Journal: bioRxiv

Article Title: Classifying drugs by their arrhythmogenic risk using machine learning

doi: 10.1101/545863

Figure Lengend Snippet: We characterize calcium transients in ventricular cardiomyocytes in response to drugs, both computationally (top) and experimentally (bottom) and identify the ion channels that most likely generate early afterdepolarizations (left). We then screen the concentration space of the two most relevant channels and identify the classification boundary between the arrhythmic and non-arrhythmic domains using high performance computing and machine learning (center). We validate our approach using electrocardiograms, both computationally and experimentally, in whole heart simulations and isolated Langendorff perfused hearts (right). We demonstrate the potential of our new classifier by risk stratifying 23 common drugs and comparing the result against the reported risk categories of these compounds.

Article Snippet: We excised the hearts from anesthetized rats (2.5% isoflurane in 95% oxygen and 5% carbon dioxide), immediately cannulated the aorta, connected it to a constant pressure perfusion Langendorff system (Harvard Apparatus, Massachusetts) with Krebs solution (118mM NaCl, 4.75mM KCl, 25mM NaHCO 3 , 1.2mM KH 2 PO 4 , 1.2mM MgSO 4 , 1.5mM CaCl 2 , 11mM glucose, and 2mM Pyruvate), warmed to 37° C, and bubbled with 95% oxygen and 5% carbon dioxide.

Techniques: Concentration Assay, Isolation

Journal: PLoS ONE

Article Title: Acute, Delayed and Chronic Remote Ischemic Conditioning Is Associated with Downregulation of mTOR and Enhanced Autophagy Signaling

doi: 10.1371/journal.pone.0111291

Figure Lengend Snippet: Control groups 1, 3 and 5 were left untreated and underwent handling alone without RIC. Treatment groups 2, 4, and 6 underwent RIC via four cycles of 5 min of femoral artery occlusion, followed by 5 min of reperfusion. Following the treatment protocol, mouse hearts were removed (denoted by *), mounted on a isovolumic Langendorff perfusion apparatus, and subjected to 20 min of equilibration, 30 min of no-flow global ischemia and 60 min of reperfusion. The infarcted area was visualized using TTC following global ischemia in each group.

Article Snippet: Isolated hearts were mounted on the Langendorff perfusion apparatus (Radnoti Technologies Inc., Monrovia, CA, USA), and perfused under non-recirculating conditions at a constant pressure of 80 mmHg with 37°C Krebs–Henseleit buffer (KHB) (consisting of the following in mmol/L: NaCl 120.0, NaHCO 3 25.0, KCl 4.7, MgSO 4 1.2, KH 2 PO 4 1.2, CaCl 2 2.5, EDTA 0.5 and glucose 15).

Techniques: Control

Journal: Frontiers in Cardiovascular Medicine

Article Title: Muscarinic receptor regulation of chronic pain-induced atrial fibrillation

doi: 10.3389/fcvm.2022.934906

Figure Lengend Snippet: The measurement of electrophysiological characteristics in the Langendorff perfusion model in sham and pain groups.

Article Snippet: Then, the heart was quickly transferred and attached to the Langendorff perfusion apparatus (Radnoti, BIOPRBE), by which the aorta was continuously perfused with K-H solution, filtered by 5-μm filters, and warmed to 37°C by a water jacket and circulator, at a rate of 2.5 ml/min.

Techniques:

Journal:

Article Title: Properties of New, Long Wavelength, Voltage-Sensitive Dyes in the Heart

doi: 10.1007/s00232-005-0826-8

Figure Lengend Snippet: APs and Cai transients were mapped simultaneously from Langendorff perfused hearts that were stained with both PGH I and Rhod-2 by focusing images of the heart on 2 16×16 elements photodiode arrays (Choi et al., 2002; Choi & Salama, 2000).

Article Snippet: Action Spectra Frog hearts were isolated and perfused in a Langendorff apparatus by cannulating the Cordis bulbus with a Tyrode’s solution containing (in mM): 116 NaCl, 3 KCL, 1 MgCl 2 , 10 Hepes, 5 Glucose, 1 CaCl 2 , pH 7.6–7.8, at 23 °C.

Techniques: Staining

Journal: Acta Physiologica (Oxford, England)

Article Title: Hypoxia exposure and B‐type natriuretic peptide release from Langendorff heart of rats

doi: 10.1111/apha.12767

Figure Lengend Snippet: Langendorff measurement set‐up. (a) Whole system, (b) enlargement from a (red rectangle) showing details of the oxygen level measurements before the heart (an arrow shows the probe) and heart chamber and (c) enlargement from b (yellow rectangle) showing the chamber that was used to measure the oxygen level of coronary flow (an arrow shows the probe) and collect samples from the flow. Coronary flow was dripping to the chamber equipped with the oxygen probe, and after recording the oxygen level, the coronary flow entered into a collecting tube, which made it possible to analyse samples from the coronary flow.

Article Snippet: After removal of the heart, the ascending aorta was connected into Langendorff heart perfusion apparatus (Radnoti Working Heart System, Monrovia, CA, USA) and was subjected to retrograde perfusion with a physiological Krebs–Henseleit solution (NaCl 115 m m , KCl 4.6 m m , KH 2 PO 4 1.2 m m , MgSO 4 1.2 m m , CaCl 2 2.5 m m , NaHCO 3 25 m m and glucose 11 m m ) equilibrated with carbogen gas (95% oxygen and 5% carbon dioxide) to a pH of 7.4.

Techniques:

Journal: Acta Physiologica (Oxford, England)

Article Title: Hypoxia exposure and B‐type natriuretic peptide release from Langendorff heart of rats

doi: 10.1111/apha.12767

Figure Lengend Snippet: (a) BNP concentration in coronary flow, (b) oxygen removal from perfusate and (c) heart rate in the Langendorff rat heart when the oxygen concentration was decreased with N 2 gassing (hypoxia group; , n = 7), controls (♦, n = 5). Oxygen was measured with an optical oxygen probe before and after the heart during perfusion. *Denotes a significant difference ( P < 0.05) between hypoxia treatment and controls, while ¤ indicates a significant difference ( P < 0.05) within a hypoxia group as compared to the starting value. Two‐way repeated‐measures anova followed by Holm–Sidak test was used. The values are mean ± SE .

Article Snippet: After removal of the heart, the ascending aorta was connected into Langendorff heart perfusion apparatus (Radnoti Working Heart System, Monrovia, CA, USA) and was subjected to retrograde perfusion with a physiological Krebs–Henseleit solution (NaCl 115 m m , KCl 4.6 m m , KH 2 PO 4 1.2 m m , MgSO 4 1.2 m m , CaCl 2 2.5 m m , NaHCO 3 25 m m and glucose 11 m m ) equilibrated with carbogen gas (95% oxygen and 5% carbon dioxide) to a pH of 7.4.

Techniques: Concentration Assay