scholarly journals Brain Tissue Conductivity Measurements with MR-Electrical Properties Tomography: An In Vivo Study

2020 ◽  
Author(s):  
Stefano Mandija ◽  
Petar I. Petrov ◽  
Jord J. T. Vink ◽  
Sebastian F. W. Neggers ◽  
Cornelis A. T. van den Berg
Keyword(s):  
Electrical Properties ◽  
Healthy Subjects ◽  
Ex Vivo ◽  
Simulated Data ◽  
Ground Truth ◽  
In Vivo Study ◽  
Conductivity Measurements ◽  
Tissue Conductivity ◽  
Before And After

AbstractFirst in vivo brain conductivity reconstructions using Helmholtz MR-Electrical Properties Tomography (MR-EPT) have been published. However, a large variation in the reconstructed conductivity values is reported and these values differ from ex vivo conductivity measurements. Given this lack of agreement, we performed an in vivo study on eight healthy subjects to provide reference in vivo brain conductivity values. MR-EPT reconstructions were performed at 3 T for eight healthy subjects. Mean conductivity and standard deviation values in the white matter, gray matter and cerebrospinal fluid (σWM, σGM, and σCSF) were computed for each subject before and after erosion of regions at tissue boundaries, which are affected by typical MR-EPT reconstruction errors. The obtained values were compared to the reported ex vivo literature values. To benchmark the accuracy of in vivo conductivity reconstructions, the same pipeline was applied to simulated data, which allow knowledge of ground truth conductivity. Provided sufficient boundary erosion, the in vivo σWM and σGM values obtained in this study agree for the first time with literature values measured ex vivo. This could not be verified for the CSF due to its limited spatial extension. Conductivity reconstructions from simulated data verified conductivity reconstructions from in vivo data and demonstrated the importance of discarding voxels at tissue boundaries. The presented σWM and σGM values can therefore be used for comparison in future studies employing different MR-EPT techniques.

scholarly journals Encapsulated cyclosporine does not change the composition of the human microbiota when assessed ex vivo and in vivo

2020 ◽  
Vol 69 (6) ◽  
pp. 854-863
Author(s):  
Catherine O'Reilly ◽  
Órla O’Sullivan ◽  
Paul D. Cotter ◽  
Paula M. O’Connor ◽  
Fergus Shanahan ◽  
...  
Keyword(s):  
Pilot Study ◽  
Gut Microbiota ◽  
Targeted Delivery ◽  
Healthy Subjects ◽  
Ex Vivo ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Microbiota Composition ◽  
Faecal Samples

Introduction. Management of steroid-refractory ulcerative colitis has predominantly involved treatment with systemic cyclosporine A (CyA) and infliximab. Aim. The purpose of this study was to assess the effect of using a colon-targeted delivery system CyA formulation on the composition and functionality of the gut microbiota. Methodology. Ex vivo faecal fermentations from six healthy control subjects were treated with coated minispheres (SmPill) with (+) or without (−) CyA and compared with a non-treated control in a model colon system. In addition, the in vivo effect of the SmPill+CyA formulation was investigated by analysing the gut microbiota in faecal samples collected before the administration of SmPill+CyA and after 7 consecutive days of administration from eight healthy subjects who participated in a pilot study. Results. Analysis of faecal samples by 16S rRNA gene sequencing indicated little variation in the diversity or relative abundance of the microbiota composition before or after treatment with SmPill minispheres with or without CyA ex vivo or with CyA in vivo. Short-chain fatty acid profiles were evaluated using gas chromatography, showing an increase in the concentration of n-butyrate (P=0.02) and acetate (P=0.32) in the faecal fermented samples incubated in the presence of SmPill minispheres with or without CyA. This indicated that increased acetate and butyrate production was attributed to a component of the coated minispheres rather than an effect of CyA on the microbiota. Butyrate and acetate levels also increased significantly (P=0.05 for both) in the faecal samples of healthy individuals following 7 days’ treatment with SmPill+CyA in the pilot study. Conclusion. SmPill minispheres with or without CyA at the clinically relevant doses tested here have negligible direct effects on the gut microbiota composition. Butyrate and acetate production increased, however, in the presence of the beads in an ex vivo model system as well as in vivo in healthy subjects. Importantly, this study also demonstrates the relevance and value of using ex vivo colon models to predict the in vivo impact of colon-targeted drugs directly on the gut microbiota.

Assessment of the osteogenic potential of alendronate on isolated adipose-derived stem cells: An ex-vivo and in-vivo study

2015 ◽  
Vol 10 (1) ◽  
pp. 32
Author(s):  
MarwaM Ellithy ◽  
MohamedS Ayoub ◽  
EffatA Abbas ◽  
MohamedA Abd El Hamid ◽  
HouryM Baghdadi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ex Vivo ◽  
In Vivo Study ◽  
Osteogenic Potential ◽  
Adipose Derived Stem Cells

scholarly journals Influence of extracorporeal membrane oxygenation on the pharmacokinetics of ceftolozane/tazobactam: an ex vivo and in vivo study

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Camille Mané ◽  
Clément Delmas ◽  
Jean Porterie ◽  
Géraldine Jourdan ◽  
Patrick Verwaerde ◽  
...  
Keyword(s):  
Extracorporeal Membrane Oxygenation ◽  
Ex Vivo ◽  
In Vivo Study ◽  
Membrane Oxygenation

scholarly journals New device permitting non‐invasive reversal of fetal endoscopic tracheal occlusion: ex‐vivo and in‐vivo study

2020 ◽  
Vol 56 (4) ◽  
pp. 522-531 ◽  
Author(s):  
D. Basurto ◽  
N. Sananès ◽  
E. Verbeken ◽  
D. Sharma ◽  
E. Corno ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Vivo Study ◽  
Tracheal Occlusion ◽  
New Device ◽  
Non Invasive

751 Prediction of Colonic Neoplasia Through Spectral Marker Analysis from the Endoscopically Normal Rectum: An Ex Vivo and In Vivo Study

2008 ◽  
Vol 134 (4) ◽  
pp. A-109
Author(s):  
Hemant K. Roy ◽  
Vladimir Turzhitsky ◽  
Andrew Gomes ◽  
Michael J. Goldberg ◽  
Jeremy D. Rogers ◽  
...  
Keyword(s):  
Ex Vivo ◽  
In Vivo Study ◽  
Marker Analysis ◽  
Colonic Neoplasia

scholarly journals In vivo study and thermodynamic investigation of two lanthanum complexes, La(dpp)3 and La(XT), for the treatment of bone resorption disorders

2015 ◽  
Vol 6 (11) ◽  
pp. 6439-6447 ◽  
Author(s):  
J. F. Cawthray ◽  
D. M. Weekes ◽  
O. Sivak ◽  
A. L. Creagh ◽  
F. Ibrahim ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Ex Vivo ◽  
In Vivo Study ◽  
Oral Drug ◽  
Thermodynamic Investigation ◽  
Preventative Measure ◽  
Drug Candidates

Lanthanum could act as a preventative measure against bone resorption disorders; two compounds are thoroughly investigated both in vivo and ex vivo as potential oral drug candidates.

scholarly journals The Diverse Potential of Gluten from Different Durum Wheat Varieties in Triggering Celiac Disease: A Multilevel In Vitro, Ex Vivo and In Vivo Approach

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3566
Author(s):  
Federica Gaiani ◽  
Sara Graziano ◽  
Fatma Boukid ◽  
Barbara Prandi ◽  
Lorena Bottarelli ◽  
...  
Keyword(s):  
Immune Response ◽  
Celiac Disease ◽  
Durum Wheat ◽  
Ex Vivo ◽  
Diet Group ◽  
Control Group ◽  
Wheat Varieties ◽  
Before And After

The reasons behind the increasing prevalence of celiac disease (CD) worldwide are still not fully understood. This study adopted a multilevel approach (in vitro, ex vivo, in vivo) to assess the potential of gluten from different wheat varieties in triggering CD. Peptides triggering CD were identified and quantified in mixtures generated from simulated gastrointestinal digestion of wheat varieties (n = 82). Multivariate statistics enabled the discrimination of varieties generating low impact on CD (e.g., Saragolla) and high impact (e.g., Cappelli). Enrolled subjects (n = 46) were: 19 healthy subjects included in the control group; 27 celiac patients enrolled for the in vivo phase. Celiacs were divided into a gluten-free diet group (CD-GFD), and a GFD with Saragolla-based pasta group (CD-Sar). The diet was followed for 3 months. Data were compared between CD-Sar and CD-GFD before and after the experimental diet, demonstrating a limited ability of Saragolla to trigger immunity, although not comparable to a GFD. Ex vivo studies showed that Saragolla and Cappelli activated immune responses, although with great variability among patients. The diverse potential of durum wheat varieties in triggering CD immune response was demonstrated. Saragolla is not indicated for celiacs, yet it has a limited potential to trigger adverse immune response.

scholarly journals PTH Modulation by Aldosterone and Angiotensin II is Blunted in Hyperaldosteronism and Rescued by Adrenalectomy

2019 ◽  
Vol 104 (9) ◽  
pp. 3726-3734 ◽  
Author(s):  
Livia Lenzini ◽  
Selene Prisco ◽  
Paul Emmanuel Vanderriele ◽  
Silvia Lerco ◽  
Francesca Torresan ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Ex Vivo ◽  
Primary Cultures ◽  
Zona Glomerulosa ◽  
Before And After ◽  
Bilateral Adrenal Hyperplasia ◽  
Aldosterone Producing Adenoma ◽  
Serum Pth

Abstract Context Accumulating evidence suggests a link between adrenocortical zona glomerulosa and parathyroid gland through mechanisms that remain unexplored. Objectives To test the hypothesis that in vivo angiotensin II blockade affects PTH secretion in patients with hypertension and that aldosterone and angiotensim II directly stimulate PTH secretion ex vivo. Design and Setting We investigated the changes of serum PTH levels induced by oral captopril (50 mg) administration in patients with primary essential hypertension (EH) and with primary aldosteronism (PA) caused by bilateral adrenal hyperplasia (BAH) or aldosterone-producing adenoma (APA), the latter before and after adrenalectomy. We also exposed primary cultures of human parathyroid cells from patients with primary hyperparathyroidism to angiotensin II (10−7 M) and/or aldosterone (10−7 M). Results Captopril lowered PTH levels (in nanograms per liter) both in patients with EH (n = 63; 25.9 ± 8.3 baseline vs 24.4 ± 8.0 postcaptopril, P < 0.0001) and in patients with APA after adrenalectomy (n = 27; 26.3 ± 11.6 vs 24.0 ± 9.7 P = 0.021). However, it was ineffective in patients with full-blown PA caused by APA and BAH. In primary culture of human parathyroid cells, both aldosterone (P < 0.001) and angiotensin II (P = 0.002) markedly increased PTH secretion from baseline, by acting through mineralocorticoid receptor and angiotensin type 1 receptor, as these effects were abolished by canrenone and irbesartan, respectively. Conclusion These results collectively suggest an implication of the renin-angiotensin-aldosterone system in PTH regulation in humans, at least in PTH-secreting cells obtained from parathyroid tumors. Moreover, they further support the concept that mild hyperparathyroidism is a feature of human PA that is correctable with adrenalectomy.

scholarly journals Sparse Representation of Deformable 3D Organs with Spherical Harmonics and Structured Dictionary

2011 ◽  
Vol 2011 ◽  
pp. 1-17
Author(s):  
Dan Wang ◽  
Ahmed H. Tewfik ◽  
Yingchun Zhang ◽  
Yunhe Shen
Keyword(s):  
Sparse Representation ◽  
Spherical Harmonic ◽  
Ex Vivo ◽  
Ground Truth ◽  
Maximum Error ◽  
Training Data ◽  
Data Set ◽  
Low Dimensionality ◽  
Reconstructed Surface

This paper proposed a novel algorithm to sparsely represent a deformable surface (SRDS) with low dimensionality based on spherical harmonic decomposition (SHD) and orthogonal subspace pursuit (OSP). The key idea in SRDS method is to identify the subspaces from a training data set in the transformed spherical harmonic domain and then cluster each deformation into the best-fit subspace for fast and accurate representation. This algorithm is also generalized into applications of organs with both interior and exterior surfaces. To test the feasibility, we first use the computer models to demonstrate that the proposed approach matches the accuracy of complex mathematical modeling techniques and then both ex vivo and in vivo experiments are conducted using 3D magnetic resonance imaging (MRI) scans for verification in practical settings. All results demonstrated that the proposed algorithm features sparse representation of deformable surfaces with low dimensionality and high accuracy. Specifically, the precision evaluated as maximum error distance between the reconstructed surface and the MRI ground truth is better than 3 mm in real MRI experiments.

scholarly journals Radiofrequency Thermoablation On Ex Vivo Animal Tissues: Changes on Isolated Swine Thyroids

2021 ◽  
Vol 12 ◽  
Author(s):  
Paola Pregel ◽  
Elisa Scala ◽  
Michela Bullone ◽  
Marina Martano ◽  
Linda Nozza ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Isotonic Saline ◽  
Real Life ◽  
Tissue Conductivity ◽  
Energy Delivery ◽  
Before And After ◽  
Internally Cooled ◽  
Tissue Shrinkage ◽  
Saline Solutions ◽  
Radiofrequency Thermoablation

The use of Radiofrequency thermoablation (RFA) for treating large thyroid nodules is limited by the modest efficiency of the available systems in terms of volume of the ablation zones (AZs). This increases the risk of incomplete ablation of the nodule. Systems employing perfused electrodes have been developed to increase the volume of the AZ. Aim of this study is to compare the size of the AZ induced by RFA systems using internally cooled perfused vs. non-perfused electrodes in swine thyroids. RFAs were performed on 40 freshly isolated swine thyroids using both systems. The perfused system was tested using 0.9% saline, 7% and 18% hypertonic saline solutions. Energy delivery to the tissue was stopped when tissue conductivity dropped (real life simulations) and after an established time of 20 seconds (controlled duration). Following RFA, thyroids were transversally and longitudinally cut. Photographs were taken for macroscopic morphometry of the ablated zones before and after formalin fixation, to evaluate tissue shrinkage. Microscopic morphometry was performed on PAS stained sections. In real life simulation experiments, gross morphometry revealed that AZs produced with electrodes perfused using 7.0% saline are larger compared to isotonic saline. Microscopically, all the conditions tested using the perfused system produced larger AZs compared to non-perfused system after 20 seconds of RFA. In conclusion, the perfusion with 7.0% NaCl solution increased the electrical conductivity of the tissue in real life simulations, resulting in larger ablated areas compared to the use of isotonic saline.

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