About Puncture Testing Applied for Mechanical Characterization of Fetal Membranes

Puncture testing has been applied in several studies for the mechanical characterization of human fetal membrane (FM) tissue, and significant knowledge has been gained from these investigations. When comparing results of mechanical testing (puncture, inflation, and uniaxial tension), we have observed discrepancies in the rupture sequence of FM tissue and significant differences in the deformation behavior. This study was undertaken to clarify these discrepancies. Puncture experiments on FM samples were performed to reproduce previous findings, and numerical simulations were carried out to rationalize particular aspects of membrane failure. The results demonstrate that both rupture sequence and resistance to deformation depend on the samples' fixation. Soft fixation leads to slippage in the clamping, which reduces mechanical loading of the amnion layer and results in chorion rupturing first. Conversely, the stiffer, stronger, and less extensible amnion layer fails first if tight fixation is used. The results provide a novel insight into the interpretation of ex vivo testing as well as in vivo membrane rupture.

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Fluid Structural Analysis of Urine Flow in a Stented Ureter

Computational and Mathematical Methods in Medicine ◽

10.1155/2016/5710798 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

J. Carlos Gómez-Blanco ◽

F. Javier Martínez-Reina ◽

Domingo Cruz ◽

J. Blas Pagador ◽

Francisco M. Sánchez-Margallo ◽

...

Keyword(s):

Computational Models ◽

Mechanical Characterization ◽

Ex Vivo ◽

Biological Tissues ◽

Urine Flow ◽

Computational Environment ◽

Computational Fluid Dynamics Cfd

Many urologists are currently studying new designs of ureteral stents to improve the quality of their operations and the subsequent recovery of the patient. In order to help during this design process, many computational models have been developed to simulate the behaviour of different biological tissues and provide a realistic computational environment to evaluate the stents. However, due to the high complexity of the involved tissues, they usually introduce simplifications to make these models less computationally demanding. In this study, the interaction between urine flow and a double-J stented ureter with a simplified geometry has been analysed. The Fluid-Structure Interaction (FSI) of urine and the ureteral wall was studied using three models for the solid domain: Mooney-Rivlin, Yeoh, and Ogden. The ureter was assumed to be quasi-incompressible and isotropic. Data obtained in previous studies from ex vivo and in vivo mechanical characterization of different ureters were used to fit the mentioned models. The results show that the interaction between the stented ureter and urine is negligible. Therefore, we can conclude that this type of models does not need to include the FSI and could be solved quite accurately assuming that the ureter is a rigid body and, thus, using the more simple Computational Fluid Dynamics (CFD) approach.

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Structural Characterization of Cardiac Ex Vivo Transthyretin Amyloid: Insight into the Transthyretin Misfolding Pathway In Vivo

Biochemistry ◽

10.1021/acs.biochem.0c00091 ◽

2020 ◽

Vol 59 (19) ◽

pp. 1800-1803

Author(s):

Anvesh K. R. Dasari ◽

Ivan Hung ◽

Brian Michael ◽

Zhehong Gan ◽

Jeffery W. Kelly ◽

...

Keyword(s):

Structural Characterization ◽

Ex Vivo ◽

Insight Into

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Characterization of baboon fetal membranes: Evaluation as a non-human primate model of fetal membrane rupture

Journal of the Society for Gynecologic Investigation ◽

10.1016/s1071-5576(97)86699-3 ◽

1998 ◽

Vol 5 (1) ◽

pp. 192A-192A

Author(s):

J MCLAREN ◽

S BELL ◽

A FAALEABAS

Keyword(s):

Fetal Membrane ◽

Fetal Membranes ◽

Primate Model ◽

Membrane Rupture ◽

Fetal Membrane Rupture ◽

Human Primate

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Consequences of SUR2[A478V] Mutation in Skeletal Muscle of Murine Model of Cantu Syndrome

Cells ◽

10.3390/cells10071791 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1791

Author(s):

Rosa Scala ◽

Fatima Maqoud ◽

Nicola Zizzo ◽

Giuseppe Passantino ◽

Antonietta Mele ◽

...

Keyword(s):

Skeletal Muscle ◽

Katp Channel ◽

Ex Vivo ◽

Channel Modulation ◽

Flexor Digitorum Brevis ◽

Inflammatory Edema ◽

Flexor Digitorum ◽

Channel Currents

(1) Background: Cantu syndrome (CS) arises from gain-of-function (GOF) mutations in the ABCC9 and KCNJ8 genes, which encode ATP-sensitive K+ (KATP) channel subunits SUR2 and Kir6.1, respectively. Most CS patients have mutations in SUR2, the major component of skeletal muscle KATP, but the consequences of SUR2 GOF in skeletal muscle are unknown. (2) Methods: We performed in vivo and ex vivo characterization of skeletal muscle in heterozygous SUR2[A478V] (SUR2wt/AV) and homozygous SUR2[A478V] (SUR2AV/AV) CS mice. (3) Results: In SUR2wt/AV and SUR2AV/AV mice, forelimb strength and diaphragm amplitude movement were reduced; muscle echodensity was enhanced. KATP channel currents recorded in Flexor digitorum brevis fibers showed reduced MgATP-sensitivity in SUR2wt/AV, dramatically so in SUR2AV/AV mice; IC50 for MgATP inhibition of KATP currents were 1.9 ± 0.5 × 10−5 M in SUR2wt/AV and 8.6 ± 0.4 × 10−6 M in WT mice and was not measurable in SUR2AV/AV. A slight rightward shift of sensitivity to inhibition by glibenclamide was detected in SUR2AV/AV mice. Histopathological and qPCR analysis revealed atrophy of soleus and tibialis anterior muscles and up-regulation of atrogin-1 and MuRF1 mRNA in CS mice. (4) Conclusions: SUR2[A478V] “knock-in” mutation in mice impairs KATP channel modulation by MgATP, markedly so in SUR2AV/AV, with atrophy and non-inflammatory edema in different skeletal muscle phenotypes.

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Insight into Glutamatergic Involvement in Rewarding Effects of Mephedrone in Rats: In Vivo and Ex Vivo Study

Molecular Neurobiology ◽

10.1007/s12035-021-02404-y ◽

2021 ◽

Author(s):

Olga Wronikowska ◽

Maria Zykubek ◽

Agnieszka Michalak ◽

Anna Pankowska ◽

Paulina Kozioł ◽

...

Keyword(s):

Ex Vivo ◽

Interdisciplinary Approach ◽

Nmda Antagonist ◽

Exchange Chromatography ◽

Resonance Spectroscopy ◽

Monoamine Transporters ◽

Ex Vivo Study ◽

Insight Into

AbstractMephedrone is a widely used drug of abuse, exerting its effects by interacting with monoamine transporters. Although this mechanism has been widely studied heretofore, little is known about the involvement of glutamatergic transmission in mephedrone effects. In this study, we comprehensively evaluated glutamatergic involvement in rewarding effects of mephedrone using an interdisciplinary approach including (1) behavioural study on effects of memantine (non-selective NMDA antagonist) on expression of mephedrone-induced conditioned place preference (CPP) in rats; (2) evaluation of glutamate concentrations in the hippocampus of rats following 6 days of mephedrone administration, using in vivo magnetic resonance spectroscopy (MRS); and (3) determination of glutamate levels in the hippocampus of rats treated with mephedrone and subjected to MRS, using ion-exchange chromatography. In the presented research, we confirmed priorly reported mephedrone-induced rewarding effects in the CPP paradigm and showed that memantine (5 mg/kg) was able to reverse the expression of this effect. MRS study showed that subchronic mephedrone administration increased glutamate level in the hippocampus when measured in vivo 24 h (5 mg/kg, 10 mg/kg and 20 mg/kg) and 2 weeks (5 mg/kg and 20 mg/kg) after last injection. Ex vivo chromatographic analysis did not show significant changes in hippocampal glutamate concentrations; however, it showed similar results as obtained in the MRS study proving its validity. Taken together, the presented study provides new insight into glutamatergic involvement in rewarding properties of mephedrone.

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Characterization of Intrinsically Radiolabeled Poly(lactic-co-glycolic acid) Nanoparticles for ex Vivo Autologous Cell Labeling and in Vivo Tracking

Bioconjugate Chemistry ◽

10.1021/acs.bioconjchem.1c00271 ◽

2021 ◽

Author(s):

Massis Krekorian ◽

Gerwin G. W. Sandker ◽

Kimberley R. G. Cortenbach ◽

Oya Tagit ◽

N. Koen van Riessen ◽

...

Keyword(s):

Glycolic Acid ◽

Ex Vivo ◽

Cell Labeling ◽

Autologous Cell

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In vivo characterization of the transitional bronchioles by aerosol-derived airway morphometry

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.3.920 ◽

1999 ◽

Vol 87 (3) ◽

pp. 920-927 ◽

Cited By ~ 4

Author(s):

Kirby L. Zeman ◽

Gerhard Scheuch ◽

Knut Sommerer ◽

James S. Brown ◽

William D. Bennett

Keyword(s):

Ex Vivo ◽

Normal Subjects ◽

Characteristic Line ◽

Chronic Obstructive ◽

Obstructive Pulmonary Disease ◽

Lung Capacity ◽

Single Breath ◽

In Vivo Characterization

Effective airway dimensions (EADs) were determined in vivo by aerosol-derived airway morphometry as a function of volumetric lung depth (VLD) to identify and characterize, noninvasively, the caliber of the transitional bronchiole region of the human lung and to compare the EADs by age, gender, and disease. By logarithmically plotting EAD vs. VLD, two distinct regions of the lung emerged that were identified by characteristic line slopes. The intersection of proximal and distal segments was defined as VLDtransand associated EADtrans. In our normal subjects ( n = 20), VLDtrans [345 ± 83 (SD) ml] correlated significantly with anatomic dead space (224 ± 34 ml) and end of phase II of single-breath nitrogen washout (360 ± 53 ml). The corresponding EADtranswas 0.42 ± 0.07 mm, in agreement with other ex vivo measurements of the transitional bronchioles. VLDtrans was smaller (216 ± 64 ml) and EADtrans was larger (0.83 ± 0.04 mm) in our patients with chronic obstructive pulmonary disease ( n = 13). VLDtrans increased with age for children (age 8–18 yr; P = 0.006, n = 26) and with total lung capacity for age 8–81 yr ( P < 0.001, n = 61). This study extends the usefulness of aerosol-derived airway morphometry to in vivo measurements of the transitional bronchioles.

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Ex Vivo Isolation and Characterization of Cd4+Cd25+ T Cells with Regulatory Properties from Human Blood

Journal of Experimental Medicine ◽

10.1084/jem.193.11.1303 ◽

2001 ◽

Vol 193 (11) ◽

pp. 1303-1310 ◽

Cited By ~ 797

Author(s):

Detlef Dieckmann ◽

Heidi Plottner ◽

Susanne Berchtold ◽

Thomas Berger ◽

Gerold Schuler

Keyword(s):

T Cells ◽

Cytotoxic T Lymphocyte ◽

Ex Vivo ◽

Cell Receptor ◽

Regulatory Cells ◽

Suppressor T Cells ◽

Isolation And Characterization ◽

Regulatory Properties

It has been known for years that rodents harbor a unique population of CD4+CD25+ “professional” regulatory/suppressor T cells that is crucial for the prevention of spontaneous autoimmune diseases. Here we demonstrate that CD4+CD25+CD45RO+ T cells (mean 6% of CD4+ T cells) are present in the blood of adult healthy volunteers. In contrast to previous reports, these CD4+CD25+ T cells do not constitute conventional memory cells but rather regulatory cells exhibiting properties identical to their rodent counterparts. Cytotoxic T lymphocyte–associated antigen (CTLA)-4 (CD152), for example, which is essential for the in vivo suppressive activity of CD4+CD25+ T cells, was constitutively expressed, and remained strongly upregulated after stimulation. The cells were nonproliferative to stimulation via their T cell receptor for antigen, but the anergic state was partially reversed by interleukin (IL)-2 and IL-15. Upon stimulation with allogeneic (but not syngeneic) mature dendritic cells or platebound anti-CD3 plus anti-CD28 the CD4+CD25+ T cells released IL-10, and in coculture experiments suppressed the activation and proliferation of CD4+ and CD8+ T cells. Suppression proved IL-10 independent, yet contact dependent as in the mouse. The identification of regulatory CD4+CD25+ T cells has important implications for the study of tolerance in man, notably in the context of autoimmunity, transplantation, and cancer.

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