Effects of Transport Medium Composition on in vitro Drug Permeation across Excised Pig Intestinal Tissue

2020 ◽  
Vol 10 ◽  
Author(s):  
Bianca Peterson ◽  
Henrico Heystek ◽  
Josias H. Hamman ◽  
Johan D. Steyn
Keyword(s):  
Medium Composition ◽  
Screening Tests ◽  
Intestinal Tissue ◽  
Predictive Values ◽  
Transport Medium ◽  
Intestinal Fluids ◽  
Lower Permeability ◽  
The Impact ◽  
Simulated Intestinal Fluids

Background:: Knowledge of the permeation characteristics of new chemical entities across biological membranes is essential to drug research and development. Transport medium composition may affect the absorption of compounds during in vitro drug transport testing. To preserve the predictive values of screening tests, the possible influence of transport media on the solubility of model drugs, and on the activities of tight junctions and efflux transporter proteins (e.g. P-glycoprotein) must be known. Objective:: The aim of this study was to compare the impact of different transport media on the bi-directional transport of standard compounds, selected from the four classes of the Biopharmaceutical Classification System (BCS), across excised pig intestinal tissue. Methods:: The Sweetana-Grass diffusion apparatus was used for the transport studies. Krebs-Ringer bicarbonate (KRB) buffer and simulated intestinal fluids in the fed (FeSSIF) and fasted (FaSSIF) states were used as the three transport media, while the chosen compounds were abacavir (BCS class 1), dapsone (BCS class 2), lamivudine (BCS class 3) and furosemide (BCS class 4). Results:: Abacavir exhibited lower permeability in both the simulated intestinal fluids than in the KRB buffer. Dapsone showed similar permeability in all media. Lamivudine exhibited lower permeability in FaSSIF than in the other two media. Furosemide exhibited improved transport with pronounced efflux in FaSSIF. Conclusion:: Different permeation behaviors were observed for the selected drugs in the respective media, which may have resulted from their different physico-chemical properties, as well as from the effects that dissimilar transport media components had on excised pig intestinal tissue.

Soaps and Detergents: Alternatives to Animal Eye Irritation Tests

1996 ◽  
Vol 15 (1) ◽  
pp. 1-44 ◽  
Author(s):  
Mildred S. Christian ◽  
Robert M. Diener
Keyword(s):  
False Negative ◽  
Screening Tools ◽  
Current Status ◽  
In Vitro Assays ◽  
Computer Search ◽  
Eye Irritation ◽  
Vitro Assay ◽  
Predictive Values ◽  
The Impact

An extensive computer search was conducted, and a comprehensive overview of the current status of alternatives to animal eye irritation tests was obtained. A search of Medline and Toxline databases (1988 to present) was supplemented with references from sources regarding in vitro eye irritation. Particular attention was paid to soap and detergent products and related ingredients. Eighty-five references are included in the review; the in vitro assays are categorized, and their predictive values for assessing acute ocular irritation are evaluated and compared with the Draize rabbit eye irritation assay and with each other. The present review shows that the increased activity of scientists from academia, industry, and regulatory agencies has resulted in substantial progress in developing alternative in vitro procedures and that a number of large, interlaboratory evaluations and international workshops have assisted in the selection process. However, none of these methodologies has obtained acceptance for regulatory classification purposes. Conclusions drawn from this review include that (a) no single in vitro assay is considered capable of replacing the Draize eye irritation test; (b) the chorioallantoic membrane vascular assay (CAMVA) or the hen egg test-chorio-allantoic membrane test (HET-CAM), the chicken or bovine enucleated eye test, the neutral red and plasminogen activation assays for cytotoxicity, and the silicon microphysiometer appear to have the greatest potential as screening tools for eye irritation; and (c) choosing a specific assay or series of assays will depend on the type of agent tested and the impact of false-negative or false-positive results. New assays will continue to be developed and should be included in future evaluations, when sufficient data are available.

THE IMPACT OF NUTRIENT MEDIUM COMPOSITION ON PROPAGATION OF PHLOX SIBIRICA L. IN IN VITRO CULTURE

2019 ◽  
Vol 0 (2) ◽  
pp. 66-72
Author(s):  
A.Sh. Akhmetova ◽  
◽  
A.A. Zaripova ◽  
A.I. Shigapova ◽  
◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Nutrient Medium ◽  
Medium Composition ◽  
The Impact

The impact of medium composition and photosynthetically active radiation level on the initial in vitro growth and production of flavonoids of Vernonia condensata Baker

2019 ◽  
Vol 18 ◽  
pp. 101063 ◽  
Author(s):  
Fabíola Rebouças Rodrigues ◽  
Dayse Alessandra Almeida Silva Bispo ◽  
Hugo Neves Brandão ◽  
Taliane Leila Soares ◽  
Weliton Antonio Bastos de Almeida ◽  
...  
Keyword(s):  
Photosynthetically Active Radiation ◽  
Medium Composition ◽  
In Vitro Growth ◽  
Radiation Level ◽  
Active Radiation ◽  
The Impact

scholarly journals Human Bone Marrow Mesenchymal Stem/Stromal Cells Preserve Their Immunomodulatory and Chemotactic Properties When Expanded in a Human Plasma Derived Xeno-Free Medium

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
A. Blázquez-Prunera ◽  
C. R. Almeida ◽  
M. A. Barbosa
Keyword(s):  
Bone Marrow ◽  
Human Plasma ◽  
Medium Composition ◽  
In Vitro Assays ◽  
Migration And Invasion ◽  
Potential Candidate ◽  
Free Medium ◽  
Cell Therapies ◽  
The Impact

Due to their immunomodulatory and chemotactic properties, hMSC are being explored to treat immune-related diseases. For their use in human therapies, it is necessary to culture hMSC in xeno-free conditions. In this study, the impact that a xeno-free medium based on a human plasma derivate has on these properties was analysed. Bone marrow-derived hMSC preserved their immunosuppressive and immunostimulatory properties, as observed with in vitro assays with hMSC cocultured with mixed leukocyte reactions or with mitogen-stimulated leukocytes. Moreover, hMSC expanded in xeno-free medium were recruited by macrophages in both migration and invasion assays, which indicates that the cells maintained their chemotactic properties. These data suggest that xeno-free expanded hMSC preserved their immunomodulatory and chemotactic properties, indicating that the described xeno-free medium composition is a potential candidate to culture and expand hMSC for human cell therapies.

scholarly journals IMCA Induces Ferroptosis Mediated by SLC7A11 through the AMPK/mTOR Pathway in Colorectal Cancer

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Lei Zhang ◽  
Wen Liu ◽  
Fangyan Liu ◽  
Qun Wang ◽  
Mengjiao Song ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Screening Tests ◽  
Therapeutic Drug ◽  
Solute Carrier Family ◽  
Colorectal Cancer Cells ◽  
Solute Carrier ◽  
The Impact

Ferroptosis, implicated in several diseases, is a new form of programmed and nonapoptotic cell death triggered by iron-dependent lipid peroxidation after inactivation of the cystine/glutamate antiporter system xc–, which is composed of solute carrier family 7 membrane 11 (SLC7A11) and solute carrier family 3 membrane 2 (SLC3A2). Therefore, inducing ferroptosis through inhibiting the cystine/glutamate antiporter system xc– may be an effective way to treat cancer. In previous screening tests, we found that the benzopyran derivative 2-imino-6-methoxy-2H-chromene-3-carbothioamide (IMCA) significantly inhibited the viability of colorectal cancer cells. However, the impact of IMCA on ferroptosis remains unknown. Hence, this study investigated the effect of IMCA on ferroptosis and elucidated the underlying molecular mechanism. Results showed that IMCA significantly inhibited the cell viability of colorectal cancer cells in vitro and inhibited tumor growth with negligible organ toxicity in vivo. Further studies showed that IMCA significantly induced the ferroptosis of colorectal cancer cells. Mechanistically, IMCA downregulated the expression of SLC7A11 and decreased the contents of cysteine and glutathione, which resulted in reactive oxygen species accumulation and ferroptosis. Furthermore, overexpression of SLC7A11 significantly attenuated the ferroptosis caused by IMCA. In addition, IMCA regulated the activity of the AMPK/mTOR/p70S6k signaling pathway, which is related to the activity of SLC7A11 and ferroptosis. Collectively, our research provided experimental evidences on the activity and mechanism of ferroptosis induced by IMCA and revealed that IMCA might be a promising therapeutic drug for colorectal cancer.

Relationship between the characteristics of frozen-thawed ram spermatozoa and in vitro embryo production

2001 ◽  
Vol 13 (3) ◽  
pp. 193 ◽  
Author(s):  
Lee H. A. Morris ◽  
W. H. Johnson ◽  
S. P. Leibo ◽  
B. C. Buckrell
Keyword(s):  
Logistic Regression ◽  
Sperm Motility ◽  
Membrane Integrity ◽  
Screening Tests ◽  
Breeding Programme ◽  
Embryo Production ◽  
Predictive Values ◽  
Commercial Breeding ◽  
In Vitro Embryo Production

To select rams suitable for ovine in vitro embryo production (IVP), the predictive values of the screening tests used to identify unsuitable rams need to be established. The present study examined some characteristics of frozen–thawed ram spermatozoa that might be evaluated routinely in a commercial breeding programme. These included sperm motility, plasma membrane integrity, morphology, and acrosome and capacitation status of the sperm population. Cryopreserved spermatozoa from four Dorset rams, which had previously satisfied the selection criteria for inclusion in a commercial breeding programme, were used for IVP. The overall contribution of the four rams and the ejaculates within each ram to the variability (R2) in the production of blastocysts was very small (2.1% and 2.5% respectively). The analysis of the sperm characteristics by logistic regression revealed a significant and positive association between total post-thaw sperm motility, viability and longevity with in vitro blastocyst production. However, there was no association between the other surface characteristics of the spermatozoa measured in this study with embryo production. Despite the absence of differences between the rams in the low incidence of polyspermic fertilization, the significant and detrimental effects of polyspermic fertilization on in vitro blastocyst production rates were quantified by logistic regression analysis. A large proportion of the variability within the IVP system was unaccounted for by the analysis of sperm and oocyte characteristics evaluated in this study. Thus, the identification of other factors contributing to the variability in the production of embryos in vitro warrants further investigation. No single sperm characteristic was sufficient to predict the ultimate outcome of blastocyst production. Rather, assessments of multiple characteristics within the IVP system are required to make accurate predictions.

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