scholarly journals In vitro mutagenicity testing. I. Kermide 601 resin, Sylgard 184 encapsulating resin, and Sylgard 184 curing agent. [Ames Salmonella assay system used]

1978 ◽  
Author(s):  
S Wang ◽  
D Smith
Keyword(s):  
Assay System ◽  
Curing Agent ◽  
Mutagenicity Testing ◽  
Salmonella Assay

A Comparative Ex Vivo Study of Plasminogen Activators and Proteases for Fibrinolytic Activity and Side Effects in Rabbits

1977 ◽  
Vol 37 (01) ◽  
pp. 154-161 ◽  
Author(s):  
B. A Janik ◽  
S. E Papaioannou
Keyword(s):  
Side Effects ◽  
Effective Dose ◽  
Fibrinolytic Activity ◽  
Ex Vivo ◽  
Plasminogen Activators ◽  
Assay System ◽  
Coagulation Parameters ◽  
Ex Vivo Assay

SummaryUrokinase, streptokinase, Brinase, trypsin, and SN 687, a bacterial exoprotease, have been evaluated in an ex vivo assay system. These enzymes were injected into rabbits and the fibrinolytic activity as well as other coagulation parameters were measured by in vitro techniques. Dose-response correlations have been made using the euglobulin lysis time as a measure of fibrinolytic activity and the 50% effective dose has been determined for each enzyme. Loading doses, equal to four times the 50% effective dose, were administered to monitor potential toxicity revealing that Brinase, trypsin, and SN 687 were very toxic at this concentration.Having established the 50% effective dose for each enzyme, further testing was conducted where relevant fibrinolytic and coagulation parameters were measured for up to two days following a 50% effective dose bolus injection of each enzyme. Our results have demonstrated that urokinase and streptokinase are plasminogen activators specifically activating the rabbit fibrinolytic system while Brinase, trypsin and SN 687 increase the general proteolytic activity in vivo.The advantages of this ex vivo assay system for evaluating relative fibrinolytic potencies and side effects for plasminogen activators and fibrinolytic proteases have been discussed.

In Vitro Mutagenicity Testing of WR6026 Hydrochloride

1994 ◽  
Author(s):  
Barry S. Levine ◽  
Richard H. San ◽  
Patrick D. Curry
Keyword(s):  
Mutagenicity Testing

scholarly journals Colony formation in vitro by leukemic cells in acute lymphoblastic leukemia (ALL)

Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 712-718 ◽  
Author(s):  
SD Smith ◽  
EM Uyeki ◽  
JT Lowman
Keyword(s):  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Bone Marrow Cells ◽  
Lymphoblastic Leukemia ◽  
Lymphoid Cells ◽  
Assay System ◽  
Leukemic Cells ◽  
Specific Cell ◽  
Specific Cell Surface

Abstract An assay system in vitro for the growth of malignant lymphoblastic colony-forming cells (CFC) was established. Growth of malignant myeloblastic CFC has been previously reported, but this is the first report of growth of malignant lymphoblastic CFC. Established assay systems in vitro have been very helpful in elucidating the control of growth and differentiation of both normal and malignant bone marrow cells. Lymphoblastic CFC were grown from the bone marrow aspirates of 20 children with acute lymphoblastic leukemia. Growth of these colonies was established on an agar assay system and maintained in the relative hypoxia (7% oxygen) of a Stulberg chamber. The criteria for malignancy of these colonies was based upon cellular cytochemical staining characteristics, the presence of specific cell surface markers, and the ability of these lymphoid cells to grow without the addition of a lymphoid mitogen. With this technique, specific nutritional requirements and drug sensitivities can be established in vitro, and these data may permit tailoring of individual antileukemic therapy.

scholarly journals Kinetic Analysis of tRNA-Directed Transcription Antitermination of the Bacillus subtilis glyQS Gene In Vitro

2004 ◽  
Vol 186 (16) ◽  
pp. 5392-5399 ◽  
Author(s):  
Frank J. Grundy ◽  
Tina M. Henkin
Keyword(s):  
Bacillus Subtilis ◽  
Assay System ◽  
Nascent Transcript ◽  
Vitro Assay ◽  
T Box ◽  
Transcription Antitermination ◽  
Transcriptional Pausing ◽  
Transcription Complexes ◽  
Kinetics Of

ABSTRACT Binding of uncharged tRNA to the nascent transcript promotes readthrough of a leader region transcription termination signal in genes regulated by the T box transcription antitermination mechanism. Each gene in the T box family responds independently to its cognate tRNA, with specificity determined by base pairing of the tRNA to the leader at the anticodon and acceptor ends of the tRNA. tRNA binding stabilizes an antiterminator element in the transcript that sequesters sequences that participate in formation of the terminator helix. tRNAGly-dependent antitermination of the Bacillus subtilis glyQS leader was previously demonstrated in a purified in vitro assay system. This assay system was used to investigate the kinetics of transcription through the glyQS leader and the effect of tRNA and transcription elongation factors NusA and NusG on transcriptional pausing and antitermination. Several pause sites, including a major site in the loop of stem III of the leader, were identified, and the effect of modulation of pausing on antitermination efficiency was analyzed. We found that addition of tRNAGly can promote antitermination as long as the tRNA is added before the majority of the transcription complexes reach the termination site, and variations in pausing affect the requirements for timing of tRNA addition.

Effect of Granulocytic Chalone on the Growth Rate of Continuous Cell Lines Propagated in Vitro A New Assay System

2009 ◽  
Vol 29 (3) ◽  
pp. 257-264 ◽  
Author(s):  
P. Foa ◽  
A. T. Maiolo ◽  
L. Lombardi ◽  
T. Rytomaa ◽  
E. E. Polli
Keyword(s):  
Growth Rate ◽  
Cell Lines ◽  
Assay System ◽  
Continuous Cell Lines
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