The Noninvasive Electrical Mapping of Reanimated Large Mammalian Hearts

2020 ◽  
Author(s):  
Renee C. Brigham ◽  
David A. Ramirez ◽  
Tinen L. Iles ◽  
Paul A. Iaizzo
Keyword(s):  
Ex Vivo ◽  
Epicardial Mapping ◽  
Critical Data ◽  
Non Invasive ◽  
Mapping System ◽  
Set Up ◽  
Perfused Hearts ◽  
Mapping Systems

Abstract Electroanatomical mapping systems are being utilized clinically for locating arrhythmias within a given patient’s heart. Today, employed endocardial mapping systems are invasive and require extensive set-up time. Epicardial mapping systems, like CardioInsight™ from Medtronic, are non-invasive but require co-registration of electrodes to the heart, e.g. via a required Computed Tomography (CT) scan. This system has been used both clinically and in several laboratories in situ. The difficulties with in vitro uses are that the ex vivo perfused hearts lack an associated thoracic cavity, resulting in the possibility of inconsistent placement of electrodes, and poor conduction of epicardial signals. We are developing in our laboratory means to use the CardioInsight™ system on reanimated large mammalian hearts. Preliminary studies were conducted on swine hearts, but this system could be also be utilized with reanimated human hearts, making this research even more translatable. The use of this epicardial mapping system will allow for critical observations during pacing or ablation experiments and for collecting critical data for computational modeling.

scholarly journals Antagonism of Adherent Invasive E. coli LF82 With Human α-defensin 5 in the Follicle-associated Epithelium of Patients With Ileal Crohn’s Disease

2020 ◽  
Author(s):  
Lina Y Alkaissi ◽  
Martin E Winberg ◽  
Stéphanie DS Heil ◽  
Staffan Haapaniemi ◽  
Pär Myrelid ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Ex Vivo ◽  
Ussing Chambers ◽  
E Coli ◽  
Follicle Associated Epithelium ◽  
Vitro Model ◽  
Set Up

Abstract Background The first visible signs of Crohn’s disease (CD) are microscopic erosions over the follicle-associated epithelium (FAE). The aim of the study was to investigate the effects of human α-defensin 5 (HD5) on adherent-invasive Escherichia coli LF82 translocation and HD5 secretion after LF82 exposure in an in vitro model of human FAE and in human FAE ex vivo. Methods An in vitro FAE-model was set up by the coculture of Raji B cells and Caco-2-cl1 cells. Ileal FAE from patients with CD and controls were mounted in Ussing chambers. The effect of HD5 on LF82 translocation was studied by LF82 exposure to the cells or tissues with or without incubation with HD5. The HD5 secretion was measured in human FAE exposed to LF82 or Salmonella typhimurium. The HD5 levels were evaluated by immunofluorescence, immunoblotting, and ELISA. Results There was an increased LF82 translocation across the FAE-model compared with Caco-2-cl1 (P < 0.05). Incubation of cell/tissues with HD5 before LF82 exposure reduced bacterial passage in both models. Human FAE showed increased LF82 translocation in CD compared with controls and attenuated passage after incubation with sublethal HD5 in both CD and controls (P < 0.05). LF82 exposure resulted in a lower HD5 secretion in CD FAE compared with controls (P < 0.05), whereas Salmonella exposure caused equal secretion on CD and controls. There were significantly lower HD5 levels in CD tissues compared with controls. Conclusions Sublethal HD5 reduces the ability of LF82 to translocate through FAE. The HD5 is secreted less in CD in response to LF82, despite a normal response to Salmonella. This further implicates the integrated role of antimicrobial factors and barrier function in CD pathogenesis.

scholarly journals Generation of vascular chimerism within donor organs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shahar Cohen ◽  
Shirly Partouche ◽  
Michael Gurevich ◽  
Vladimir Tennak ◽  
Vadym Mezhybovsky ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Patient Specific ◽  
Machine Perfusion ◽  
Organ Perfusion ◽  
Perfusion Process ◽  
Hind Limbs ◽  
Porcine Organs ◽  
Immunological Barrier

AbstractWhole organ perfusion decellularization has been proposed as a promising method to generate non-immunogenic organs from allogeneic and xenogeneic donors. However, the ability to recellularize organ scaffolds with multiple patient-specific cells in a spatially controlled manner remains challenging. Here, we propose that replacing donor endothelial cells alone, while keeping the rest of the organ viable and functional, is more technically feasible, and may offer a significant shortcut in the efforts to engineer transplantable organs. Vascular decellularization was achieved ex vivo, under controlled machine perfusion conditions, in various rat and porcine organs, including the kidneys, liver, lungs, heart, aorta, hind limbs, and pancreas. In addition, vascular decellularization of selected organs was performed in situ, within the donor body, achieving better control over the perfusion process. Human placenta-derived endothelial progenitor cells (EPCs) were used as immunologically-acceptable human cells to repopulate the luminal surface of de-endothelialized aorta (in vitro), kidneys, lungs and hind limbs (ex vivo). This study provides evidence that artificially generating vascular chimerism is feasible and could potentially pave the way for crossing the immunological barrier to xenotransplantation, as well as reducing the immunological burden of allogeneic grafts.

In-vitro, ex-vivo, and in-vivo release evaluation of in situ forming buprenorphine implants using mixture of PLGA copolymers and additives

2018 ◽  
Vol 68 (16) ◽  
pp. 965-977 ◽  
Author(s):  
Hossein Kamali ◽  
Elham Khodaverdi ◽  
Farzin Hadizadeh ◽  
Seyed Ahmad Mohajeri ◽  
Younes Kamali ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Situ Forming ◽  
In Vivo Release

DEVELOPMENT AND EVALUATION OF NANOPARTICULATE BASED IN-SITU GELLING SYSTEM FOR NASAL DRUG DELIVERY OF AN ANTI-EPILEPTIC DRUG

INDIAN DRUGS ◽  
2017 ◽  
Vol 54 (09) ◽  
pp. 83-85
Author(s):  
A Ambavkar ◽  
◽  
N. Desai
Keyword(s):  
Drug Release ◽  
Ex Vivo ◽  
Entrapment Efficiency ◽  
Poloxamer 407 ◽  
Nasal Drug Delivery ◽  
Anti Epileptic Drug ◽  
Nanolipid Carriers ◽  
In Situ Nasal Gel

The objective of the study was to develop and evaluate nanolipid carriers based in situ gel of Carbamazepine, for brain delivery through intranasal route. The non – invasive nasal route can provide rapid delivery of drugs directly to the central nervous system by bypassing the blood brain barrier. The nanolipid carriers of carbamazepine as in situ nasal gel can prolong the drug release for control of repetitive seizures and were prepared by Phase Inversion Temperature technique. The retention of the carriers in the nasal cavity was improved by using Poloxamer 407 as thermoresponsive and Carbopol 974P as mucoadhesive gelling polymers, respectively. The developed gel was evaluated for particle size, polydispersity index, zeta potential, morphology, entrapment efficiency, mucoadhesive and thermoresponsive behaviour, in vitro drug release, ex vivo permeation and nasociliotoxicity. The gel showed sustained release over prolonged periods and was found to be non-toxic to the sheep nasal mucosa.

scholarly journals An in-vitro assay using human spermatozoa to detect toxicity of biologically active substances

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tino Vollmer ◽  
Börje Ljungberg ◽  
Vera Jankowski ◽  
Joachim Jankowski ◽  
Griet Glorieux ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Toxicity Testing ◽  
Biologically Active ◽  
Human Spermatozoa ◽  
Vitro Assay ◽  
Cellular Behavior ◽  
Novel Method ◽  
Set Up

Abstract Identifying the key toxic players within an in-vivo toxic syndrome is crucial to develop targeted therapies. Here, we established a novel method that characterizes the effect of single substances by means of an ex-vivo incubation set-up. We found that primary human spermatozoa elicit a distinct motile response on a (uremic) toxic milieu. Specifically, this approach describes the influence of a bulk toxic environment (uremia) as well as single substances (uremic toxins) by real-time analyzing motile cellular behavior. We established the human spermatozoa-based toxicity testing (HSTT) for detecting single substance-induced toxicity to be used as a screening tool to identify in-vivo toxins. Further, we propose an application of the HSTT as a method of clinical use to evaluate toxin-removing interventions (hemodialysis).

Preparation of levofloxacin loaded in situ gel for sustained ocular delivery: in vitro and ex vivo evaluations

2019 ◽  
Vol 46 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Pooja Jain ◽  
Chandra Prakash Jaiswal ◽  
Mohd. Aamir Mirza ◽  
Md. Khalid Anwer ◽  
Zeenat Iqbal
Keyword(s):  
Ex Vivo ◽  
Ocular Delivery ◽  
In Situ Gel

scholarly journals DEVELOPMENT AND EVALUATION OF A POLOXAMER- AND CHITOSAN-BASED IN SITU GEL-FORMING INJECTABLE DEPOT

2020 ◽  
pp. 36-41
Author(s):  
Hema a Nair ◽  
NAZIA BEGUM
Keyword(s):  
Ex Vivo ◽  
Gelation Time ◽  
In Vitro Release ◽  
Aqueous Acetic Acid ◽  
Drug Content ◽  
Low Viscosity ◽  
Model Drug ◽  
Dialysis Bag

Objective: The present study is intended to investigate the applicability of poloxamer- and chitosan-based temperature induced in situ injectable gelling depot for once a week therapy as an intramuscular injection employing olanzapine as a model drug. Methods: The thermosetting gel was prepared by admixture of a solution of poloxamer P127 and a solution of olanzapine and chitosan in aqueous acetic acid. The resultant formulation was characterized for gelation temperature, gelation time, viscosity, syringeability, pH, drug content, and in vitro drug release. The in vitro release of olanzapine from the gelled depot was followed using USP paddle type II apparatus in conjunction with a dialysis bag. The gel was injected ex vivo into chicken muscle and observed by subsequent dissection. Results: The formulation was designed to have a phase transition temperature of 34°C and gelled in <10 s at 37°C. Addition of chitosan imparted favorable rheological properties to the poloxamer gel and resulted in a pseudoplastic mixture with low viscosity in the sol state and higher viscosity post gelation. The preparation had a pH of 5.4, appropriate drug content and readily passed through a 20 gauge needle. The release of olanzapine was unhindered by the dialysis bag. Following an initial bust, a sustained, zero-order release of the remainder of drug was observed up to 9 days. The injectable was found to form a compact depot when evaluated ex vivo. Conclusion: The developed system showed several features which make it a suitable vehicle for sustained intramuscular delivery of drugs.

scholarly journals Measurement and analysis of sarcomere length in rat cardiomyocytes in situ and in vitro

2010 ◽  
Vol 298 (5) ◽  
pp. H1616-H1625 ◽  
Author(s):  
G. Bub ◽  
P. Camelliti ◽  
C. Bollensdorff ◽  
D. J. Stuckey ◽  
G. Picton ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Sarcomere Length ◽  
Ex Vivo ◽  
Living Cells ◽  
Perfused Heart ◽  
Experimental Conditions ◽  
Rat Cardiomyocytes ◽  
Two Photon

Sarcomere length (SL) is an important determinant and indicator of cardiac mechanical function; however, techniques for measuring SL in living, intact tissue are limited. Here, we present a technique that uses two-photon microscopy to directly image striations of living cells in cardioplegic conditions, both in situ (Langendorff-perfused rat hearts and ventricular tissue slices, stained with the fluorescent marker di-4-ANEPPS) and in vitro (acutely isolated rat ventricular myocytes). Software was developed to extract SL from two-photon fluorescence image sets while accounting for measurement errors associated with motion artifact in raster-scanned images and uncertainty of the cell angle relative to the imaging plane. Monte-Carlo simulations were used to guide analysis of SL measurements by determining error bounds as a function of measurement path length. The mode of the distribution of SL measurements in resting Langendorff-perfused heart is 1.95 μm ( n = 167 measurements from N = 11 hearts) after correction for tissue orientation, which was significantly greater than that in isolated cells (1.71 μm, n = 346, N = 9 isolations) or ventricular slice preparations (1.79 μm, n = 79, N = 3 hearts) under our experimental conditions. Furthermore, we find that edema in arrested Langendorff-perfused heart is associated with a mean SL increase; this occurs as a function of time ex vivo and correlates with tissue volume changes determined by magnetic resonance imaging. Our results highlight that the proposed method can be used to monitor SL in living cells and that different experimental models from the same species may display significantly different SL values under otherwise comparable conditions, which has implications for experiment design, as well as comparison and interpretation of data.

Sister Chromatid Exchanges in Cultured Amniocytes Exposed to Diagnostic Ultrasound in Vitro

1994 ◽  
Vol 35 (1) ◽  
pp. 58-61
Author(s):  
B. Porfirio ◽  
B. Dallapiccola ◽  
C. Cittantl ◽  
P. Colamussi ◽  
M. Giganti ◽  
...  
Keyword(s):  
Sister Chromatid ◽  
Diagnostic Ultrasound ◽  
Sister Chromatid Exchanges ◽  
In Vitro System ◽  
Array Transducer ◽  
Effect Of Treatment ◽  
Set Up ◽  
Chromatid Exchanges

An in vitro system has been set up to study the possible genetic effects of diagnostic ultrasound (US) on the developing fetus. Amniotic cells were cultured by the in situ technique. Well established clones were exposed to US for various lengths of time using a linear array transducer within a sound transparent apparatus. Cells were then grown in the presence of 5-bromo-2'-deoxyuridine and processed for scoring the number of sister chromatid exchanges (SCE) as the cytogenetic endpoint. There was no linear relationship between the SCE frequency and the duration of US exposure. Variance analysis showed that only interindividual variability was a significant component of total variation. Neither the main effect of treatment nor the interaction effect were statistically significant. The data suggest that US delivered from a diagnostic unit to actively growing cultured fetal cells in a system closely mimicking the conditions of US exposure during amniocentesis does not induce SCE.

In vitro and ex vivo characterisation of an in situ gelling formulation for sustained lidocaine release with potential use following knee arthroplasty

2018 ◽  
Vol 8 (3) ◽  
pp. 820-829 ◽  
Author(s):  
Manisha Sharma ◽  
Kaushik Chandramouli ◽  
Louise Curley ◽  
Beau Pontre ◽  
Keryn Reilly ◽  
...  
Keyword(s):  
Knee Arthroplasty ◽  
Ex Vivo ◽  
In Situ Gelling ◽  
Potential Use
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