The influence of downstream arterial perfusion parameters on Doppler pulsatility index and resistance index in an in-vitro perfusion model

VASA ◽  
2006 ◽  
Vol 35 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Schmidt ◽  
Ockert ◽  
Deußen ◽  
Schellong
Keyword(s):  
Reflection Coefficient ◽  
Pulsatility Index ◽  
In Vitro Model ◽  
Peripheral Resistance ◽  
Resistance Index ◽  
In Vitro Perfusion ◽  
Arterial Perfusion ◽  
Vitro Model ◽  
The Relationship

Background: To investigate in vitro how downstream perfusion parameters influence pulsatility index (PI), resistance index (RI) and their constituting Doppler velocities. Materials and methods: We analyzed the influence of resistance, compliance, reflection coefficient and input impedance on PI and RI in an in-vitro model of arterial flow. Results: The nominators of PI and RI were determined by resistance. The numerators were determined by compliance and by the reflection coefficient. There were close relationships of PI and RI with resistance under the condition of constant compliance, but not when compliance was variable. Conclusion: PI and RI consist of velocity terms which are independently influenced by different parameters of impedance: compliance, reflection coefficient and resistance. These findings explain the contradictory results reported for the relationship between the indices and peripheral resistance in studies where compliance and reflection effects were not considered.

scholarly journals Human Brain Organoids as an In Vitro Model System of Viral Infectious Diseases

2022 ◽  
Vol 12 ◽  
Author(s):  
Xuan Su ◽  
Peng Yue ◽  
Jing Kong ◽  
Xin Xu ◽  
Yu Zhang ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Viral Infections ◽  
Cns Infection ◽  
Great Promise ◽  
Zikv Infection ◽  
Infection Models ◽  
Immunodeficiency Virus ◽  
Vitro Model ◽  
The Relationship

Brain organoids, or brainoids, have shown great promise in the study of central nervous system (CNS) infection. Modeling Zika virus (ZIKV) infection in brain organoids may help elucidate the relationship between ZIKV infection and microcephaly. Brain organoids have been used to study the pathogenesis of SARS-CoV-2, human immunodeficiency virus (HIV), HSV-1, and other viral infections of the CNS. In this review, we summarize the advances in the development of viral infection models in brain organoids and their potential application for exploring mechanisms of viral infections of the CNS and in new drug development. The existing limitations are further discussed and the prospects for the development and application of brain organs are prospected.

Thrombus Characterization with Intravascular Ultrasound: Potential to Predict Successful Thrombolysis

2003 ◽  
Vol 10 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Damon Kwan ◽  
Andrew Dries ◽  
Tamara Burton ◽  
Guru Bhandari ◽  
Daniel Young ◽  
...  
Keyword(s):  
Intravascular Ultrasound ◽  
In Vitro Model ◽  
Reference Standard ◽  
Arterial Perfusion ◽  
Perfusion Model ◽  
Rf Signals ◽  
Vitro Model ◽  
Attenuation Characteristics ◽  
Successful Thrombolysis

Purpose: To define analysis methods using radiofrequency (RF) data from intravascular ultrasound (IVUS) to characterize thrombus so that the success or failure of thrombolysis can be predicted. Methods: Experimentation was done in 2 phases: first, 40 clots created from platelet-rich (n = 20) and platelet-poor (n = 20) plasma were imaged with 20 and 30-MHz IVUS probes. The digitized RF signals were analyzed to determine the attenuation and slope of attenuation characteristics as a reference standard for the second part of the study. In this phase, 20 perfusion trials were performed with 10 platelet-rich and 10 platelet-poor samples in an in vitro arterial perfusion model; the composition of the samples was blinded during interrogation with IVUS. Alteplase (0.1 mg) was then infused directly into the thrombus for 1 hour; restoration of flow and amount of lysis were quantified. Results: Significant differences were detected for the integrated attenuation value (p<0.001) between platelet-poor and platelet-rich clots interrogated with a 30-MHz probe, but no differences were noted using the 20-MHz catheter. However, both transducers were capable of differentiating platelet-rich and platelet-poor clots using a slope of attenuation analysis, which was successful in identifying all 20 (100%) of the blinded clots in the in vitro model. The speed and completeness of lysis were significantly higher (p<0.05) for platelet-rich (78%) than platelet-poor (21%) clots. Conclusions: IVUS preprocessed imaging is capable of differentiating various types of thrombus. This information can be used to predict the success or failure of pharmacological lysis techniques.

A Human 3D In Vitro Model to Assess the Relationship Between Osteoporosis and Dissemination to Bone of Breast Cancer Tumor Cells

2017 ◽  
Vol 232 (7) ◽  
pp. 1826-1834 ◽  
Author(s):  
Francesca Salamanna ◽  
Veronica Borsari ◽  
Silvia Brogini ◽  
Paola Torricelli ◽  
Simona Cepollaro ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
In Vitro Model ◽  
3D In Vitro Model ◽  
Cancer Tumor ◽  
Vitro Model ◽  
The Relationship

A New in vitro Model to Study the Relationship of Gap Size and Secondary Caries

2007 ◽  
Vol 41 (6) ◽  
pp. 467-473 ◽  
Author(s):  
P. Totiam ◽  
C. González-Cabezas ◽  
M.R. Fontana ◽  
D.T. Zero
Keyword(s):  
In Vitro Model ◽  
Gap Size ◽  
Secondary Caries ◽  
Vitro Model ◽  
Relationship Of ◽  
The Relationship

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

Sign in / Sign up

Export Citation Format

Share Document