scholarly journals Impact of High-Dose Irradiation on Human iPSC-Derived Cardiomyocytes Using Multi-Electrode Arrays: Implications for the Antiarrhythmic Effects of Cardiac Radioablation

2021 ◽  
Vol 23 (1) ◽  
pp. 351
Author(s):  
Jae Sik Kim ◽  
Seong Woo Choi ◽  
Yun-Gwi Park ◽  
Sung Joon Kim ◽  
Chang Heon Choi ◽  
...  
Keyword(s):  
Ventricular Arrhythmias ◽  
Field Potential ◽  
High Dose ◽  
Acute Effects ◽  
Electrode Arrays ◽  
Compensatory Mechanisms ◽  
Active Electrode ◽  
Continuous Increase ◽  
Human Cardiomyocytes ◽  
Dose Irradiation

Cardiac radioablation is emerging as an alternative option for refractory ventricular arrhythmias. However, the immediate acute effect of high-dose irradiation on human cardiomyocytes remains poorly known. We measured the electrical activities of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) upon irradiation with 0, 20, 25, 30, 40, and 50 Gy using a multi-electrode array, and cardiomyocyte function gene levels were evaluated. iPSC-CMs showed to recover their electrophysiological activities (total active electrode, spike amplitude and slope, and corrected field potential duration) within 3–6 h from the acute effects of high-dose irradiation. The beat rate immediately increased until 3 h after irradiation, but it steadily decreased afterward. Conduction velocity slowed in cells irradiated with ≥25 Gy until 6–12 h and recovered within 24 h; notably, 20 and 25 Gy-treated groups showed subsequent continuous increase. At day 7 post-irradiation, except for cTnT, cardiomyocyte function gene levels increased with increasing irradiation dose, but uniquely peaked at 25–30 Gy. Altogether, high-dose irradiation immediately and reversibly modifies the electrical conduction of cardiomyocytes. Thus, compensatory mechanisms at the cellular level may be activated after the high-dose irradiation acute effects, thereby, contributing to the immediate antiarrhythmic outcome of cardiac radioablation for refractory ventricular arrhythmias.

scholarly journals Radiation-Induced Reactions in The Liver — Modulation of Radiation Effects by Lifestyle-Related Factors —

2018 ◽  
Vol 19 (12) ◽  
pp. 3855 ◽  
Author(s):  
Tetsuo Nakajima ◽  
Yasuharu Ninomiya ◽  
Mitsuru Nenoi
Keyword(s):  
Radiation Effects ◽  
Animal Experiments ◽  
High Dose ◽  
Acute Effects ◽  
Related Factors ◽  
Dose Irradiation ◽  
Important Concern ◽  
Radiation Induced ◽  
Effects Of Radiation ◽  
High Calorie

Radiation has a wide variety of effects on the liver. Fibrosis is a concern in medical fields as one of the acute effects of high-dose irradiation, such as with cancer radiotherapies. Cancer is also an important concern following exposure to radiation. The liver has an active metabolism and reacts to radiations. In addition, effects are modulated by many environmental factors, such as high-calorie foods or alcohol beverages. Adaptations to other environmental conditions could also influence the effects of radiation. Reactions to radiation may not be optimally regulated under conditions modulated by the environment, possibly leading to dysregulation, disease or cancer. Here, we introduce some reactions to ionizing radiation in the liver, as demonstrated primarily in animal experiments. In addition, modulation of radiation-induced effects in the liver due to factors such as obesity, alcohol drinking, or supplements derived from foods are reviewed. Perspectives on medical applications by modulations of radiation effects are also discussed.

TL dosimetry of natural quartz sensitized by heat-treatment and high dose irradiation

2008 ◽  
Vol 43 (2-6) ◽  
pp. 487-491 ◽  
Author(s):  
H.J. Khoury ◽  
P.L. Guzzo ◽  
L.B.F. Souza ◽  
T.M.B. Farias ◽  
S. Watanabe
Keyword(s):  
Heat Treatment ◽  
High Dose ◽  
Natural Quartz ◽  
Dose Irradiation

Component analysis reveals sharp tuning of the local field potential in the guinea pig auditory cortex

2013 ◽  
Vol 109 (1) ◽  
pp. 261-272 ◽  
Author(s):  
Alain de Cheveigné ◽  
Jean-Marc Edeline ◽  
Quentin Gaucher ◽  
Boris Gourévitch
Keyword(s):  
Auditory Cortex ◽  
Local Field ◽  
Receptive Fields ◽  
Field Potential ◽  
Component Analysis ◽  
Electrode Arrays ◽  
Linear Combinations ◽  
Spectrotemporal Receptive Fields ◽  
Analysis Technique ◽  
Channel Electrode

Local field potentials (LFPs) recorded in the auditory cortex of mammals are known to reveal weakly selective and often multimodal spectrotemporal receptive fields in contrast to spiking activity. This may in part reflect the wider “listening sphere” of LFPs relative to spikes due to the greater current spread at low than high frequencies. We recorded LFPs and spikes from auditory cortex of guinea pigs using 16-channel electrode arrays. LFPs were processed by a component analysis technique that produces optimally tuned linear combinations of electrode signals. Linear combinations of LFPs were found to have sharply tuned responses, closer to spike-related tuning. The existence of a sharply tuned component implies that a cortical neuron (or group of neurons) capable of forming a linear combination of its inputs has access to that information. Linear combinations of signals from electrode arrays reveal information latent in the subspace spanned by multichannel LFP recordings and are justified by the fact that the observations themselves are linear combinations of neural sources.

scholarly journals Acute effects of low and high dose alcohol on smoking lapse behavior in a laboratory analogue task

2014 ◽  
Vol 231 (24) ◽  
pp. 4649-4657 ◽  
Author(s):  
Christopher W. Kahler ◽  
Jane Metrik ◽  
Nichea S. Spillane ◽  
Anne Day ◽  
Adam M. Leventhal ◽  
...  
Keyword(s):  
High Dose ◽  
Acute Effects ◽  
Smoking Lapse ◽  
Laboratory Analogue ◽  
Lapse Behavior

Response of Bone Subjected to Optimized High Dose Irradiation

2008 ◽  
Vol 24 (5) ◽  
pp. 387-400 ◽  
Author(s):  
H. Wilson Burgess ◽  
James Mackrell ◽  
Derek Toms ◽  
Anuradha Karunanidhi ◽  
Swaroopa Vaidya ◽  
...  
Keyword(s):  
High Dose ◽  
Dose Irradiation

Improved cellular automata model shows that indirect apoptotic cell death due to vascular damage enhances the local control of tumors by single fraction high-dose irradiation

2021 ◽  
Author(s):  
Daisuke Kawahara ◽  
Yasushi Nagata ◽  
Yoichi Watanabe
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Radiation Damage ◽  
Apoptotic Cell ◽  
Vascular Damage ◽  
High Dose ◽  
Oxygen Level ◽  
Cellular Automata Model ◽  
Apoptotic Death ◽  
Dose Irradiation

Abstract We investigated the effects of indirect apoptotic cell death due to vascular damage on tumor response to a single large dose with an improved two-dimensional cellular automata model. The tumor growth was simulated by considering the oxygen and nutrients supplied to the tumor through the blood vessels. The cell damage processes were modeled by taking account of the direct cell death and the indirect death due to the radiation-induced vascular damages. The radiation increased the permeation of oxygen and nutrients through the blood vessel or caused the breakdown of the vasculature. The amount of oxygen in cancer cells affected the response of cancer cells to radiation and the tumor growth rate after irradiation. The lack of oxygen led to the apoptotic death of cancer cells. We calculated the tumor control probability (TCP) at different radiation doses, D, the probability of apoptotic death, PO2_ap, the threshold of the oxygen level for indirect apoptotic death, O2t, the average oxygen level in cancer cells, [O2]av, and the vessel survival probability after radiation damage, Pv. Due to the vessel damage, indirect cell death led to a 4% increase in TCP for the dose ranging from 15 Gy to 20 Gy. TCP increased with increasing PO2_ap and O2t due to increased apoptotic death. The variation of TCP as a function of [O2]av exhibited the minimum at [O2]av of 2.7%. The apoptosis increased as [O2]av decreased, leading to an increasing TCP. On the other hand, the direct radiation damage increased, and the apoptosis decreased for higher [O2]av, resulting in a higher TCP. We showed by modeling the radiation damage of blood vessels in a 2D CA simulation that the indirect apoptotic death of cancer cells, caused by the reduction of the oxygen level due to vascular damage after high dose irradiation, increased TCP.

scholarly journals Neutron/gamma discrimination enhancement: plastic scintillators high dose irradiation and recovery time

2018 ◽  
Vol 170 ◽  
pp. 01011
Author(s):  
Eva Montbarbon ◽  
Matthieu Hamel ◽  
Dominique Tromson ◽  
Marie-Noëlle Amiot ◽  
Camille Frangville ◽  
...  
Keyword(s):  
Recovery Time ◽  
High Dose ◽  
Dose Irradiation ◽  
Plastic Scintillators

scholarly journals Necrotizing myopathy presenting as congestive heart failure and life-threatening ventricular arrhythmias: a case report

2021 ◽  
Vol 5 (6) ◽  
Author(s):  
Kyunghee Lim ◽  
Jong Sung Park ◽  
Byeol-A Yoon ◽  
Song-Hee Han
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Ventricular Arrhythmias ◽  
High Dose ◽  
Respiratory Impairment ◽  
Motor Weakness ◽  
High Dose Steroid ◽  
Necrotizing Autoimmune Myopathy ◽  
Life Threatening ◽  
Autoimmune Myopathy

Abstract Background Necrotizing autoimmune myopathy is a rare subtype of idiopathic inflammatory myopathy; however, it can be associated with fatal cardiac manifestations. Case summary A 58-year-old female patient was referred for congestive heart failure with dysrhythmia. Electrocardiograms showed ventricular arrhythmias of various QRS complex morphologies and coupling intervals with beat-to-beat differences. Despite optimal medical therapy for heart failure, the patient was admitted for the progression of dyspnoea and generalized motor weakness. The burden of non-sustained ventricular tachycardia gradually increased, and ventricular fibrillation eventually occurred. In view of a differential diagnosis of an inflammatory myocardial diseases such as sarcoidosis, a cardiac biopsy was performed. However, pathologic examinations revealed only necrotic muscle fibres without granuloma. Further examinations revealed proximal dominant motor weakness, an elevated serum creatinine-phosphokinase level, myogenic potentials on needle electromyography, and biceps muscle biopsy findings that were compatible with necrotizing autoimmune myopathy. High-dose steroid therapy improved the patient’s motor weakness, including her respiratory impairment, and successfully suppressed ventricular arrhythmias. Discussion This case suggests that intensive immunosuppressive therapy with high-dose steroid could be useful in the necrotizing autoimmune myopathy manifested as congestive heart failure and life-threatening ventricular arrhythmias.

scholarly journals Strain/Damage in Crystalline Materials Bombarded by MeV Ions: Recrystallization of GaAs by High-Dose Irradiation

1984 ◽  
Vol 35 ◽  
Author(s):  
C. R. Wie ◽  
T. Vreeland ◽  
T. A. Tombrello
Keyword(s):  
Surface Layer ◽  
Energy Loss ◽  
Ion Irradiation ◽  
Stopping Power ◽  
High Dose ◽  
Double Crystal ◽  
Saturation Phenomenon ◽  
Nuclear Stopping ◽  
X Ray ◽  
Dose Irradiation

ABSTRACTMeV ion irradiation effects on semiconductor crystals, GaAs(100) and Si (111) and on an insulating crystal CaF2 (111) have been studied by the x-ray rocking curve technique using a double crystal x-ray diffractometer. The results on GaAs are particularly interesting. The strain developed by ion irradiation in the surface layers of GaAs (100) saturates to a certain level after a high dose irradiation (typically 1015/cm2), resulting in a uniform lattice spacing about 0.4% larger than the original spacing of the lattice planes parallel to the surface. The layer of uniform strain corresponds in depth to the region where electronic energy loss is dominant over nuclear collision energy loss. The saturated strain level is the same for both p-type and n-type GaAs. In the early stages of irradiation, the strain induced in the surface is shown to be proportional to the nuclear stopping power at the surface and is independent of electronic stopping power. The strain saturation phenomenon in GaAs is discussed in terms of point defect saturation in the surface layer.An isochronal (15 min.) annealing was done on the Cr-doped GaAs at temperatures between 200° C and 700° C. The intensity in the diffraction peak from the surface strained layer jumps at 200° C < T ≤ 300° C. The strain decreases gradually with temperature, approaching zero at T ≤ 500° C.The strain saturation phenomenon does not occur in the irradiated Si. The strain induced in Si is generally very low (less than 0.06%) and is interpreted to be mostly in the layers adjacent to the maximum nuclear stopping region, with zero strain in the surface layer. The data on CaF2 have been analysed with a kinematical x-ray diffraction theory to get quantitative strain and damage depth profiles for several different doses.

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