Lipid metabolism in cultured cells. III. Cholesterol excretion process

1964 ◽  
Vol 207 (6) ◽  
pp. 1221-1225 ◽  
Author(s):  
J. Martyn Bailey
Keyword(s):  
Tissue Culture ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Rabbit Aorta ◽  
Rabbit Serum ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Cholesterol Excretion

Mammalian cells grown in tissue culture have been shown previously to take up considerable quantities of cholesterol from the growth medium. When cells grown on cholesterol-C14 supplemented medium were transferred to unlabeled medium containing serum, excretion of cholesterol into the outside medium took place. When cell cholesterol was labeled by intracellular synthesis from mevalonate-C14 precursor, it also was excreted readily into the serum medium. This excretion did not take place in serum-free medium and was found to be stimulated by a nondialyzable, thermolabile component of human serum. Horse, chicken, calf, and rabbit serum also showed stimulation ability. The process of cholesterol excretion appears to be of general occurrence. It was found in both strains of cultured cells examined (mouse fibroblasts and lymphoblasts) and also in strips of rabbit aorta incubated in vitro.

scholarly journals THE REQUIREMENT FOR HYDROCORTISONE IN ANTIBODY-FORMING TISSUE CULTIVATED IN SERUM-FREE MEDIUM

1964 ◽  
Vol 119 (6) ◽  
pp. 1027-1049 ◽  
Author(s):  
Charles T. Ambrose
Keyword(s):  
Culture Medium ◽  
Essential Amino Acids ◽  
Secondary Response ◽  
Rabbit Serum ◽  
Normal Rabbit Serum ◽  
Secondary Antibody ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free

It was previously reported from this laboratory that the secondary antibody response can regularly be elicited in vitro from fragments of rabbit lymph node node cultured in Eagle's medium supplemented with normal rabbit serum. Evidence is now presented that physiological levels of hydrocortisone (0.01 to 1.0 µM) can substitute for serum in the culture medium. However, with the omission of serum, serine (0.1 mM) must be included among Eagle's "essential" amino acids for consistent optimal antibody production. In some experiments the addition of insulin (0.5 unit/ml) and vitamin B12 (0.5 µg/ml) has further enhanced the secondary response in this serum-free medium.

scholarly journals EVIDENCE FOR A CYTOLYTIC FACTOR RELEASED BY MACROPHAGES

1974 ◽  
Vol 140 (4) ◽  
pp. 1085-1096 ◽  
Author(s):  
Haakon Melsom ◽  
Gilla Kearny ◽  
Stanislav Gruca ◽  
Rolf Seljelid
Keyword(s):  
Tissue Culture ◽  
Cytotoxic Activity ◽  
Peritoneal Macrophages ◽  
Culture Conditions ◽  
Low Doses ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free ◽  
Mouse Peritoneal Macrophages

Mouse peritoneal macrophages cultivated in vitro acquire a strong extracellular cytotoxic activity towards isotope labeled syngeneic erythrocytes as demonstrated by isotope release to the medium. This lytic process is mediated by an extremely labile macrophage cytolytic factor (MCF) which is not detected under ordinary tissue culture conditions with serum present in the medium. By the use of serum-free medium containing low doses of 2-mercaptoethanol MCF is stabilized and found to be an easily dialysable, low molecular substance which resists heating at 60°C for 30 min.

scholarly journals Quantification of Internalized Silica Nanoparticles via STED Microscopy

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Henrike Peuschel ◽  
Thomas Ruckelshausen ◽  
Christian Cavelius ◽  
Annette Kraegeloh
Keyword(s):  
Silica Nanoparticles ◽  
Super Resolution ◽  
Engineered Nanoparticles ◽  
Stimulated Emission ◽  
Alveolar Type ◽  
Serum Free Medium ◽  
Free Medium ◽  
Essential Information ◽  
Serum Free

The development of safe engineered nanoparticles (NPs) requires a detailed understanding of their interaction mechanisms on a cellular level. Therefore, quantification of NP internalization is crucial to predict the potential impact of intracellular NP doses, providing essential information for risk assessment as well as for drug delivery applications. In this study, the internalization of 25 nm and 85 nm silica nanoparticles (SNPs) in alveolar type II cells (A549) was quantified by application of super-resolution STED (stimulated emission depletion) microscopy. Cells were exposed to equal particle number concentrations (9.2×1010particles mL−1) of each particle size and the sedimentation of particles during exposure was taken into account. Microscopy images revealed that particles of both sizes entered the cells after 5 h incubation in serum supplemented and serum-free medium. According to thein vitrosedimentation, diffusion, and dosimetry (ISDD) model 20–27% of the particles sedimented. In comparison, 102-103NPs per cell were detected intracellularly serum-containing medium. Furthermore, in the presence of serum, no cytotoxicity was induced by the SNPs. In serum-free medium, large agglomerates of both particle sizes covered the cells whereas only high concentrations (≥ 3.8 × 1012particles mL−1) of the smaller particles induced cytotoxicity.

scholarly journals Cytotoxic Effects In Vitro of Highly Purified Streptolysin O on Mouse Macrophages Cultured in a Serum-Free Medium

1966 ◽  
Vol 92 (4) ◽  
pp. 1150-1153 ◽  
Author(s):  
Robert M. Fauve ◽  
Joseph E. Alouf ◽  
Albert Delaunay ◽  
Marcel Raynaud
Keyword(s):  
Serum Free Medium ◽  
Free Medium ◽  
Cytotoxic Effects ◽  
Serum Free ◽  
Streptolysin O ◽  
Mouse Macrophages

Innovative serum-free medium for in vitro cultivation of promastigote forms of Leishmania species

2008 ◽  
Vol 136 ◽  
pp. S150
Author(s):  
Abdalla Hassan Sharief ◽  
Eltahir A. Khalil ◽  
Samia A. Omer ◽  
Hamid S. Abdalla
Keyword(s):  
Leishmania Species ◽  
In Vitro Cultivation ◽  
Serum Free Medium ◽  
Free Medium ◽  
Serum Free

scholarly journals Serum factor requirement for reactive oxygen intermediate release by rabbit alveolar macrophages.

1985 ◽  
Vol 161 (2) ◽  
pp. 392-408 ◽  
Author(s):  
G F Gerberick ◽  
J B Willoughby ◽  
W F Willoughby
Keyword(s):  
Alveolar Macrophages ◽  
Tissue Injury ◽  
Reactive Oxygen ◽  
Rabbit Serum ◽  
Reactive Oxygen Intermediate ◽  
Serum Free Medium ◽  
Free Medium ◽  
Oxygen Intermediates ◽  
Serum Free ◽  
Mediator Systems

Alveolar macrophages (AM) from pathogen-free rabbits were unable to release reactive oxygen intermediates (ROI) unless they were conditioned in serum for 24-48 h before triggering with membrane-active agents. The degree of serum conditioning of AM depended upon the concentration of serum used; optimal ROI release was obtained at or above 7.5% fetal bovine serum (FBS). FBS, autologous rabbit serum, pooled rabbit serum, and pooled human serum were each capable of conditioning AM for release of ROI. Serum conditioning of AM requires synthesis of new protein(s); and the enzyme required for ROI production, NADPH oxidase, was only detectable in serum-conditioned cells. Moreover, serum-conditioned cells lost their ability to release ROI after transfer to serum-free medium, while cells maintained in serum-free medium acquired the capacity to release ROI after their transfer to serum-containing medium, demonstrating the reversibility of the phenomenon. Initial purification data indicate that conditioning is mediated by a discrete serum constituent, which precipitates 40-80% saturated ammonium sulfate, does not bind to Cibacron Blue columns, and has a molecular weight of 30,000 to 50,000, as determined by molecular exclusion chromatography. Unlike gamma interferon, which also enhances ROI release by macrophages, our serum-conditioning factor is not acid labile, retaining 67% of its activity after 120 min incubation at pH 2.0. Moreover, it does not appear to be a contaminating endotoxin, since LPS neither conditioned AM for ROI production, nor triggered ROI production by serum-conditioned AM. We propose that such a conditioning requirement may normally protect the lung against ROI-mediated tissue injury. However, during a pulmonary inflammatory reaction initiated by other mediator systems, the resulting transudation of plasma proteins into the alveolar spaces may condition AM in situ for ROI production.

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