Influence of near-wall PIV data on recirculation hemodynamics in a patient-specific moderate stenosis: Experimental-numerical comparison

Biorheology ◽  
2020 ◽  
pp. 1-24
Author(s):  
Neha Sharma ◽  
Sudeep Sastry ◽  
John M. Sankovic ◽  
Jaikrishnan R. Kadambi ◽  
Rupak K. Banerjee
Keyword(s):  
Shear Rate ◽  
Linear Interpolation ◽  
Patient Specific ◽  
Numerical Comparison ◽  
Linear Quadratic ◽  
Quadratic Interpolation ◽  
Data Points ◽  
Recirculation Length ◽  
Near Wall

BACKGROUND: Recirculation zones within the blood vessels are known to influence the initiation and progression of atherosclerotic lesions. Quantification of recirculation parameters with accuracy remains subjective due to uncertainties in measurement of velocity and derived wall shear stress (WSS). OBJECTIVE: The primary aim is to determine recirculation height and length from PIV experiments while validating with two different numerical methods: finite-element (FE) and -volume (FV). Secondary aim is to analyze how FE and FV compare within themselves. METHODS: PIV measurements were performed to obtain velocity profiles at eight cross sections downstream of stenosis at flow rate of 200 ml/min. WSS was obtained by linear/quadratic interpolation of experimental velocity measurements close to wall. RESULTS: Recirculation length obtained from PIV technique was 1.47 cm and was within 2.2% of previously reported in-vitro measurements. Derived recirculation length from PIV agreed within 6.8% and 8.2% of the FE and FV calculations, respectively. For lower shear rate, linear interpolation with five data points results in least error. For higher shear rate either higher order (quadratic) interpolation with five data points or lower order (linear) with lesser (three) data points leads to better results. CONCLUSION: Accuracy of the recirculation parameters is dependent on number of near wall PIV data points and the type of interpolation algorithm used.

scholarly journals Application of Airy beam light sheet microscopy to examine early neurodevelopmental structures in 3D hiPSC-derived human cortical spheroids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Dwaipayan Adhya ◽  
George Chennell ◽  
James A. Crowe ◽  
Eva P. Valencia-Alarcón ◽  
James Seyforth ◽  
...  
Keyword(s):  
High Resolution ◽  
Human Brain ◽  
Light Sheet ◽  
Autism Spectrum ◽  
Model Systems ◽  
Large Field ◽  
Autism Spectrum Conditions ◽  
Patient Specific ◽  
Airy Beam

Abstract Background The inability to observe relevant biological processes in vivo significantly restricts human neurodevelopmental research. Advances in appropriate in vitro model systems, including patient-specific human brain organoids and human cortical spheroids (hCSs), offer a pragmatic solution to this issue. In particular, hCSs are an accessible method for generating homogenous organoids of dorsal telencephalic fate, which recapitulate key aspects of human corticogenesis, including the formation of neural rosettes—in vitro correlates of the neural tube. These neurogenic niches give rise to neural progenitors that subsequently differentiate into neurons. Studies differentiating induced pluripotent stem cells (hiPSCs) in 2D have linked atypical formation of neural rosettes with neurodevelopmental disorders such as autism spectrum conditions. Thus far, however, conventional methods of tissue preparation in this field limit the ability to image these structures in three-dimensions within intact hCS or other 3D preparations. To overcome this limitation, we have sought to optimise a methodological approach to process hCSs to maximise the utility of a novel Airy-beam light sheet microscope (ALSM) to acquire high resolution volumetric images of internal structures within hCS representative of early developmental time points. Results Conventional approaches to imaging hCS by confocal microscopy were limited in their ability to image effectively into intact spheroids. Conversely, volumetric acquisition by ALSM offered superior imaging through intact, non-clarified, in vitro tissues, in both speed and resolution when compared to conventional confocal imaging systems. Furthermore, optimised immunohistochemistry and optical clearing of hCSs afforded improved imaging at depth. This permitted visualization of the morphology of the inner lumen of neural rosettes. Conclusion We present an optimized methodology that takes advantage of an ALSM system that can rapidly image intact 3D brain organoids at high resolution while retaining a large field of view. This imaging modality can be applied to both non-cleared and cleared in vitro human brain spheroids derived from hiPSCs for precise examination of their internal 3D structures. This process represents a rapid, highly efficient method to examine and quantify in 3D the formation of key structures required for the coordination of neurodevelopmental processes in both health and disease states. We posit that this approach would facilitate investigation of human neurodevelopmental processes in vitro.

scholarly journals Pathophysiological In Vitro Profile of Neuronal Differentiated Cells Derived from Niemann-Pick Disease Type C2 Patient-Specific iPSCs Carrying the NPC2 Mutations c.58G>T/c.140G>T

2021 ◽  
Vol 22 (8) ◽  
pp. 4009
Author(s):  
Maik Liedtke ◽  
Christin Völkner ◽  
Alexandra V. Jürs ◽  
Franziska Peter ◽  
Michael Rabenstein ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Transmembrane Protein ◽  
Hereditary Disease ◽  
Cholesterol Homeostasis ◽  
Patient Specific ◽  
Differentiated Cells ◽  
Npc1 Gene ◽  
Niemann Pick

Niemann-Pick type C2 (NP-C2) disease is a rare hereditary disease caused by mutations in the NPC2 gene. NPC2 is a small, soluble protein consisting of 151 amino acids, primarily expressed in late endosomes and lysosomes (LE/LY). Together with NPC1, a transmembrane protein found in these organelles, NPC2 accomplishes the exclusion of cholesterol; thus, both proteins are essential to maintain cellular cholesterol homeostasis. Consequently, mutations in the NPC2 or NPC1 gene result in pathophysiological accumulation of cholesterol and sphingolipids in LE/LY. The vast majority of Niemann-Pick type C disease patients, 95%, suffer from a mutation of NPC1, and only 5% display a mutation of NPC2. The biochemical phenotype of NP-C1 and NP-C2 appears to be indistinguishable, and both diseases share several commonalities in the clinical manifestation. Studies of the pathological mechanisms underlying NP-C2 are mostly based on NP-C2 animal models and NP-C2 patient-derived fibroblasts. Recently, we established induced pluripotent stem cells (iPSCs), derived from a donor carrying the NPC2 mutations c.58G>T/c.140G>T. Here, we present a profile of pathophysiological in vitro features, shared by NP-C1 and NP-C2, of neural differentiated cells obtained from the patient specific iPSCs. Profiling comprised a determination of the NPC2 protein level, detection of cholesterol accumulation by filipin staining, analysis of oxidative stress, and determination of autophagy. As expected, the NPC2-deficient cells displayed a significantly reduced amount of NPC2 protein, and, accordingly, we observed a significantly increased amount of cholesterol. Most notably, NPC2-deficient cells displayed only a slight increase of reactive oxygen species (ROS), suggesting that they do not suffer from oxidative stress and express catalase at a high level. As a site note, comparable NPC1-deficient cells suffer from a lack of catalase and display an increased level of ROS. In summary, this cell line provides a valuable tool to gain deeper understanding, not only of the pathogenic mechanism of NP-C2, but also of NP-C1.

scholarly journals Depression patient-derived cortical neurons reveal potential biomarkers for antidepressant response

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yishai Avior ◽  
Shiri Ron ◽  
Dana Kroitorou ◽  
Claudia Albeldas ◽  
Vitaly Lerner ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Antidepressant Treatment ◽  
Patient Specific ◽  
Specific Gene ◽  
Specific Information ◽  
Patient Response ◽  
Patient Will ◽  
Gene Expression Alterations ◽  
Treatment Alternatives

AbstractMajor depressive disorder is highly prevalent worldwide and has been affecting an increasing number of people each year. Current first line antidepressants show merely 37% remission, and physicians are forced to use a trial-and-error approach when choosing a single antidepressant out of dozens of available medications. We sought to identify a method of testing that would provide patient-specific information on whether a patient will respond to a medication using in vitro modeling. Patient-derived lymphoblastoid cell lines from the Sequenced Treatment Alternatives to Relieve Depression study were used to rapidly generate cortical neurons and screen them for bupropion effects, for which the donor patients showed remission or non-remission. We provide evidence for biomarkers specific for bupropion response, including synaptic connectivity and morphology changes as well as specific gene expression alterations. These biomarkers support the concept of personalized antidepressant treatment based on in vitro platforms and could be utilized as predictors to patient response in the clinic.

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.

scholarly journals In Vitro Systematic Drug Testing Reveals Carboplatin, Paclitaxel, and Alpelisib as a Potential Novel Combination Treatment for Adult Granulosa Cell Tumors

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 368
Author(s):  
Joline Roze ◽  
Elena Sendino Garví ◽  
Ellen Stelloo ◽  
Christina Stangl ◽  
Ferdinando Sereno ◽  
...  
Keyword(s):  
Granulosa Cell ◽  
Cell Lines ◽  
Combination Treatment ◽  
Drug Testing ◽  
Drug Application ◽  
Hormonal Treatment ◽  
Patient Specific ◽  
Granulosa Cell Tumors ◽  
Potential Synergy

Adult granulosa cell tumors (AGCTs) arise from the estrogen-producing granulosa cells. Treatment of recurrence remains a clinical challenge, as systemic anti-hormonal treatment or chemotherapy is only effective in selected patients. We established a method to rapidly screen for drug responses in vitro using direct patient-derived cell lines in order to optimize treatment selection. The response to 11 monotherapies and 12 combination therapies, including chemotherapeutic, anti-hormonal, and targeted agents, were tested in 12 AGCT-patient-derived cell lines and an AGCT cell line (KGN). Drug screens were performed within 3 weeks after tissue collection by measurement of cell viability 72 h after drug application. The potential synergy of drug combinations was assessed. The human maximum drug plasma concentration (Cmax) and steady state (Css) thresholds obtained from available phase I/II clinical trials were used to predict potential toxicity in patients. Patient-derived AGCT cell lines demonstrated resistance to all monotherapies. All cell lines showed synergistic growth inhibition by combination treatment with carboplatin, paclitaxel, and alpelisib at a concentration needed to obtain 50% cell death (IC50) that are below the maximum achievable concentration in patients (IC50 < Cmax). We show that AGCT cell lines can be rapidly established and used for patient-specific in vitro drug testing, which may guide treatment decisions. Combination treatment with carboplatin, paclitaxel, and alpelisib was consistently effective in AGCT cell lines and should be further studied as a potential effective combination for AGCT treatment in patients.

scholarly journals In vitro evaluation of cerebrospinal fluid velocity measurement in type I Chiari malformation: repeatability, reproducibility, and agreement using 2D phase contrast and 4D flow MRI

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Gwendolyn Williams ◽  
Suraj Thyagaraj ◽  
Audrey Fu ◽  
John Oshinski ◽  
Daniel Giese ◽  
...  
Keyword(s):  
Chiari Malformation ◽  
Phase Contrast ◽  
Patient Specific ◽  
Type I ◽  
4D Flow ◽  
Csf Dynamics ◽  
Flow Measurements ◽  
Repeatability And Reproducibility ◽  
Flow Techniques

Abstract Background Phase contrast magnetic resonance imaging, PC MRI, is a valuable tool allowing for non-invasive quantification of CSF dynamics, but has lacked adoption in clinical practice for Chiari malformation diagnostics. To improve these diagnostic practices, a better understanding of PC MRI based measurement agreement, repeatability, and reproducibility of CSF dynamics is needed. Methods An anatomically realistic in vitro subject specific model of a Chiari malformation patient was scanned three times at five different scanning centers using 2D PC MRI and 4D Flow techniques to quantify intra-scanner repeatability, inter-scanner reproducibility, and agreement between imaging modalities. Peak systolic CSF velocities were measured at nine axial planes using 2D PC MRI, which were then compared to 4D Flow peak systolic velocity measurements extracted at those exact axial positions along the model. Results Comparison of measurement results showed good overall agreement of CSF velocity detection between 2D PC MRI and 4D Flow (p = 0.86), fair intra-scanner repeatability (confidence intervals ± 1.5 cm/s), and poor inter-scanner reproducibility. On average, 4D Flow measurements had a larger variability than 2D PC MRI measurements (standard deviations 1.83 and 1.04 cm/s, respectively). Conclusion Agreement, repeatability, and reproducibility of 2D PC MRI and 4D Flow detection of peak CSF velocities was quantified using a patient-specific in vitro model of Chiari malformation. In combination, the greatest factor leading to measurement inconsistency was determined to be a lack of reproducibility between different MRI centers. Overall, these findings may help lead to better understanding for application of 2D PC MRI and 4D Flow techniques as diagnostic tools for CSF dynamics quantification in Chiari malformation and related diseases.

scholarly journals The Promise of Human Induced Pluripotent Stem Cells in Dental Research

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Thekkeparambil Chandrabose Srijaya ◽  
Padmaja Jayaprasad Pradeep ◽  
Rosnah Binti Zain ◽  
Sabri Musa ◽  
Noor Hayaty Abu Kasim ◽  
...  
Keyword(s):  
Stem Cells ◽  
Induced Pluripotent Stem Cells ◽  
Pluripotent Stem Cells ◽  
Disease Modeling ◽  
Patient Specific ◽  
Dental Research ◽  
Cell Based Therapy ◽  
Induced Pluripotent ◽  
Disease Specific

Induced pluripotent stem cell-based therapy for treating genetic disorders has become an interesting field of research in recent years. However, there is a paucity of information regarding the applicability of induced pluripotent stem cells in dental research. Recent advances in the use of induced pluripotent stem cells have the potential for developing disease-specific iPSC linesin vitrofrom patients. Indeed, this has provided a perfect cell source for disease modeling and a better understanding of genetic aberrations, pathogenicity, and drug screening. In this paper, we will summarize the recent progress of the disease-specific iPSC development for various human diseases and try to evaluate the possibility of application of iPS technology in dentistry, including its capacity for reprogramming some genetic orodental diseases. In addition to the easy availability and suitability of dental stem cells, the approach of generating patient-specific pluripotent stem cells will undoubtedly benefit patients suffering from orodental disorders.

Functional precision medicine in colorectal cancer based on patient-derived tumoroids and in-vitro sensitivity drug testing.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15567-e15567
Author(s):  
Lars Henrik Jensen ◽  
Anders Kristian Moeller Jakobsen ◽  
Birgitte Mayland Havelund ◽  
Cecilie Abildgaard ◽  
Chris Vagn-Hansen ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Clinical Trial ◽  
Primary Endpoint ◽  
Drug Testing ◽  
Progression Free Survival ◽  
Patient Specific ◽  
Precision Oncology ◽  
Sensitivity Testing ◽  
In Vitro Sensitivity

e15567 Background: Precision oncology based on in-vitro, functional assays has potential advantages compared to the much more common molecular approach, but the clinical benefit is unknown. We here report the results from the largest prospective interventional clinical trial testing the clinical outcome in colorectal cancer patients treated with drugs showing cytotoxic effect in matched patient-derived tumoroids. Methods: This single-center, phase II trial included patients with metastatic colorectal cancer previously exposed to all standard therapies. Specimens from one to three 18-16 G core needle biopsies were manually dissected, enzymatically treated, cultivated, and incubated to form 3D spherical microtumors, i.e. tumoroids. In the assay for in-vitro sensitivity testing, the tumoroids were challenged with single drugs and combinations thereof to determine patient-specific responses. Using tumoroid screening technology (IndiTreat, 2cureX, Copenhagen, Denmark), results were generated by comparing the sensitivity of the individual patient’s tumoroids with a reference panel from other patients. The testing included standard cytostatics and drugs with proven effect in previous early-phase clinical trials, a total of 15 drugs. The primary endpoint was the fraction of patients with progression-free survival (PFS) at two months. Based on placebo arms in randomized last-line trials, a minimal relevant difference of 20% (20% to 40%) was stated. Using Simon's two-stage design, a sample size of 45 patients was calculated with at least 14 PFS at two months (significance 5%, power 90%). Results: Ninety patients were enrolled from 9/2017 to 9/2020. Biopsies from 82 patients were obtained and sent for tumoroid formation of which 44 (54%, 95% CI 42-65) were successful and at least one treatment was suggested. Thirty-four patients initiated treatment according to the response obtained in the drug assays within a median of 51 days from inclusion (IQR 39-63). The primary endpoint, PFS at two months, was met in 17 of 34 patients (50%, 95%CI 32-68). There were no radiological responses. Median PFS was 81 days (95% CI 51-112) and median OS was 189 days (95% CI 103-277). Conclusions: Precision oncology using a functional approach with patient-derived tumoroids and in-vitro drug sensitivity testing seems feasible. The approach is limited by the fraction of patients with successful tumoroid development. The primary endpoint was met, as half of the patients were without progression at two months. Further clinical studies are justified. Clinical trial information: NCT03251612.

Abstract 518: In Vitro and in vivo Disease Modeling Using Patient Derived iPSCs to Characterize the Calcification Phenotype in Arterial Calcification Due to Deficiency of CD73

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Cynthia St. Hilaire ◽  
Hui Jin ◽  
Yuting Huang ◽  
Dan Yang ◽  
Alejandra Negro ◽  
...  
Keyword(s):  
Vascular Calcification ◽  
Disease Modeling ◽  
Induced Pluripotent Stem Cell ◽  
Dermal Fibroblasts ◽  
In Vivo Studies ◽  
Arterial Calcification ◽  
Patient Specific ◽  
And Control

Objective: The objective of this study was to develop a patient-specific induced pluripotent stem cell (iPSC)-based disease model to understand the process by which CD73-deficiency leads to vascular calcification in the disease, Arterial Calcification due to Deficiency of CD73 (ACDC). Approach & Results: ACDC is an autosomal recessive disease resulting from mutations in the gene encoding for CD73, which converts extracellular AMP to adenosine. CD73-deficiency manifests with tortuosity and vascular calcification of the medial layer of lower-extremity arteries, a pathology associated with diabetes and chronic kidney disease. We previously identified that dermal fibroblasts isolated from ACDC patients calcify in vitro, however in vivo studies of the vasculature are limited, as murine models of CD73 deficiency do not recapitulate the human disease phenotype. Thus, we created iPSCs from ACDC patients and control fibroblasts. ACDC and Control iPSCs form teratomas when injected in immune-compromised mice, however ACDC iPSC teratomas exhibit extensive calcifications. Control and ACDC iPSCs were differentiated down the mesenchymal lineage (MSC) and while there was no difference in chondrogenesis and adipogenesis, ACDC iMSCs underwent osteogenesis sooner than control iPSC, have higher activity of tissue-nonspecific alkaline phosphatase (TNAP), and lower levels of extracellular adenosine. During osteogenic simulation, TNAP activity in ACDC cells significantly increased adenosine levels, however, not to levels needed for functional compensatory stimulation of the adenosine receptors. Inhibition of TNAP with levimisole ablates this increase in adenosine. Treatment with an A2b adenosine receptor (AR) agonist drastically reduced TNAP activity in vitro, and calcification in ACDC teratomas, as did treatment with etidronate, which is currently being tested in a clinical trial on ACDC patients. Conclusions: These results illustrate a pro-osteogenic phenotype in CD73-deficient cells whereby TNAP activity attempts to compensate for CD73 deficiency, but subsequently induces calcification that can be reversed by activation of the A2bAR. The iPSC teratoma model may be used to screen other potential therapeutics for calcification disorders.

scholarly journals Designer blood: creating hematopoietic lineages from embryonic stem cells

Blood ◽  
2006 ◽  
Vol 107 (4) ◽  
pp. 1265-1275 ◽  
Author(s):  
Abby L. Olsen ◽  
David L. Stachura ◽  
Mitchell J. Weiss
Keyword(s):  
Stem Cells ◽  
Es Cells ◽  
Embryonic Stem ◽  
Basic Research ◽  
Cell Types ◽  
Patient Specific ◽  
Es Cell ◽  
Blood Disorders ◽  
Hematopoietic Stem

Embryonic stem (ES) cells exhibit the remarkable capacity to become virtually any differentiated tissue upon appropriate manipulation in culture, a property that has been beneficial for studies of hematopoiesis. Until recently, the majority of this work used murine ES cells for basic research to elucidate fundamental properties of blood-cell development and establish methods to derive specific mature lineages. Now, the advent of human ES cells sets the stage for more applied pursuits to generate transplantable cells for treating blood disorders. Current efforts are directed toward adapting in vitro hematopoietic differentiation methods developed for murine ES cells to human lines, identifying the key interspecies differences in biologic properties of ES cells, and generating ES cell-derived hematopoietic stem cells that are competent to repopulate adult hosts. The ultimate medical goal is to create patient-specific and generic ES cell lines that can be expanded in vitro, genetically altered, and differentiated into cell types that can be used to treat hematopoietic diseases.

Sign in / Sign up

Export Citation Format

Share Document