamine model of Parkinson’s disease) through an injection procedure, the injection of the viral vector to induce GCaMP expression, the implantation of the gradient refractive index lens and stimulation electrode, and the installation of a baseplate for mounting the microendoscope. We proactively identify unique data analysis confounds occurring due to the combination of electrical stimulation and optical recordings and outline an approach to address these confounds. Main results. In order to validate the technical feasibility of this unique combination of experimental methods, we present data to demonstrate that (1) despite the complex multifaceted surgical procedures, chronic optical recordings of hundreds of cells combined with stimulation is achievable over week long periods (2) this approach enables measurement of differences in DBS evoked neural activity between anesthetized and awake conditions and (3) this combination of techniques can be used to measure electrical stimulation induced changes in neural activity during behavior in a pathological mouse model. Significance. These findings are presented to underscore the feasibility and potential utility of minimally constrained optical recordings to elucidate the mechanisms of DBS therapies in animal models of disease.
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- 2021
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17. GEANT4 simulation of cyclotron radioisotope production in a solid target
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P. Takhar, J. Asp, Scott Penfold, Paul Jackson, and F. Poignant
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Diagnostic Imaging ,Nuclear reaction ,Engineering ,Proton ,Nuclear engineering ,Cyclotron ,Monte Carlo method ,Biophysics ,General Physics and Astronomy ,01 natural sciences ,law.invention ,User-Computer Interface ,Nickel ,law ,0103 physical sciences ,Computer Graphics ,Humans ,Computer Simulation ,Radiology, Nuclear Medicine and imaging ,010306 general physics ,Copper Radioisotopes ,Simulation ,Radioisotopes ,Range (particle radiation) ,010308 nuclear & particles physics ,business.industry ,General Medicine ,Cyclotrons ,Yield (chemistry) ,Radiopharmaceuticals ,business ,Monte Carlo Method ,Algorithms ,Copper ,Software ,Beam (structure) - Abstract
The use of radioisotopes in nuclear medicine is essential for diagnosing and treating cancer. The optimization of their production is a key factor in maximizing the production yield and minimizing the associated costs. An efficient approach to this problem is the use of Monte Carlo simulations prior to experimentation. By predicting isotopes yields, one can study the isotope of interest expected activity for different energy ranges. One can also study the target contamination with other radioisotopes, especially undesired radioisotopes of the wanted chemical element which are difficult to separate from the irradiated target and might result in increasing the dose when delivering the radiopharmaceutical product to the patient. The aim of this work is to build and validate a Monte Carlo simulation platform using the GEANT4 toolkit to model the solid target system of the South Australian Health and Medical Research Institute (SAHMRI) GE Healthcare PETtrace cyclotron. It includes a GEANT4 Graphical User Interface (GUI) where the user can modify simulation parameters such as the energy, shape and current of the proton beam, the target geometry and material, the foil geometry and material and the time of irradiation. The paper describes the simulation and presents a comparison of simulated and experimental/theoretical yields for various nuclear reactions on an enriched nickel 64 target using the GEANT4 physics model QGSP_BIC_AllHP, a model recently developed to evaluate with high precision the interaction of protons with energies below 200MeV available in Geant4 version 10.1. The simulation yield of the (64)Ni(p,n)(64)Cu reaction was found to be 7.67±0.074 mCi·μA(-1) for a target energy range of 9-12MeV. Szelecsenyi et al. (1993) gives a theoretical yield of 6.71mCi·μA(-1) and an experimental yield of 6.38mCi·μA(-1). The (64)Ni(p,n)(64)Cu cross section obtained with the simulation was also verified against the yield predicted from the nuclear database TENDL and compared to experimental yield obtained from literature.
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- 2016
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18. Reversal of morphine-induced cell-type–specific synaptic plasticity in the nucleus accumbens shell blocks reinstatement
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Stephanie R. Ebner, Matthew C. Hearing, Anna E. Ingebretson, Anders J. Asp, Mark J. Thomas, Rachel A. Fischer, Clare E. Schmidt, Jakub Jedynak, and Erin B. Larson
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Male ,0301 basic medicine ,Genotype ,Optical Phenomena ,Long-Term Potentiation ,Mice, Transgenic ,AMPA receptor ,Motor Activity ,Nucleus accumbens ,Medium spiny neuron ,Nucleus Accumbens ,03 medical and health sciences ,0302 clinical medicine ,Dopamine ,Dopamine receptor D2 ,medicine ,Animals ,Receptors, AMPA ,Neurons ,Neuronal Plasticity ,Multidisciplinary ,Morphine ,Ceftriaxone ,Long-term potentiation ,Biological Sciences ,Conditioned place preference ,Anti-Bacterial Agents ,Mice, Inbred C57BL ,Protein Subunits ,030104 developmental biology ,Synaptic plasticity ,Psychology ,Neuroscience ,030217 neurology & neurosurgery ,Signal Transduction ,medicine.drug - Abstract
Drug-evoked plasticity at excitatory synapses on medium spiny neurons (MSNs) of the nucleus accumbens (NAc) drives behavioral adaptations in addiction. MSNs expressing dopamine D1 (D1R-MSN) vs. D2 receptors (D2R-MSN) can exert antagonistic effects in drug-related behaviors, and display distinct alterations in glutamate signaling following repeated exposure to psychostimulants; however, little is known of cell-type-specific plasticity induced by opiates. Here, we find that repeated morphine potentiates excitatory transmission and increases GluA2-lacking AMPA receptor expression in D1R-MSNs, while reducing signaling in D2-MSNs following 10-14 d of forced abstinence. In vivo reversal of this pathophysiology with optogenetic stimulation of infralimbic cortex-accumbens shell (ILC-NAc shell) inputs or treatment with the antibiotic, ceftriaxone, blocked reinstatement of morphine-evoked conditioned place preference. These findings confirm the presence of overlapping and distinct plasticity produced by classes of abused drugs within subpopulations of MSNs that may provide targetable molecular mechanisms for future pharmacotherapies.
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- 2016
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19. Calcium imaging in freely-moving mice during electrical stimulation of deep brain structures
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Anders J. Asp, David Cheng, Takashi D. Y. Kozai, James K. Trevathan, Stephani Otte, Jonathan J. Nassi, Jones Griffith Parker, Nicholas A Kremer, Kip A. Ludwig, Evan N. Nicolai, J. Luis Lujan, Jonathan M Trevathan, and Mike J. Schachter
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Deep brain stimulation ,business.industry ,medicine.medical_treatment ,Stimulation ,Neuromodulation (medicine) ,Subthalamic nucleus ,Electrophysiology ,medicine.anatomical_structure ,Calcium imaging ,GCaMP ,Neuropil ,medicine ,business ,Neuroscience - Abstract
After decades of study in humans and animal models, there remains a lack of consensus regarding how the action of electrical stimulation on neuronal and non-neuronal elements – e.g. neuropil, cell bodies, glial cells, etc. – leads to the therapeutic effects of neuromodulation therapies. To further our understanding of neuromodulation therapies, there is a critical need for novel methodological approaches using state-of-the-art neuroscience tools to study neuromodulation therapy in preclinical models of disease. In this manuscript we outline one such approach combining chronic behaving single-photon microendoscope recordings in a pathological mouse model with electrical stimulation of a common deep brain stimulation (DBS) target. We describe in detail the steps necessary to realize this approach, as well as discuss key considerations for extending this experimental paradigm to other DBS targets for different therapeutic indications. Additionally, we make recommendations from our experience on implementing and validating the required combination of procedures that includes: the induction of a pathological model (6-OHDA model of Parkinson’s disease) through an injection procedure, the injection of the viral vector to induce GCaMP expression, the implantation of the GRIN lens and stimulation electrode, and the installation of a baseplate for mounting the microendoscope. We proactively identify unique data analysis confounds occurring due to the combination of electrical stimulation and optical recordings and outline an approach to address these confounds. In order to validate the technical feasibility of this unique combination of experimental methods, we present data to demonstrate that 1) despite the complex multifaceted surgical procedures, chronic optical recordings of hundreds of cells combined with stimulation is achievable over week long periods 2) this approach enables measurement of differences in DBS evoked neural activity between anesthetized and awake conditions and 3) this combination of techniques can be used to measure electrical stimulation induced changes in neural activity during behavior in a pathological mouse model. These findings are presented to underscore the feasibility and potential utility of minimally constrained optical recordings to elucidate the mechanisms of DBS therapies in animal models of disease.
- Published
- 2018
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20. P2803Rejection diagnostics with digital droplet PCR measuring donor-derived cell-free DNA: A retrospective proof-of-concept study in heart-transplanted patients
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Göran Dellgren, J. Asp, A Ricksten, J Boehmer, and Carina Wasslavik
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Cell-free fetal DNA ,Proof of concept ,business.industry ,Medicine ,Donor derived ,Cardiology and Cardiovascular Medicine ,business ,Molecular biology ,Digital droplet pcr - Published
- 2018
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21. Cell-Free DNA in Different Clinical Scenarios after Heart Transplantation: Shedding Light or Obscuring the Picture?
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Carina Wasslavik, Håkan Wåhlander, Anne Ricksten, Göran Dellgren, Kristjan Karason, J. Boehmer, J. Sunnegardh, J. Asp, and A. Stahlberg
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Pulmonary and Respiratory Medicine ,Heart transplantation ,Transplantation ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,Single-nucleotide polymorphism ,Highly sensitive ,Right heart failure ,Cell-free fetal DNA ,Internal medicine ,Biopsy ,Cardiology ,Medicine ,Surgery ,Primary graft failure ,Cardiology and Cardiovascular Medicine ,business - Abstract
Purpose Donor-derived cell-free DNA (dd-cfDNA) as a highly sensitive marker of rejection after heart transplantation (HTx) has gained emerging interest. Recent studies are based on sequencing techniques and use fractional abundance (dd-cfDNA as a fraction of total cfDNA) as their outcome. Here we present patient examples of the BIODRAFT-study (NCT03477383) based on PCR-techniques. Methods Blood samples are taken prospectively in parallel with endomyocardial biopsies (EMB) during the first year after HTx. dd-cfDNA is analyzed using targeted preamplification of 35 single nucleotide polymorphisms followed by digital droplet-PCR. Outcome is fractional abundance as well as total number of DNA copies, both from the donor and the recipient. Results 71 patients (57 adults, 14 children) are so far included and more than 500 blood samples analyzed. In otherwise stable patients, both fractional abundance and total DNA copies seem to follow biopsy patterns with respect to rejection. However, we could also identify different scenarios in which the distribution of cfDNA seems more complicated than hitherto described: Patients with primary graft failure, clinically silent CMV-infection or mild right heart failure show elevated levels of dd-cfDNA, thus complicating the interpretation of results. Some patients present with markedly elevated levels of their own cfDNA without obvious clinical reasons. Conclusion Besides the well-known concept of fractional abundance, our approach gives results that allow following absolute DNA copy numbers of both donor and recipient. This widens the horizon of cfDNA as a marker of graft injury after HTx, and gives an outlook to clinical scenarios with possible false positive (mimicking rejection) and, even worse, false negative results: high levels of recipient-cfDNA could mask ongoing rejection if only fractional abundance can be reported. The biology of cell-free DNA is complex and seems not yet fully understood.
- Published
- 2019
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22. Synaptic Depotentiation and mGluR5 Activity in the Nucleus Accumbens Drive Cocaine-Primed Reinstatement of Place Preference
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Aric Madayag, Mark J. Thomas, Stephanie R. Ebner, Erin B. Larson, Michael A. Benneyworth, Matthew Hearing, Anders J. Asp, Anna E. Ingebretson, Clare E. Schmidt, and Keelia A. Silvis
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0301 basic medicine ,Male ,Patch-Clamp Techniques ,Infralimbic cortex ,AMPA receptor ,Nucleus accumbens ,Nucleus Accumbens ,03 medical and health sciences ,Mice ,0302 clinical medicine ,Cocaine ,Piperidines ,Receptors, Kainic Acid ,medicine ,Animals ,Receptors, AMPA ,Long-term depression ,Research Articles ,Neuronal Plasticity ,Chemistry ,General Neuroscience ,Long-Term Synaptic Depression ,Synaptic Potentials ,Conditioned place preference ,Electrophysiological Phenomena ,Mice, Inbred C57BL ,Optogenetics ,Thiazoles ,030104 developmental biology ,MTEP ,medicine.anatomical_structure ,Synaptic plasticity ,Conditioning, Operant ,Depotentiation ,Neuroscience ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
Understanding the neurobiological processes that incite drug craving and drive relapse has the potential to help target efforts to treat addiction. The NAc serves as a critical substrate for reward and motivated behavior, in part due to alterations in excitatory synaptic strength within cortical-accumbens pathways. The present studies investigated a causal link between cocaine-induced reinstatement of conditioned place preference and rapid reductions of cocaine-dependent increases in NAc shell synaptic strength in male mice. Cocaine-conditioned place preference behavior and ex vivo whole-cell electrophysiology showed that cocaine-primed reinstatement and synaptic depotentiation were disrupted by inhibiting AMPAR internalization via intra-NAc shell infusion of a Tat-GluA2(3Y) peptide. Furthermore, reinstatement was driven by an mGluR5-dependent reduction in AMPAR signaling. Intra-NAc shell infusion of the mGluR5 antagonist MTEP blocked cocaine-primed reinstatement and corresponding depotentiation, whereas infusion of the mGluR5 agonist CHPG itself promoted reinstatement and depotentiated synaptic strength in the NAc shell. Optogenetic examination of circuit-specific plasticity showed that inhibition of infralimbic cortical input to the NAc shell blocked cocaine-primed reinstatement, whereas low-frequency stimulation (10 Hz) of this pathway in the absence of cocaine triggered a reduction in synaptic strength akin to that observed with cocaine, and was sufficient to promote reinstatement in the absence of a cocaine challenge. These data support a model in which mGluR5-mediated reduction in GluA2-containing AMPARs at NAc shell synapses receiving input from the infralimbic cortex is a critical factor in triggering reinstatement of cocaine-primed conditioned approach behavior. SIGNIFICANCE STATEMENT These studies identified a sequence of neural events whereby reexposure to cocaine activates a signaling cascade that alters synaptic strength in the NAc shell and triggers a behavioral response driven by a drug-associated memory.
- Published
- 2017
23. Multifunctional System for Observing, Measuring and Analyzing Stimulation-Evoked Neurochemical Signaling
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Malcolm B. McIntosh, Kenneth R. Kressin, James K. Trevathan, Diane R. Eaker, Joshua B. Boesche, Christopher J. Kimble, J. Luis Lujan, Anders J. Asp, and Seung Leal Paek
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Computer science ,010401 analytical chemistry ,Stimulation ,01 natural sciences ,Neuromodulation (medicine) ,Article ,0104 chemical sciences ,03 medical and health sciences ,Neural activity ,0302 clinical medicine ,Neurochemical ,Biological neural network ,Electronic engineering ,Neuroscience ,030217 neurology & neurosurgery - Abstract
The ability to measure neurotransmitter activity using implanted electrochemical sensors offers researchers a potent technique for analyzing neural activity across specific neural circuitry. We have developed a wirelessly controlled device, WINCS Harmoni, to observe and measure neurotransmitter dynamics at up to four separate sensors, with high temporal and spatial resolution. WINCS Harmoni also incorporates a versatile neurostimulator that can be synchronized with electrochemical recording. The WINCS Harmoni platform is thus optimally suited for probing the neurochemical effects of neurostimulation, and may in turn enable the development of personalized therapies for multiple brain disorders.
- Published
- 2017
24. Neural Interfaces: An Injectable Neural Stimulation Electrode Made from an In‐Body Curing Polymer/Metal Composite (Adv. Healthcare Mater. 23/2019)
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Weifeng Zeng, Johnathon M. Aho, Aaron J. Suminski, Erika K. Ross, Zachary Sanger, Kevin D. Malerick, Kip A. Ludwig, Andrea L. McConico, Bruce E. Knudsen, Evan N. Nicolai, Shyam R. Polaconda, Jannifer H. Lee, Sarah K. Brodnick, James K. Trevathan, Ian W. Baumgart, Andrew J. Shoffstall, Anders J. Asp, Brian A. Gosink, Douglas J. Weber, Justin C. Williams, Jose L. Lujan, Manfred Franke, and Megan L. Settell
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Biomaterials ,Materials science ,Neural stimulation ,Electrode ,Composite number ,Biomedical Engineering ,Pharmaceutical Science ,Polymer metal ,Curing (chemistry) ,Biomedical engineering - Published
- 2019
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25. Automated production of Cu-64, Zr-89, Ga-68, Ti-45, I-123 and I-124 with a medical cyclotron, using a commercial solid target system
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K. Kuan, William Tieu, C. Lang, M. Malinconico, Prab Takhar, J. Asp, G. Brini, G. Guidi, and F. Boschi
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Cancer Research ,Materials science ,law ,Cyclotron ,Analytical chemistry ,Molecular Medicine ,Radiology, Nuclear Medicine and imaging ,law.invention - Published
- 2019
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26. Design Choices for Next-Generation Neurotechnology Can Impact Motion Artifact in Electrophysiological and Fast-Scan Cyclic Voltammetry Measurements
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Seth A. Hara, Evan N. Nicolai, J. Luis Lujan, James K. Trevathan, Kip A. Ludwig, Kaylene C. Stocking, Nicholas J. Michelson, Megan L. Settell, Takashi D. Y. Kozai, and Anders J. Asp
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Materials science ,Neuroprosthetics ,lcsh:Mechanical engineering and machinery ,Fast-scan cyclic voltammetry ,neuroprosthetics ,02 engineering and technology ,03 medical and health sciences ,0302 clinical medicine ,Neurochemical ,Neurotechnology ,neural interface ,lcsh:TJ1-1570 ,brain-machine interfaces ,Electrical and Electronic Engineering ,Brain–computer interface ,Artifact (error) ,Communication ,Mechanical Engineering ,artifact ,electrode ,electrophysiology ,021001 nanoscience & nanotechnology ,Electrophysiology ,electrochemistry ,Control and Systems Engineering ,fast-scan cyclic voltammetry (FSCV) ,neuromodulation ,neurotechnology ,Cyclic voltammetry ,0210 nano-technology ,030217 neurology & neurosurgery ,Biomedical engineering - Abstract
Implantable devices to measure neurochemical or electrical activity from the brain are mainstays of neuroscience research and have become increasingly utilized as enabling components of clinical therapies. In order to increase the number of recording channels on these devices while minimizing the immune response, flexible electrodes under 10 µm in diameter have been proposed as ideal next-generation neural interfaces. However, the representation of motion artifact during neurochemical or electrophysiological recordings using ultra-small, flexible electrodes remains unexplored. In this short communication, we characterize motion artifact generated by the movement of 7 µm diameter carbon fiber electrodes during electrophysiological recordings and fast-scan cyclic voltammetry (FSCV) measurements of electroactive neurochemicals. Through in vitro and in vivo experiments, we demonstrate that artifact induced by motion can be problematic to distinguish from the characteristic signals associated with recorded action potentials or neurochemical measurements. These results underscore that new electrode materials and recording paradigms can alter the representation of common sources of artifact in vivo and therefore must be carefully characterized.
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- 2018
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27. Donor-derived Cell-free DNA Investigated by Digital PCR After Targeted Pre-Amplification: A Prospective Clinical Study of Heart-transplant Patients
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J. Asp, D. Andersson, A. Stalberg, Kristjan Karason, Carina Wasslavik, J. Sunnegardh, Anne Ricksten, Göran Dellgren, Håkan Wåhlander, and J. Boehmer
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Pulmonary and Respiratory Medicine ,Oncology ,Transplantation ,medicine.medical_specialty ,business.industry ,Cell-free fetal DNA ,Internal medicine ,medicine ,Prospective clinical study ,Surgery ,Digital polymerase chain reaction ,Transplant patient ,Donor derived ,Cardiology and Cardiovascular Medicine ,business - Published
- 2018
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28. Evaluation of physician eye lens doses during permanent seed implant brachytherapy for prostate cancer
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J M Lawson, Scott Penfold, J. Asp, Loredana G. Marcu, Penfold, SN, Marcu, L, Lawson, JM, and Asp, J
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Male ,medicine.medical_specialty ,lens ,physicians ,medicine.medical_treatment ,brachytherapy ,Brachytherapy ,Radiation Dosage ,Iodine Radioisotopes ,Prostate cancer ,Radiation Monitoring ,Occupational Exposure ,Physicians ,interventional radiology ,Lens, Crystalline ,medicine ,Fluoroscopy ,Humans ,Medical physics ,Waste Management and Disposal ,Radioisotopes ,Dosimeter ,medicine.diagnostic_test ,business.industry ,Phantoms, Imaging ,Public Health, Environmental and Occupational Health ,Prostatic Neoplasms ,General Medicine ,Seed Implantation ,medicine.disease ,fluoroscopy ,Radiological weapon ,Calibration ,Radiology ,Implant ,business ,Monte Carlo Method ,Prostate brachytherapy - Abstract
Treatment of low grade prostate cancer with permanent implant of radioactive seeds has become one of the most common brachytherapy procedures in use today. The implant procedure is usually performed with fluoroscopy image guidance to ensure that the seeds are deployed in the planned locations. In this situation the physician performing the transperineal implant is required to be close to the fluoroscopy unit and dose to the eye lens may be of concern. In 1991 the International Commission on Radiological Protection (ICRP) provided a recommended dose limit of 150mSvyr for occupational exposures to the lens of the eye. With more long term follow-up data, this limit was revised in 2011 to 20mSvyr. With this revised limit in mind, we have investigated the dose to the lens of the eye received by physicians during prostate brachytherapy seed implantation. By making an approximation of annual workload, we have related the dose received to the annual background dose. Through clinical and phantom measurements with thermoluminescent dosimeters, it was found that the excess dose to the physicians eye lens received for a conservative estimate of annual workload was never greater than 100% of the annual background dose. Refereed/Peer-reviewed
- Published
- 2012
29. Microclimatic comparison of lichen heaths and shrubs: shrubification generates atmospheric heating but subsurface cooling during the growing season
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P. Aartsma, J. Asplund, A. Odland, S. Reinhardt, and H. Renssen
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Ecology ,QH540-549.5 ,Life ,QH501-531 ,Geology ,QE1-996.5 - Abstract
Lichen heaths are declining in abundance in alpine and Arctic areas partly due to an increasing competition with shrubs. This shift in vegetation types might have important consequences for the microclimate and climate on a larger scale. The aim of our study is to measure the difference in microclimatic conditions between lichen heaths and shrub vegetation during the growing season. With a paired plot design, we measured the net radiation, soil heat flux, soil temperature and soil moisture on an alpine mountain area in southern Norway during the summer of 2018 and 2019. We determined that the daily net radiation of lichens was on average 3.15 MJ (26 %) lower than for shrubs during the growing season. This was mainly due to a higher albedo of the lichen heaths but also due to a larger longwave radiation loss. Subsequently, we estimate that a shift from a lichen heath to shrub vegetation leads to an average increase in atmospheric heating of 3.35 MJ d−1 during the growing season. Surprisingly, the soil heat flux and soil temperature were higher below lichens than below shrubs during days with high air temperatures. This implies that the relatively high albedo of lichens does not lead to a cooler soil compared to shrubs during the growing season. We predict that the thicker litter layer, the presence of soil shading and a higher evapotranspiration rate at shrub vegetation are far more important factors in explaining the variation in soil temperature between lichens and shrubs. Our study shows that a shift from lichen heaths to shrub vegetation in alpine and Arctic areas will lead to atmospheric heating, but it has a cooling effect on the subsurface during the growing season, especially when air temperatures are relatively high.
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- 2021
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30. Involvement of INK4A gene products in the pathogenesis and development of human osteosarcoma
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M S, Benassi, L, Molendini, G, Gamberi, G, Magagnoli, P, Ragazzini, G A, Gobbi, L, Sangiorgi, L, Pazzaglia, J, Asp, C, Brantsing, and P, Picci
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Adult ,Male ,Osteosarcoma ,Adolescent ,Transcription, Genetic ,Immunoblotting ,Serine Endopeptidases ,Bone Neoplasms ,DNA, Neoplasm ,Exons ,Middle Aged ,Prognosis ,Immunohistochemistry ,Methylation ,Polymerase Chain Reaction ,Fungal Proteins ,Gene Expression Regulation, Neoplastic ,Cell Transformation, Neoplastic ,Biomarkers, Tumor ,Humans ,Female ,Tumor Suppressor Protein p53 ,Child ,Promoter Regions, Genetic ,Cyclin-Dependent Kinase Inhibitor p16 - Abstract
The INK4A tumor suppressor gene plays a crucial role in the regulation of the G1 cell cycle phase. It encodes two transcripts, p16 and p14 alternate reading frame (ARF), involved in retinoblastoma protein (pRb)- and p53- cell growth control pathways, respectively.To define the role of gene status and molecule expression involved in the INK4A regulatory system, immunohistochemistry, immunoblotting, and polymerase chain reaction (PCR) analysis were performed on 35 primary high grade osteosarcomas (OS).Although p16 and p14ARF proteins were found negative or weakly detectable in 60% and 57% of the cases respectively, INK4A gene analysis of exons 1alpha, 1beta and 2 did not reveal any deletion or mutation. However, methylation status of the 5'CpG promoter region, assessed by methylation-specific PCR, was found in 12 out of 21 OSs with negative or weak p16 expression. A statistical analysis based on pRb/p16 and p53/p14ARF staining status showed that pRb and p16 co-expression was inversely correlated to tumor relapse and was a marker for a more favorable prognosis. A statistically significant inverse correlation was found between wt-p53 and p14ARF expression. In the group of wt-p53 tumors, the loss of p14ARF was associated with a decreased expression of p21 protein, suggesting a down-regulation of the transcriptional activity of p53.The current results suggest that, in OS, the altered expression of INK4A products plays a primary role in the deregulation of both pRb and p53 cell growth control pathways, contributing to tumor pathogenesis and development.
- Published
- 2001
31. PB2071: INTRALESIONAL RITUXIMAB IN THE TREATMENT OF PRIMARY CUTANEOUS B-CELL LYMPHOMA
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M. Callejas Charavia, L. Castilla García, J. Aspa, P. García Ramírez, M. Argüello Marina, and C. Martínez Vázquez
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Diseases of the blood and blood-forming organs ,RC633-647.5 - Published
- 2022
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32. The geriatric patient: a creative practice approach
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J A, Greene and J, Asp
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Male ,Patient Care Team ,Geriatric Psychiatry ,Humans ,Dementia ,Female ,Medical History Taking ,Aged - Published
- 1986
33. Specialized management of the Alzheimer's disease patient: does it make a difference? A preliminary progress report
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J A, Greene, J, Asp, and N, Crane
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Alzheimer Disease ,Patients' Rooms ,Humans ,Nursing Homes - Published
- 1985
34. The effects of stand characteristics on reindeer lichens and range use by semi-domesticated reindeer
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T. Helle, J. Aspi, and S.-S. Kilpelä
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ecology ,forestry ,reindeer ,lichen ,pasture ,Animal culture ,SF1-1100 - Abstract
The study was carried out in Kuusamo (66°15'N, 29°05'E) and Inari (68°30'N, 28°15'E), northern Finland, where 24 and 22 Scots pine stands were studied respectively. Clear-cutting (logging residue) caused a decline in lichen biomass for some few years, but otherwise the age of the stand had no effect upon lichen biomass. Instead, a positive correlation was found between litter/logging residue and the mean height of lichens; in Kuusamo, logging residue decreased significantly with the age of the stand. Grazing pressure in terms of fecal group density increased with the age of the stand. The preference of old forests came visible also as a lower mean height of lichens, which eliminates the possibility that the preference of old forests is associated only to the use of arboreal lichens. In Inari, grazing pressure sharply increased after the stand had reached the age of 100 years despite scarce litter/logging residue and fair lichen ranges in younger forests; there prevailed a negative correlation between stand density and grazing pressure. It has been suggested that there might be three main reasons for reindeers preferring old forests: 1) hardening of the snow (because of winds) on clear-cut areas, 2) logging residue preventing digging for the food beneath the snow, and 3) poor visibility in young pine stands (Inari) which might increase predation risk.
- Published
- 1990
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35. The growth rate of Cladonia rangiferina and C. mitis in relation to forest characteristics in northeastern Finland
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Timo Helle, J. Aspi, and L. Tarvainen
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reindeer husbandry ,growth rate ,reindeer lichens ,Animal culture ,SF1-1100 - Abstract
The growth rate of Cladonia rangiferina and C. mitis was studied in Kuusamo, northeastern Finland, where they share more than 90 percent of the total lichen biomass. The material was collected from 5 pine forests of different ages in Calluna-Cladina heaths. The length growth rate of C. rangiferina varied by site from 3.9 to 4.3 mmyr -' and that of C. mitis from 3.0 to 3.5 mmyr-1 C. rangiferina achieved the fastest growth in a younger (60 years) shadowy forest; growth was slowest in a clear-felled area and in an old (180 years), already thinned forest. C. mitis grew fastest in a site with young (10 years old) pine plants and slowest in a younger shadowy site. The results do not support suggestions that clear-felling itself might negatively influence the growth of lichens. However, it is important also from the point of view of range management to create a new forest as soon as possible, since both species studied here grew faster in young forests than in clear-felled areas. Harmaaporonjakalan ja mietoporonjakalan kasvunopeus eri-ikaisissa metsissa. Abstract in Finnish / Yhteenveto: Harmaaporonjakalan (Cladonia rangiferina) ja mietoporonjakalan (Cladonia mitis) kasvunopeutta tutkittiin Kuusamossa. Aineisto kerattiin 5 puustoltaan eri-ikaiselti jakalakankaalta. Harmaaporonjakala kasvoi pituutta keskimaarin 3.9 - 4.3 mm/v ja mietoporonjakala 3.0 - 3.5 mm/v kasvupaikasta riippuen. Harmaaporonjakalan kasvu oli nopeinta nuorehkossa (60 v) tiheassa metsassa, hitainta paljaaksihakkuulla ja vanhassa (180 v), jo harventuneessa metsassa. Mietoporonjakala kasvoi nopeimmin 90 cm:n taimikossa ja hitaimmin varjoisimmalla kasvupaikalla. Tulosten perusteella on vaikea yhtya kasitykseen, etta paljaaksihakkuu sinansa vahentaa poronjakalien kasvunopeutta. Myos poronhoidon kannalta on kuitenkin tarkeaa, etta uusi metsa saadaan aikaan mahdollisimman nopeasti, silla molemmat lajit kasvavat nopeimmin eri-ikaisissa nuorissa metsissa.
- Published
- 1983
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36. Sized-related changes in winter condition of male calves in reindeer
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T. Helle, E. Pulliainen, and J. Aspi
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condition ,fat ,mortality ,normalizing selection ,stabilizing selection ,weight ,Animal culture ,SF1-1100 - Abstract
Size-related changes in body condition of free-ranging male calves of semi-domesticated reindeer were studied in northern Finland from October 1983 to February 1984. In October-November, back fat depth or muscle fat percent correlated positively with the body size (=back length). In January, the highest means especially for muscle fat percent were found among medium-sized calves. Carcass weight and weight/back length ratio correlated positively with size, excluding February sample, where correlation for carcass weight was non-significant and for weight/back length ratio negative. Weight in the autumn correlated negatively with weight in February. Therefore, normalizing selection for body size (working against small and large phenotypes) is expected to occur in late winter. Small calves may be at greater mortality risk because of lower initial body reserves. Large calves commonly disperse during the rutting season and they may suffer most from increased food competition later in winter. Using of medium-sized calves for breeding might be the safest policy on ranges characterized by short food supply and difficult snow conditions. Koon vaikutus poron urosvasojen talviseen kuntoon. Abstract in Finnish / Tiivistelmä: Koon vaikutusta vapaana laiduntavien poron urosvasojen kuntoon tutkittiin Pohjois-Suomessa loka-helmikuussa talvella 1983-84. Loka-marraskuussa selkärasvan paksuus tai lihaksen rasvaprosentti riippui vasan koosta ( = selän pituus). Tammikuussa sen sijaan lihaksen rasvaprosentti oli korkein keskikokoisilla vasoilla. Ruhopaino sekä ruhopaino/selän pituus oli yleensa riippuvainen koosta. Helmikuussa ruhopainon riippuvuus koosta ei ollut enää tilastollisesti merkitsevä, ja koon ja ruhopainon/selänpituuden välinen korrelaatio oli negatiivinen. Eniten painoa menettivät (%) loka-helmikuun välillä suurikokoisimmat vasat. Havainnot viittaavat siihen, että talvella esiintyvä kuolleisuus on normalisoivaa koon suhteen (karsii pieniä ja suuria fenotyyppejä). Pienten vasojen kuolleisuusriski on suuri alunperinkin vähäisen varastoravinnon vuoksi. Suuret vasat puolestaan erkaantuvat usein emistään jo rykimäaikana, ja joutuvat kärsimään eniten talven mittaan kiristyvästä ravintokilpailusta. Niukoilla laitumilla siitokseen on turvallisinta säästää keskikokoisia vasoja. Sammenhengen mellom størrelse og vinterkondisjon hos hankalver av reinsdyr. Abstract in Norwegian / Sammendrag: Størrelses-relaterte forandringer i kroppskondisjon hos fritt beitende han-kalver av semidomestiserte rein er studert i Nord-Finland fra oktober 1983 til februar 1984. I oktober - november korrelerte tykkelsen av ryggfettet eller muskelfett-prosenten positivt med kroppsstørrelsen (= rygglengden). I januar ble de høyeste middelverdier, særlig for muskelfett-prosenten, funnet hos kalver av middels størrelse. Skrott-vekter og vekt/rygglengde-forholdet korrelerte positivt med kroppsstørrelse bortsett fra februar-prøvene, der korrellasjonen for skrott-vekt var ikke-signifikant og for vekt/rygglengde-forholdet var negativt. Vekt om høsten korrelerte negativt med vekt i februar. Derfor ventes et normaliserende utvalg for kroppsvekt (som arbeider mot små og store fenotyper) å skje på senvinteren. Små kalver er utsatt for større dødsrisiko på grunn av lavere kroppsreserver. Store kalver streifer vanligvis under brunsttiden og kan komme til å lide under økt næringskonkurranse på senvinteren. Bruk av middels store kalver i avlen kan være den sikreste metode på beiter som karakteriseres av dårlige næringstilgang og vanskelige snøforhold.
- Published
- 1987
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37. Integral methods for automatic quantification of fast-scan-cyclic-voltammetry detected neurotransmitters.
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Leonardo X Espín, Anders J Asp, James K Trevathan, Kip A Ludwig, and J Luis Lujan
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Medicine ,Science - Abstract
Modern techniques for estimating basal levels of electroactive neurotransmitters rely on the measurement of oxidative charges. This requires time integration of oxidation currents at certain intervals. Unfortunately, the selection of integration intervals relies on ad-hoc visual identification of peaks on the oxidation currents, which introduces sources of error and precludes the development of automated procedures necessary for analysis and quantification of neurotransmitter levels in large data sets. In an effort to improve charge quantification techniques, here we present novel methods for automatic selection of integration boundaries. Our results show that these methods allow quantification of oxidation reactions both in vitro and in vivo and of multiple analytes in vitro.
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- 2021
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38. A Low-Cost Humidity Control System to Protect Microscopes in a Tropical Climate
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Anders J. Asp, Christina M. Webber, Evan N. Nicolai, Gabriel Martínez-Gálvez, Victoria S. Marks, Ephraim I. Ben-Abraham, John W. Willson, and J. Luis Luján
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Infectious and parasitic diseases ,RC109-216 ,Public aspects of medicine ,RA1-1270 - Abstract
Introduction: A clean and functional microscope is necessary for accurate diagnosis of infectious diseases. In tropical climates, high humidity levels and improper storage conditions allow for the accumulation of debris and fungus on the optical components of diagnostic equipment, such as microscopes. Objective: Our objective was to develop and implement a low-cost, sustainable, easy to manage, low-maintenance, passive humidity control chamber to both reduce debris accumulation and microbial growth onto the optical components of microscopes. Methods: Constructed from easily-sourced and locally available materials, the cost of each humidity control chamber is approximately $2.35 USD. Relative humidity levels were recorded every 30 minutes over a period of 10 weeks from two chambers deployed at the Belize Vector and Ecology Center and the University of Belize. Results: The humidity control chamber deployed at the University of Belize maintained internal relative humidity at an average of 35.3% (SD = 4.2%) over 10 weeks, while the average external relative humidity was 86.4% (SD = 12.4%). The humidity control chamber deployed at the Belize Vector and Ecology Center effectively maintained internal relative humidity to an average of 54.5% (SD = 9.4%) over 10 weeks, while the average external relative humidity was 86.9% (SD = 12.9%). Conclusions: Control of relative humidity is paramount for the sustainability of medical equipment in tropical climates. The humidity control chambers reduced relative humidity to levels that were not conducive for fungal growth while reducing microscope contamination from external sources. This will likely extend the service life of the microscopes while taking advantage of low-cost, locally sourced components.
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- 2020
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39. Design Choices for Next-Generation Neurotechnology Can Impact Motion Artifact in Electrophysiological and Fast-Scan Cyclic Voltammetry Measurements
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Evan N. Nicolai, Nicholas J. Michelson, Megan L. Settell, Seth A. Hara, James K. Trevathan, Anders J. Asp, Kaylene C. Stocking, J. Luis Lujan, Takashi D.Y. Kozai, and Kip A. Ludwig
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electrode ,artifact ,electrophysiology ,electrochemistry ,fast-scan cyclic voltammetry (FSCV) ,neurotechnology ,neural interface ,neuromodulation ,neuroprosthetics ,brain-machine interfaces ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
Implantable devices to measure neurochemical or electrical activity from the brain are mainstays of neuroscience research and have become increasingly utilized as enabling components of clinical therapies. In order to increase the number of recording channels on these devices while minimizing the immune response, flexible electrodes under 10 µm in diameter have been proposed as ideal next-generation neural interfaces. However, the representation of motion artifact during neurochemical or electrophysiological recordings using ultra-small, flexible electrodes remains unexplored. In this short communication, we characterize motion artifact generated by the movement of 7 µm diameter carbon fiber electrodes during electrophysiological recordings and fast-scan cyclic voltammetry (FSCV) measurements of electroactive neurochemicals. Through in vitro and in vivo experiments, we demonstrate that artifact induced by motion can be problematic to distinguish from the characteristic signals associated with recorded action potentials or neurochemical measurements. These results underscore that new electrode materials and recording paradigms can alter the representation of common sources of artifact in vivo and therefore must be carefully characterized.
- Published
- 2018
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40. Clinical Examples of the Additive Value of Absolute Quantification of Cell-Free DNA After Heart Transplantation.
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Böhmer J, Wåhlander H, Karason K, Sunnegårdh J, Wasslavik C, Jonsson M, Asp J, Ricksten A, and Dellgren G
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- Humans, Male, Female, Adult, Middle Aged, Follow-Up Studies, Prognosis, Child, Tissue Donors, Postoperative Complications diagnosis, Postoperative Complications blood, Young Adult, Graft Survival, Adolescent, Aged, Heart Transplantation adverse effects, Cell-Free Nucleic Acids blood, Graft Rejection diagnosis, Graft Rejection etiology, Graft Rejection blood, Biomarkers blood
- Abstract
Objective: Cell-free DNA (cfDNA) is used as a biomarker after transplantation to detect graft injury, relying on the donor fraction (DF). We have established a PCR-based approach allowing us to separately quantify absolute values of dd-cfDNA and recipient-derived cfDNA (rd-cfDNA). We aimed to present typical clinical scenarios after heart transplantation (HTx) to illustrate the advantages of absolute cfDNA values over DF., Methods: We used the cfDNA results of our cohort (509 samples of 52 patients followed during the first year after HTx) as background and determined the trajectories of cfDNA in specific clinical situations. We profiled an uncomplicated clinical course, viral and bacterial infections, acute and chronic rejection, and false-negative and false-positive rejections in six patients (five adults, one child)., Results: There was a substantial discrepancy between relative (DF) and absolute cfDNA-levels in several clinical situations. Rd- and dd-cfDNA were independently elevated during episodes of rejection and infection and were better suited to depict treatment response than DF alone., Conclusions: Absolute quantification of cfDNA may offer clinically relevant information additive to DF in various situations after HTx and could be helpful for more accurate monitoring of diagnosis and treatment of rejection., (© 2024 The Author(s). Clinical Transplantation published by Wiley Periodicals LLC.)
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- 2024
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41. Prediction of adverse maternal and perinatal outcomes associated with pre-eclampsia and hypertensive disorders of pregnancy: a systematic review and meta-analysis.
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Bucher V, Mitchell AR, Gudmundsson P, Atkinson J, Wallin N, Asp J, Sennström M, Hildén K, Edvinsson C, Ek J, Hastie R, Cluver C, and Bergman L
- Abstract
Background: Hypertensive disorders of pregnancy are a leading cause of maternal and perinatal morbidity and mortality. If women at high risk for developing complications could be identified early, level of care could be triaged, limited resources could be correctly allocated and targeted interventions to prevent complications could be implemented., Methods: We updated a systematic review and meta-analysis and added single outcomes. Women with hypertensive disorders of pregnancy were included. Exposures were tests predicting adverse maternal and/or perinatal outcomes. We searched Medline, Embase, CINAHL, and Cochrane library from January 2016-February 2024. We included studies identified from the previous review. We calculated effect measures. For similar predictive tests and outcomes, area under the receiver-operating-characteristic curve (AUROC) were pooled. This study was registered by PROSPERO: CRD42022336368., Findings: Of the 2898 studies identified, 80 were included. Thirty were added from the previous review resulting in 110 included studies with 506,178 women. Despite more than 1500 tests being performed, most outcomes could not be pooled due to heterogeneity in populations, tests, and outcome definitions. For maternal outcomes, only studies reporting on the Pre-eclampsia Integrated Estimate of RiSk (fullPIERS) model could be pooled. For the composite outcome within 48-h the AUROC was 0.78 (95% CI 0.71-0.86, N = 8). There was significant heterogeneity ( I
2 = 95.7%). For perinatal outcomes, data were pooled for pulsatility index in the umbilical artery and soluble FMS-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio. Biomarkers like the sFlt-1/PlGF ratio showed promising predictive performance for some outcomes but were not externally validated., Interpretation: Despite including over 100 studies with more than 1500 predictors, we were unable to pool any single maternal outcomes and only a few individual perinatal outcomes. The fullPIERS model was externally validated, showing moderate accuracy which varied across studies and should be validated in each new population. Angiogenic biomarkers showed promise but need validation. Future studies should use standardized outcome measures and validate promising tests., Funding: VB is supported by the Swedish Research Council, Grant number 2020-01481. University of Gothenburg., Competing Interests: We declare no competing interests., (© 2024 The Author(s).)- Published
- 2024
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42. Absolute Quantification of Donor-Derived Cell-Free DNA in Pediatric and Adult Patients After Heart Transplantation: A Prospective Study.
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Böhmer J, Wasslavik C, Andersson D, Ståhlberg A, Jonsson M, Wåhlander H, Karason K, Sunnegårdh J, Nilsson S, Asp J, Dellgren G, and Ricksten A
- Subjects
- Adult, Child, Humans, Biomarkers, Graft Rejection, Prospective Studies, Tissue Donors, Cell-Free Nucleic Acids, Heart Transplantation
- Abstract
In this prospective study we investigated a cohort after heart transplantation with a novel PCR-based approach with focus on treated rejection. Blood samples were collected coincidentally to biopsies, and both absolute levels of dd-cfDNA and donor fraction were reported using digital PCR. 52 patients (11 children and 41 adults) were enrolled (NCT03477383, clinicaltrials.gov), and 557 plasma samples were analyzed. 13 treated rejection episodes >14 days after transplantation were observed in 7 patients. Donor fraction showed a median of 0.08% in the cohort and was significantly elevated during rejection (median 0.19%, p < 0.0001), using a cut-off of 0.1%, the sensitivity/specificity were 92%/56% (AUC ROC-curve: 0.78). Absolute levels of dd-cfDNA showed a median of 8.8 copies/mL and were significantly elevated during rejection (median 23, p = 0.0001). Using a cut-off of 7.5 copies/mL, the sensitivity/specificity were 92%/43% for donor fraction (AUC ROC-curve: 0.75). The results support the feasibility of this approach in analyzing dd-cfDNA after heart transplantation. The obtained values are well aligned with results from other trials. The possibility to quantify absolute levels adds important value to the differentiation between ongoing graft damage and quiescent situations., 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 © 2023 Böhmer, Wasslavik, Andersson, Ståhlberg, Jonsson, Wåhlander, Karason, Sunnegårdh, Nilsson, Asp, Dellgren and Ricksten.)
- Published
- 2023
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43. The clinical relevance of broad mutational screening of myeloproliferative neoplasms at diagnosis.
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Pettersson H, Adamsson J, Johansson P, Nilsson S, Palmqvist L, Andréasson B, and Asp J
- Abstract
Introduction: Myeloproliferative neoplasm (MPN) is a heterogenous group of hematological malignancies including polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). JAK2 V617F is the most frequent driver mutation in all three entities, but in PMF and ET mutations in CALR and MPL are also frequent. Mutations seen in additional genes are also often the same regardless of subtype of MPN. The aim of this study was to analyze a population based MPN cohort for genetic variants with prognostic value that can guide clinical decisions., Methods: MPN patients from Western Sweden diagnosed between 2008-2013 (n=248) were screened for mutations in 54 genes associated with myeloid malignancy., Results: Mutations in the genes SRSF2 and U2AF1 correlated significantly with impaired overall survival but did not correlate to increased risk for vascular events, neither before nor after diagnosis. Rather, mutations in these genes showed an association with disease transformation. Several recurrent gene variants with allele frequency close to 50% were confirmed to be germline. However, none of these variants was found to have an earlier onset of MPN., Discussion: In conclusion, we identified gene mutations to be independent markers of impaired survival in MPN. This indicates the need for more individualized assessment and treatment of MPN patients and a wider gene mutation screening already at diagnosis. This could ensure the identification of patients with high-risk mutations early on. In addition, several genetic variants were also identified as germline in this study but gave no obvious clinical relevance. To avoid conclusions from non-informative genetic variants, a simultaneous analysis of normal cell DNA from patients at diagnosis should be considered., 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 © 2023 Pettersson, Adamsson, Johansson, Nilsson, Palmqvist, Andréasson and Asp.)
- Published
- 2023
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44. Alcohol exposure prior to pregnancy-does hazardous consumption affect placenta- and inflammatory-mediated pregnancy outcomes? A Swedish population-based cohort study.
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Asp J, Bergman L, Lager S, Axelsson O, Wikström AK, and Hesselman S
- Subjects
- Pregnancy, Female, Infant, Newborn, Humans, Pregnancy Outcome epidemiology, Cohort Studies, Sweden epidemiology, Ethanol adverse effects, Placenta, Premature Birth epidemiology, Premature Birth etiology, Alcoholism complications
- Abstract
Introduction: Alcohol consumption during pregnancy is related to severe birth complications such as low birthweight, preterm birth and birth defects. During the last decade, the Alcohol Use Disorders Identification Test (AUDIT) has been used as a screening tool in Swedish maternal healthcare units to identify hazardous, pre-pregnancy alcohol use. However, evaluation of the screening with AUDIT, as well as adverse maternal or neonatal outcomes, has not been assessed at a national level., Material and Methods: This was a population-based cohort study of 530 458 births from 2013 to 2018 using demographic, reproductive and maternal health data from the Swedish Pregnancy Register. Self-reported alcohol consumption in the year before pregnancy, measured as AUDIT scores, was categorized into moderate (6-13 points) and high-risk (14-40 points) consumption, with low-risk (0-5 points) consumption as the reference group. Associations with pregnancy- and birth outcomes were explored with logistic regressions using generalized estimating equation models, adjusting for maternal and socioeconomic characteristics. Estimates are presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs)., Results: High-risk and moderate pre-pregnancy alcohol consumption was associated with preeclampsia, preterm birth and birth of an infant small for gestational age (SGA), but these associations were nonsignificant after adjustments. Prior moderate-risk (aOR 1.29, 95% CI 1.17-1.42) and high-risk consumption (aOR 1.62, 95% CI 1.17-2.25) increased the likelihood of intrapartum and neonatal infections., Conclusions: Apart from identifying hazardous alcohol consumption prior to pregnancy and the offer of counseling, screening with the AUDIT in early pregnancy indicates a high risk of inflammatory-/placenta-mediated pregnancy and birth outcomes. For most outcomes, AUDIT was not an independent contributor when adjusting for confounding factors. Hazardous alcohol use prior to pregnancy was independently linked to intrapartum and neonatal infections; conditions associated with morbidity and long-term sequalae. These associations may be explained by alcohol-induced changes in the maternal or fetal immune system in early pregnancy or persistent alcohol intake during pregnancy, or may depend on unidentified confounding factors., (© 2022 The Authors. Acta Obstetricia et Gynecologica Scandinavica published by John Wiley & Sons Ltd on behalf of Nordic Federation of Societies of Obstetrics and Gynecology (NFOG).)
- Published
- 2022
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45. An induced pluripotent stem cell t(7;12)(q36;p13) acute myeloid leukemia model shows high expression of MNX1 and a block in differentiation of the erythroid and megakaryocytic lineages.
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Nilsson T, Waraky A, Östlund A, Li S, Staffas A, Asp J, Fogelstrand L, Abrahamsson J, and Palmqvist L
- Subjects
- Child, Gene Expression genetics, Gene Expression physiology, Gene Expression Profiling, Hematopoietic Stem Cells physiology, Humans, Megakaryocytes physiology, Translocation, Genetic, Cell Differentiation genetics, Homeodomain Proteins genetics, Induced Pluripotent Stem Cells metabolism, Leukemia, Myeloid, Acute genetics, Megakaryocyte-Erythroid Progenitor Cells physiology, Transcription Factors genetics
- Abstract
Acute myeloid leukemia (AML) results from aberrant hematopoietic processes and these changes are frequently initiated by chromosomal translocations. One particular subtype, AML with translocation t(7;12)(q36;p13), is found in children diagnosed before 2 years of age. The mechanisms for leukemogenesis induced by t(7;12) is not understood, in part because of the lack of efficient methods to reconstruct the leukemia-associated genetic aberration with correct genomic architecture and regulatory elements. We therefore created induced pluripotent stem cell (iPSC) lines that carry the translocation t(7;12) using CRISPR/Cas9. These t(7;12) iPSC showed propensity to differentiate into all three germ layers, confirming retained stem cell properties. The potential for differentiation into hematopoietic stem and progenitor cells (HSPC) was shown by expression of CD34, CD43 and CD45. Compared with the parental iPSC line, a significant decrease in cells expressing CD235a and CD41a was seen in the t(7;12) iPSC-derived HSPC (iHSPC), suggesting a block in differentiation. Moreover, colony formation assay showed an accumulation of cells at the erythroid and myeloid progenitor stages. Gene expression analysis revealed significant down-regulation of genes associated with megakaryocyte differentiation and up-regulation of genes associated with myeloid pathways but also genes typically seen in AML cases with t(7;12). Thus, this iPSC t(7;12) leukemia model of the t(7;12) AML subtype constitutes a valuable tool for further studies of the mechanisms for leukemia development and to find new treatment options., (© 2022 The Authors. International Journal of Cancer published by John Wiley & Sons Ltd on behalf of UICC.)
- Published
- 2022
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46. Short-time least squares spectral analysis of pass-by noise in water from a rigid inflatable boat.
- Author
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Lindberg A, Lövgren B, Asp J, Antoni J, and Gällström A
- Abstract
This paper investigates least squares spectral analysis as a tool to analyze non-stationary signals from pass-by noise measurements in water. The spectral analysis involves successive least squares fitting of a finite Fourier series to approximate the observation in a piecewise manner. The least squares spectral analysis is used to search the signals for first- and second-order periodicity as well as the presence of fundamental periodicity. A first-order analysis reveals line components in the signals, whereas a second-order analysis reveals periodic amplitude modulations. Analysis with a higher-order finite Fourier series reveals harmonic structures in the signals. The main contribution of this paper is the model of a magnitude-squared cosine wave which can be used to analyze second-order periodicity. The developed short-time least squares spectral analysis is illustrated on noise radiated from a rigid inflatable boat in shallow water.
- Published
- 2022
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47. Comparison of RNA- and DNA-based methods for measurable residual disease analysis in NPM1-mutated acute myeloid leukemia.
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Pettersson L, Johansson Alm S, Almstedt A, Chen Y, Orrsjö G, Shah-Barkhordar G, Zhou L, Kotarsky H, Vidovic K, Asp J, Lazarevic V, Saal LH, Fogelstrand L, and Ehinger M
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- Adult, Aged, DNA, Neoplasm genetics, Female, Humans, Leukemia, Myeloid, Acute genetics, Male, Middle Aged, Neoplasm, Residual blood, Nuclear Proteins genetics, Nucleophosmin, RNA, Neoplasm genetics, DNA, Neoplasm blood, Leukemia, Myeloid, Acute blood, Mutation, Nuclear Proteins metabolism, RNA, Neoplasm blood, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction
- Abstract
Introduction: Reverse transcriptase quantitative PCR (RT-qPCR) is considered the method of choice for measurable residual disease (MRD) assessment in NPM1-mutated acute myeloid leukemia (AML). MRD can also be determined with DNA-based methods offering certain advantages. We here compared the DNA-based methods quantitative PCR (qPCR), droplet digital PCR (ddPCR), and targeted deep sequencing (deep seq) with RT-qPCR., Methods: Of 110 follow-up samples from 30 patients with NPM1-mutated AML were analyzed by qPCR, ddPCR, deep seq, and RT-qPCR. To select DNA MRD cutoffs for bone marrow, we performed receiver operating characteristic analyses for each DNA method using prognostically relevant RT-qPCR cutoffs., Results: The DNA-based methods showed strong intermethod correlation, but were less sensitive than RT-qPCR. A bone marrow cutoff at 0.1% leukemic DNA for qPCR or 0.05% variant allele frequency for ddPCR and deep seq offered optimal sensitivity and specificity with respect to 3 log
10 reduction of NPM1 transcripts and/or 2% mutant NPM1/ABL. With these cutoffs, MRD results agreed in 95% (191/201) of the analyses. Although more sensitive, RT-qPCR failed to detect leukemic signals in 10% of samples with detectable leukemic DNA., Conclusion: DNA-based MRD techniques may complement RT-qPCR for assessment of residual leukemia. DNA-based methods offer high positive and negative predictive values with respect to residual leukemic NPM1 transcripts at levels of importance for response to treatment. However, moving to DNA-based MRD methods will miss a proportion of patients with residual leukemic RNA, but on the other hand some MRD samples with detectable leukemic DNA can be devoid of measurable leukemic RNA., (© 2021 The Authors. International Journal of Laboratory Hematology published by John Wiley & Sons Ltd.)- Published
- 2021
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48. ASXL1 mutations, previous vascular complications and age at diagnosis predict survival in 85 WHO-defined polycythaemia vera patients.
- Author
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Andréasson B, Pettersson H, Wasslavik C, Johansson P, Palmqvist L, and Asp J
- Subjects
- Adult, Age Factors, Aged, Aged, 80 and over, Comorbidity, DNA (Cytosine-5-)-Methyltransferases genetics, DNA Methyltransferase 3A, DNA Mutational Analysis, DNA-Binding Proteins genetics, Dioxygenases, Disease Progression, Female, Humans, Janus Kinase 2 genetics, Kaplan-Meier Estimate, Male, Middle Aged, Multivariate Analysis, Mutation, Polycythemia Vera complications, Polycythemia Vera genetics, Proto-Oncogene Proteins genetics, Thromboembolism epidemiology, Polycythemia Vera mortality, Repressor Proteins genetics
- Abstract
Polycythaemia vera (PV) patients have an overall comparatively favourable prognosis, but disease progression is very heterogeneous and life-threatening thrombosis and bleedings are frequent complications in untreated disease. Moreover, transformation to more severe secondary myelofibrosis and acute myeloid leukaemia can occur. The aim of this study was to identify gene mutations that could be used together with clinical data as prognostic markers to guide treatment decisions in PV patients. A well-characterized WHO-defined cohort of PV patients was used. Clinical data and blood values were evaluated and a myeloid sequencing panel was used to screen for additional mutations other than the diagnostic JAK2 V617F and JAK2 exon 12 mutations. In 78% of the PV patients, at least one mutation additional to JAK2 V617F was detected. Additional mutations in genes coding for epigenetic modifiers, like TET2, DNMT3A and ASXL1, were most frequent. When correlated to overall survival, mutations in ASXL1 were significantly associated with inferior survival. In an attempt to obtain prognostic guidance in a larger number of patients, the presence of ASXL1 mutations was combined with age and vascular complications prior to diagnosis. Based on these data we were able to define three risk groups that predicted survival., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)
- Published
- 2020
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49. Design and verification of an external radiobiological beam port on a 16.5 MeV GE PETtrace proton cyclotron.
- Author
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Asp J, Santos AMC, Moghaddasi L, Afshar SV, and Bezak E
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- Computer Simulation, Cyclotrons, Dose-Response Relationship, Radiation, Electricity, Equipment Design, Humans, Monte Carlo Method, Protons, Radiobiology, Reproducibility of Results, Neoplasms radiotherapy, Proton Therapy instrumentation, Proton Therapy methods
- Abstract
Purpose: Protons and heavy ions are considered to be ideal particles for use in external beam radiotherapy due to the superior properties of the dose distribution. While a photon (x-ray) beam delivers considerable dose to healthy tissues around the tumor, a proton beam that is delivered with sufficient energies has: a low entrance dose (the dose in front of the tumor); a high-dose region within the tumor, known as the Bragg peak; and, no exit dose beyond the tumor. Proton therapy is the next major step in advancing radiotherapy treatment. The purpose of this project was to adapt an existing radioisotope production cyclotron, a General Electric (GE) PETtrace, to enable radiobiological studies using proton beams. During routine use the PETtrace delivers 16.5 MeV protons to target with beam currents in the range of 10-100 µA resulting in dose rates in the order of kGy/s. To achieve the aim of the project the dose rate had to be reduced to the Gy/min range, without attenuating the proton energy below 5 MeV. This paper covers the design, construction and validation of the beam port., Methods: Monte Carlo simulations were performed, using GEANT4, SRIM and PACE4 to design the beam port and optimize its components. Once the beam port was fabricated, validation experiments were performed using EBT3 and HD-V2 Gafchromic™ films, and a Keithley 6485 picoampere meter., Results and Conclusion: The external beam port was successfully modeled, designed and fabricated. By using a 0.25 mm thick gold foil and a brass pin-hole collimator the beam was spread from a narrow full beam diameter of 10 mm to a wide beam with a 5% flatness area in the center of the beam that had a diameter of ~20 mm. In using this system the dose rate was reduced from kGy/s to ~30 Gy/min., (© 2019 American Association of Physicists in Medicine.)
- Published
- 2020
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50. Transcriptional sex and regional differences in paired human atrial and ventricular cardiac biopsies collected in vivo.
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Synnergren J, Vukusic K, Dönnes P, Jonsson M, Lindahl A, Dellgren G, Jeppsson A, and Asp J
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- Aged, Aged, 80 and over, Aortic Valve surgery, Biopsy, Cluster Analysis, Coronary Artery Bypass, Female, Gene Expression Regulation, Heart Valve Prosthesis Implantation, Humans, Male, Middle Aged, Myocardium metabolism, Oligonucleotide Array Sequence Analysis, Transcriptome, Gene Expression Profiling, Heart Atria metabolism, Heart Ventricles metabolism, Sex Factors, Transcription, Genetic
- Abstract
Transcriptional studies of the human heart provide insight into physiological and pathophysiological mechanisms, essential for understanding the fundamental mechanisms of normal cardiac function and how they are altered by disease. To improve the understanding of why men and women may respond differently to the same therapeutic treatment it is crucial to learn more about sex-specific transcriptional differences. In this study the transcriptome of right atrium and left ventricle was compared across sex and regional location. Paired biopsies from five male and five female patients undergoing aortic valve replacement or coronary artery bypass grafting were included. Gene expression analysis identified 620 differentially expressed transcripts in atrial and ventricular tissue in men and 471 differentially expressed transcripts in women. In total 339 of these transcripts overlapped across sex but notably, 281 were unique in the male tissue and 162 in the female tissue, displaying marked sex differences in the transcriptional machinery. The transcriptional activity was significantly higher in atrias than in ventricles as 70% of the differentially expressed genes were upregulated in the atrial tissue. Furthermore, pathway- and functional annotation analyses performed on the differentially expressed genes showed enrichment for a more heterogeneous composition of biological processes in atrial compared with the ventricular tissue, and a dominance of differentially expressed genes associated with infection disease was observed. The results reported here provide increased insights about transcriptional differences between the cardiac atrium and ventricle but also reveal transcriptional differences in the human heart that can be attributed to sex.
- Published
- 2020
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