Isolation and partial characterization of a lipopolysaccharide from phase II Coxiella burnetii

1980 ◽  
Vol 26 (7) ◽  
pp. 819-826 ◽  
Author(s):  
Oswald G. Baca ◽  
Irene L. Martinez ◽  
Adam S. Aragón ◽  
David Klassen
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
Coxiella Burnetii ◽  
Complement Fixation ◽  
Fatty Acid Profiles ◽  
Versus Phase ◽  
History Of ◽  
Phenol Water ◽  
Phase I And Ii

A lipopolysaccharide (LPS) was isolated by hot phenol–water extraction from phase II Coxiella burnetii. The LPS was isolated from organisms that had a history of 95 serial yolk sac passages and others that were cloned. The chemical composition of the LPS was partially determined and compared with that of LPS previously isolated from phase I organisms. Most of the sugars present in phase I LPS were detected in phase II LPS; however, there were some quantitative and qualitative differences. The fatty acid profiles of phase I and II LPS were identical. The amount of LPS extracted from phase II organisms was about [Formula: see text] the amount extracted from phase I C. burnetii. Limulus lysate gelation was observed with subnanogram amounts of both phase I and II LPS. In complement fixation tests, both LPSs reacted only with antisera containing antibodies versus phase I antigen. Ouchterlony immunodiffusion tests demonstrated immunological identity of the two LPSs.

scholarly journals Isolation and characterization of a plasmid from phase I Coxiella burnetii.

1983 ◽  
Vol 41 (2) ◽  
pp. 488-493 ◽  
Author(s):  
J E Samuel ◽  
M E Frazier ◽  
M L Kahn ◽  
L S Thomashow ◽  
L P Mallavia
Keyword(s):  
Phase I ◽  
Coxiella Burnetii ◽  
Isolation And Characterization

scholarly journals Ochratoxin A-Induced Hepatotoxicity through Phase I and Phase II Reactions Regulated by AhR in Liver Cells

Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 377 ◽  
Author(s):  
Hye Soo Shin ◽  
Hyun Jung Lee ◽  
Min Cheol Pyo ◽  
Dojin Ryu ◽  
Kwang-Won Lee
Keyword(s):  
Oxidative Stress ◽  
Phase I ◽  
Ochratoxin A ◽  
Phase Ii ◽  
Glutathione Depletion ◽  
Related Factor ◽  
Aryl Hydrocarbon ◽  
Similar Mode ◽  
Phase I And Ii

Ochratoxin A (OTA) is a widespread mycotoxin produced by several species of the genera Aspergillus and Penicillium. OTA exists in a variety of foods, including rice, oats, and coffee and is hepatotoxic, with a similar mode of action as aflatoxin B1. The precise mechanism of cytotoxicity is not yet known, but oxidative damage is suspected to contribute to its cytotoxic effects. In this study, human hepatocyte HepG2 cells were treated with various concentrations of OTA (5–500 nM) for 48 h. OTA triggered oxidative stress as demonstrated by glutathione depletion and increased reactive oxygen species, malondialdehyde level, and nitric oxide production. Apoptosis was observed with 500 nM OTA treatment. OTA increased both the mRNA and protein expression of phase I and II enzymes. The same results were observed in an in vivo study using ICR mice. Furthermore, the relationship between phase I and II enzymes was demonstrated by the knockdown of the aryl hydrocarbon receptor (AhR) and NF-E2-related factor 2 (Nrf2) with siRNA. Taken together, our results show that OTA induces oxidative stress through the phase I reaction regulated by AhR and induces apoptosis, and that the phase II reaction is activated by Nrf2 in the presence of oxidative stress.

scholarly journals Nevirapine Biotransformation Insights: An Integrated In Vitro Approach Unveils the Biocompetence and Glutathiolomic Profile of a Human Hepatocyte-Like Cell 3D Model

2020 ◽  
Vol 21 (11) ◽  
pp. 3998 ◽  
Author(s):  
Madalena Cipriano ◽  
Pedro F Pinheiro ◽  
Catarina O Sequeira ◽  
Joana S Rodrigues ◽  
Nuno G Oliveira ◽  
...  
Keyword(s):  
Phase I ◽  
Phase Ii ◽  
3D Model ◽  
Toxicological Assessment ◽  
Biotransformation Enzymes ◽  
Net Flux ◽  
Hepatotoxic Drug ◽  
Phase I And Ii ◽  
3D Spheroids

The need for competent in vitro liver models for toxicological assessment persists. The differentiation of stem cells into hepatocyte-like cells (HLC) has been adopted due to its human origin and availability. Our aim was to study the usefulness of an in vitro 3D model of mesenchymal stem cell-derived HLCs. 3D spheroids (3D-HLC) or monolayer (2D-HLC) cultures of HLCs were treated with the hepatotoxic drug nevirapine (NVP) for 3 and 10 days followed by analyses of Phase I and II metabolites, biotransformation enzymes and drug transporters involved in NVP disposition. To ascertain the toxic effects of NVP and its major metabolites, the changes in the glutathione net flux were also investigated. Phase I enzymes were induced in both systems yielding all known correspondent NVP metabolites. However, 3D-HLCs showed higher biocompetence in producing Phase II NVP metabolites and upregulating Phase II enzymes and MRP7. Accordingly, NVP-exposure led to decreased glutathione availability and alterations in the intracellular dynamics disfavoring free reduced glutathione and glutathionylated protein pools. Overall, these results demonstrate the adequacy of the 3D-HLC model for studying the bioactivation/metabolism of NVP representing a further step to unveil toxicity mechanisms associated with glutathione net flux changes.

Genomic Analysis of Phase I and II Coxiella burnetii with Restriction Endonucleases

Microbiology ◽  
1985 ◽  
Vol 131 (6) ◽  
pp. 1543-1546 ◽  
Author(s):  
A. T. O'ROURKE ◽  
M. PEACOCK ◽  
J. E. SAMUEL ◽  
M. E. FRAZIER ◽  
D. O. NATVIG ◽  
...  
Keyword(s):  
Phase I ◽  
Coxiella Burnetii ◽  
Genomic Analysis ◽  
Restriction Endonucleases ◽  
Phase I And Ii
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