Quantitative evaluation of fibrinolytic enzymes in a simulated human system

1964 ◽  
Vol 19 (3) ◽  
pp. 536-539 ◽  
Author(s):  
Albert E. Munson ◽  
Nathan Back ◽  
Clara M. Ambrus ◽  
Howard Lassman ◽  
Eugene Lippschutz ◽  
...  

A simple in vitro system for the assay of fibrinolytic enzymes intended for therapeutic use has been described. The system employs small quantities of human plasma from outdated bank blood as perfusing medium and purified human fibrin clots labeled with radioactive iodine. Thus, it is possible to follow the dissolution of a human clot without the intervention of reactions of the vascular system (e.g., release of activators). It was shown that the simulated system compares favorably with the in vivo assay. In the assay of a urokinase-activated human plasmin preparation, substitution of human plasma with dog plasma as a perfusing medium resulted in a decrease of the fibrinolytic response. In the case of two preparations, data from the simulated human system correlated well with results of preliminary clinical testing. In using this system as an initial screen for fibrinolytic agents, one must be aware of the fact that in vitro systems represent only part of the mechanisms involved in physiologic or pathologic processes. fibrinolysin system; plasmin; urokinase; thrombolysis; plasma Submitted on December 6, 1963

1980 ◽  
Vol 69 (11) ◽  
pp. 1282-1284 ◽  
Author(s):  
M.I. Genua ◽  
J. Giraldez ◽  
E. Rocha ◽  
A. Monge

Author(s):  
Ren Tanimoto ◽  
Kyota Yoshida ◽  
Shinya Ikeda ◽  
Yayoi Obata

AbstractIn vitro systems capable of reconstituting the process of mouse oogenesis are now being established to help develop further understanding of the mechanisms underlying oocyte/follicle development and differentiation. These systems could also help increase the production of useful livestock or genetically modified animals, and aid in identifying the causes of infertility in humans. Recently, we revealed, using an in vitro system for recapitulating oogenesis, that the activation of the estrogen signaling pathway induces abnormal follicle formation, that blocking estrogen-induced expression of anti-Müllerian hormone is crucial for normal follicle formation, and that the production of α-fetoprotein in fetal liver tissue is involved in normal in vivo follicle formation. In mouse fetuses, follicle formation is not carried out by factors within the ovaries but is instead orchestrated by distal endocrine factors. This review outlines findings from genetics, endocrinology, and in vitro studies regarding the factors that can affect the formation of primordial follicles in mammals.


Blood ◽  
2003 ◽  
Vol 102 (9) ◽  
pp. 3120-3128 ◽  
Author(s):  
Kim Klarmann ◽  
Mariaestela Ortiz ◽  
Meghan Davies ◽  
Jonathan R. Keller

AbstractOur laboratory recently identified a quiescent class of pluripotent hematopoietic stem cells (PHSCs) that are lineage negative (Linneg), lack c-Kit, and are able to give rise to c-Kit–positive (c-Kitpos) PHSCs in vivo. This population fails to proliferate in vitro but has delayed reconstituting activity in vivo. In this study, we purified these cells to enrich for the PHSCs and we identified in vitro conditions capable of supporting their maturation. The c-Kit–negative (c-Kitneg) cells exhibited differential expression of Sca-1, CD34, CD43, CD45, and Thy 1.2. We purified the cells based on Sca-1, as it is expressed on active PHSCs. We detected pre–colony-forming unit spleen (pre–CFU-s) activity in both the Sca-1neg and Sca-1pos populations, indicating the presence of primitive PHSCs in both populations. However, our in vitro studies suggest that the Sca-1pos population is enriched for PHSCs. The in vitro systems that support the growth of these dormant cells include a modified long-term marrow culture and various stromal cell lines. In modified long-term bone marrow cultures, c-Kitneg cells gave rise to c-Kitpos PHSCs, with long-term reconstitution activity in vivo. Thus we have established an in vitro system to examine PHSC maturation that will allow us to study the mediators of the c-Kitneg to c-Kitpos transition.


1975 ◽  
Vol 33 (03) ◽  
pp. 617-631 ◽  
Author(s):  
H. S Kingdon ◽  
R. L Lundblad ◽  
J. J Veltkamp ◽  
D. L Aronson

SummaryFactor IX concentrates manufactured from human plasma and intended for therapeutic infusion in man have been suspected for some time of being potentially thrombogenic. In the current studies, assays were carried out in vitro and in vivo for potentially thrombogenic materials. It was possible to rank the various materials tested according to the amount of thrombogenic material detected. For concentrates not containing heparin, there was substantial agreement between the in vivo and in vitro assays, with a coefficient of correlation of 0.77. There was no correlation between the assays for thrombogenicity and the antithrombin III content. We conclude that many presently available concentrates of Factor IX contain substantial amounts of potentially thrombogenic enzymes, and that this fact must be considered in arriving at the decision whether or not to use them therapeutically.


1992 ◽  
Vol 67 (01) ◽  
pp. 060-062 ◽  
Author(s):  
J Harsfalvi ◽  
E Tarcsa ◽  
M Udvardy ◽  
G Zajka ◽  
T Szarvas ◽  
...  

Summaryɛ(γ-glutamyl)lysine isodipeptide has been detected in normal human plasma by a sensitive HPLC technique in a concentration of 1.9-3.6 μmol/1. Incubation of in vitro clotted plasma at 37° C for 12 h resulted in an increased amount of isodipeptide, and there was no further significant change when streptokinase was also present. Increased in vivo isodipeptide concentrations were also observed in hypercoagulable states and during fibrinolytic therapy.


2021 ◽  
Vol 22 (15) ◽  
pp. 7929
Author(s):  
Megan Chesnut ◽  
Thomas Hartung ◽  
Helena Hogberg ◽  
David Pamies

Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.


The Analyst ◽  
2021 ◽  
Author(s):  
Subhajit Chakraborty ◽  
Atanu Nandy ◽  
Subhadip Ghosh ◽  
Nirmal Kumar Das ◽  
Sameena Parveen ◽  
...  

Sub-nanomolar selective detection of Hg(ii) ions by protein (Human Serum Albumin, HSA) templated gold nanoclusters (AuNCs), both in in vitro as well as in vivo environments and specific endocytose behaviour towards breast cancer (BC) cell lines.


2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Nahed El-Najjar ◽  
Rashmi P. Kulkarni ◽  
Nancy Nader ◽  
Rawad Hodeify ◽  
Khaled Machaca

Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+signaling, including most prominently an inhibition of the passive ER Ca2+leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+signaling machinery are different.


2007 ◽  
Vol 6 (12) ◽  
pp. 2214-2221 ◽  
Author(s):  
Lois M. Douglas ◽  
Li Li ◽  
Yang Yang ◽  
A. M. Dranginis

ABSTRACT The Flo11/Muc1 flocculin has diverse phenotypic effects. Saccharomyces cerevisiae cells of strain background Σ1278b require Flo11p to form pseudohyphae, invade agar, adhere to plastic, and develop biofilms, but they do not flocculate. We show that S. cerevisiae var. diastaticus strains, on the other hand, exhibit Flo11-dependent flocculation and biofilm formation but do not invade agar or form pseudohyphae. In order to study the nature of the Flo11p proteins produced by these two types of strains, we examined secreted Flo11p, encoded by a plasmid-borne gene, in which the glycosylphosphatidylinositol anchor sequences had been replaced by a histidine tag. A protein of approximately 196 kDa was secreted from both strains, which upon purification and concentration, aggregated into a form with a very high molecular mass. When secreted Flo11p was covalently attached to microscopic beads, it conferred the ability to specifically bind to S. cerevisiae var. diastaticus cells, which flocculate, but not to Σ1278b cells, which do not flocculate. This was true for the 196-kDa form as well as the high-molecular-weight form of Flo11p, regardless of the strain source. The coated beads bound to S. cerevisiae var. diastaticus cells expressing FLO11 and failed to bind to cells with a deletion of FLO11, demonstrating a homotypic adhesive mechanism. Flo11p was shown to be a mannoprotein. Bead-to-cell adhesion was inhibited by mannose, which also inhibits Flo11-dependent flocculation in vivo, further suggesting that this in vitro system is a useful model for the study of fungal adhesion.


2007 ◽  
Vol 57 (4) ◽  
pp. 441-450 ◽  
Author(s):  
Savita Vyas ◽  
Piyush Trivedi ◽  
Subhash Chaturvedi

Ketorolac-dextran conjugates: Synthesis,in vitroandin vivoevaluationKetorolac is a non-steroidal anti-inflammatory drug. Dextran conjugates of ketorolac (KD) were synthesized and characterized to improve ketorolac aqueous solubility and reduce gastrointestinal side effects. An N-acylimidazole derivative of ketorolac (KAI) was condensed with a model carrier polymer, dextran of different molecular masses (40000, 60000, 110000 and 200000). IR spectral data confirmed formation of ester bonding. Ketorolac contents were evaluated by UV-spectrophotometric analysis. The molecular mass was determined by measuring viscosity using the Mark-Howink-Sakurada equation. Invitrohydrolysis studies were performed in aqueous buffers (pH 1.2, 7.4, 9) and in 80% (V/V) human plasma (pH 7.4). At pH 9, a higher rate of ketorolac release from KD was observed as compared to aqueous buffer of pH 7.4 and 80% human plasma (pH 7.4), following first-order kinetics.In vivobiological screening in mice and rats indicated that conjugates retained analgesic and anti-inflammatory activities with significantly reduced ulcerogenicity compared to the parent drug.


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