Hypoxanthine: a low molecular weight factor essential for growth of erythrocyticPlasmodium falciparumin a serum-free medium

SUMMARYA low molecular weight factor in a basal medium essential for erythrocyticPlasmodium falciparumdevelopment in a serum-free medium using a cell growth-promoting factor derived from adult bovine serum was detected. The factor was hypoxanthine. The optimal hypoxanthine concentration for parasite growth was between 15 and 120 μM. The contribution of hypoxanthine to increased parasite growth was clearly evident in cultures on day 4. Among various low molecular weight supplements tested, adenine, adenosine, AMP, ATP, cyclic AMP, guanine, guanosine, inosine, inosine mono-phosphate, xanthine, NAD, NADH, NADP, NADPH and deoxyguanosine triphosphate showed a similar effect to that of hypoxanthine in the serum-free culture system. On the other hand, the addition of uric acid, FAD, thymidine, uridine, orotic acid, deoxythymidine triphosphate, deoxycytidine triphosphate, deoxyadenosine triphosphate, ribose-1-phosphate, or ethanolamine was not beneficial to the parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements of the parasite.

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Continuous cultivation of intraerythrocytic Plasmodium falciparum in a serum-free medium with the use of a growth-promoting factor

Parasitology ◽

10.1017/s0031182000080641 ◽

1994 ◽

Vol 109 (4) ◽

pp. 397-401 ◽

Cited By ~ 26

Author(s):

H. Asahi ◽

T. Kanazawa

Keyword(s):

Plasmodium Falciparum ◽

Bovine Serum ◽

Basal Medium ◽

Parasite Growth ◽

Serum Free Medium ◽

Free Medium ◽

Commercial Preparation ◽

Serum Free ◽

Adult Bovine Serum ◽

Growth Promoting

SUMMARYSerum-free media were used to culture Plasmodium falciparum. A commercial preparation, Daigo's GF21 developed as a growth-promoting factor for many kinds of mammalian cells, and consisting of the 55–70% ammonium sulphate fraction of adult bovine serum, insulin, transferrin, ethanolamine and sodium selenite, was found to sustain growth of the parasite when Daigo's T was employed as a basal medium. The optimal Daigo's GF21 concentration for parasite growth was between 5 and 20% (v/v), with the best results at 10%. Differential counts indicated that Daigo's GF21 is essential for schizogony. Established serum-free medium, GIT, consisting of Daigo's T basal medium and Daigo's GF21, yielded good parasite growth without any supplementation. Growth-promoting factor derived from adult bovine serum in Daigo's GF21 was shown to be crucial to parasite growth. The results presented here will not only be of practical value, but will provide important information about the developmental requirements for the parasite.

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Proliferation of a human embryonal carcinoma-derived cell line in serum-free medium: inter-relationship between growth factor requirements and membrane receptor expression

Journal of Cell Science ◽

10.1242/jcs.73.1.361 ◽

1985 ◽

Vol 73 (1) ◽

pp. 361-373

Author(s):

W. Engstrom ◽

A.R. Rees ◽

J.K. Heath

Keyword(s):

Growth Factor ◽

Cell Line ◽

Embryonal Carcinoma ◽

Density Lipoprotein ◽

Basal Medium ◽

Receptor Expression ◽

Embryonal Carcinoma Cell ◽

Serum Free Medium ◽

Free Medium ◽

Serum Free

Substantial multiplication in vitro of cloned cells from a human embryonal carcinoma cell line, Tera 2, has been obtained in a basal medium (DMEM/Ham's F12,50:50, v/v) supplemented with 10 micrograms low density lipoprotein/ml, 100 micrograms high density lipoprotein/ml, 100 ng multiplication stimulating activity/ml, 100 ng insulin/ml and 1 microgram transferrin/ml. The growth rate appears to be similar to that obtained in 10% serum. Furthermore, studies on the expression of cell surface receptors revealed that cloned Tera 2 cells express high-affinity receptors for IGF-II but not for insulin. The cells also express receptors for Epidermal Growth Factor (EGF) even though the addition of EGF does not stimulate their proliferation in serum-free medium. These results suggest that the expression of specific growth factor receptors is not an absolute determinant of hormone responsiveness.

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Eigenschaften einer niedermolekularen DNA-Fraktion aus embryonalen Rattenzellen in Kultur / Properties of a Low-molecular Weight DNA from Embryonic Rat Cells in Culture

Zeitschrift für Naturforschung B ◽

10.1515/znb-1972-1215 ◽

1972 ◽

Vol 27 (12) ◽

pp. 1507-1515

Author(s):

Rafael Manso-Martinez ◽

Werner Frank

Keyword(s):

Buoyant Density ◽

Sedimentation Coefficient ◽

Low Molecular Weight ◽

Serum Free Medium ◽

Free Medium ◽

Serum Free ◽

Double Stranded Dna ◽

S Period ◽

Cellular Dna

Normal embryonic rat cells, which are synchronized in G1 phase of their cell cycle, by incubation in serum-free medium contain a DNA fraction with a sedimentation coefficient S20 between 11 and 12. This double-stranded DNA shows a significantly higher buoyant density in caesiumchloride than does the bulk of cellular DNA, and its replication is not restricted to a distinct part of the S period. The possible role of these DNA subunits in the replication mechanism is discussed

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Exogeneous factors are not necessary in attachment, spreading and polarization of hela cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082418 ◽

1978 ◽

Vol 36 (2) ◽

pp. 310-311

Author(s):

W. Liebrich

Keyword(s):

Hela Cells ◽

Calf Serum ◽

Glass Tube ◽

Serum Free Medium ◽

Nacl Solution ◽

Free Medium ◽

Minimum Essential Medium ◽

Serum Free ◽

All Solutions ◽

Glass Support

HeLa cells were grown for 2-3 days in EAGLE'S minimum essential medium with 10% calf serum (S-MEM; Seromed, München) and then incubated for 24 hours in serum free medium (MEM). After detaching the cells with a solution of 0. 14 % EDTA and 0. 07 % trypsin (Difco, 1 : 250) they were suspended in various solutions (S-MEM = control, MEM, buffered salt solutions with or without Me++ions, 0. 9 % NaCl solution) and allowed to settle on glass tube slips (Leighton-tubes). After 5, 10, 15, 20, 25, 30, 1 45, 60 minutes 2, 3, 4, 5 hours cells were prepared for scanning electron microscopy as described by Paweletz and Schroeter. The preparations were examined in a Jeol SEM (JSM-U3) at 25 KV without tilting.The suspended spherical HeLa cells are able to adhere to the glass support in all solutions. The rate of attachment, however, is faster in solutions without serum than in the control. The latter is in agreement with the findings of other authors.

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Hemoglobin Enhances the Binding of Bacterial Endotoxin to Human Endothelial Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650565 ◽

1996 ◽

Vol 76 (02) ◽

pp. 258-262 ◽

Cited By ~ 12

Author(s):

Robert I Roth

Keyword(s):

Endothelial Cells ◽

Binding Protein ◽

Bacterial Endotoxin ◽

Dependent Manner ◽

Serum Free Medium ◽

Free Medium ◽

Human Endothelial Cells ◽

Serum Factors ◽

Serum Free ◽

Lps Binding

SummaryHuman endothelial cells, when incubated with bacterial endotoxin (lipopolysaccharide, LPS), modify their surface in association with prominent production of procoagulant tissue factor (TF) activity. This deleterious biological effect of LPS has been shown previously to be enhanced approximately 10-fold by the presence of hemoglobin (Hb), a recently recognized LPS binding protein that causes disaggregation of LPS and increases the biological activity of LPS in a number of in vitro assays. The present study was performed to test the hypothesis that Hb enhances the LPS-induced procoagulant activity of human umbilical vein endothelial cells (HUVEC) by increasing LPS binding to the cells. The binding of 3H-LPS to HUVEC was determined in the absence or presence of Hb or two other known LPS-binding proteins, human serum albumin (HSA) and IgG. LPS binding was substantially increased in the presence of Hb, in a Hb concentration-dependent manner, but was not increased by HSA or IgG. Hb enhancement of LPS binding was observed in serum-free medium, indicating that there was no additional requirement for any of the serum factors known to participate in the interaction of LPS with cells (e.g., lipopolysaccharide (LPS)-binding protein (LBP) and soluble CD14 (sCD14)). Hb enhancement of LPS binding also was observed in the more physiologic condition of 100% plasma. LPS-induced TF activity was stimulated by Hb, but not by HSA or IgG. In serum-free medium, TF activity was not stimulated under any of the conditions tested. Ultrafiltration of LPS was dramatically increased after incubation with Hb but not with HSA or IgG, suggesting that LPS disaggregation by Hb was responsible for the enhanced binding of LPS to HUVEC and the subsequent stimulation of TF activity.

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A study of serum free medium culture on the cloning efficiency of human bone marrow myeloid and erythroid progenitors

Pathology ◽

10.3109/00313029009063553 ◽

1990 ◽

Vol 22 (3) ◽

pp. 145-148 ◽

Cited By ~ 1

Author(s):

Z-H. Wu ◽

L.A. Dowton ◽

G. Georgiou ◽

D.D.F. Ma

Keyword(s):

Bone Marrow ◽

Human Bone ◽

Human Bone Marrow ◽

Cloning Efficiency ◽

Serum Free Medium ◽

Free Medium ◽

Erythroid Progenitors ◽

Serum Free ◽

Medium Culture

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THE INFLUENCE OF SERUM ON THE UPTAKE, CONVERSION AND ACTION OF DIHYDROTESTOSTERONE IN RAT PROSTATE GLANDS IN ORGAN CULTURE

Journal of Endocrinology ◽

10.1677/joe.0.0640289 ◽

1975 ◽

Vol 64 (2) ◽

pp. 289-297 ◽

Cited By ~ 17

Author(s):

ILSE LASNITZKI ◽

HILARY R. FRANKLIN

Keyword(s):

Organ Culture ◽

Horse Serum ◽

Target Tissue ◽

Serum Free Medium ◽

Free Medium ◽

Serum Free ◽

Human Pregnancy ◽

Human Male ◽

Columnar Cells

SUMMARY The influence of serum on the uptake, conversion and action of dihydrotestosterone in relation to the sex steroid binding protein, TeBG, has been investigated in rat ventral prostates in organ culture. The organs were incubated with [1,2-3H]dihydrotestosterone in: (1) serum-free medium, (2) horse serum, foetal and newborn bovine serum or (3) human male and human pregnancy serum. With all sera the uptake of dihydrotestosterone fell with rising serum concentration, at first steeply and then more gradually. At the same concentration, the uptake was significantly lower in explants incubated with human pregnancy serum than in those kept with human male serum. The conversion of dihydrotestosterone to androstanediol followed the same pattern and less androstanediol was formed in the presence of pregnancy serum. Since pregnancy serum contains higher amounts of TeBG than male serum, the lowered uptake suggests that only the free hormone was available to the target organ. Addition of unlabelled dihydrotestosterone resulted in a higher uptake than that measured in explants incubated with the labelled steroid only. The effect of the human sera on uptake and conversion was correlated with the androgenic activity of dihydrotestosterone applied at physiological concentrations and expressed as the percentage of secretory columnar cells present. The degree of maintenance closely corresponded to the uptake of the hormone. In serum-free medium, the number of columnar cells approached the values found in vivo, with male serum their number, though reduced, was still substantial, with pregnancy serum it was extremely low. It is concluded that the amounts of TeBG present in serum regulate the supply of the hormone to the target tissue and thus control its biological action.

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