Effect of media composition on the induction of chorionic gonadotropin by sodium butyrate in HeLa cells

Summary Production of the glycoprotein hormone α-subunit by HeLa cells and its induction by sodium butyrate are dependent on the choice of culture medium. Under identical growth conditions it was found that subunit synthesis in the presence of butyrate was highest in RPMI 1640, lowest in Medium 199 (M199), and intermediate in minimum essential medium (MEM) and Waymouth's MB 752/1. Cell growth was similar in all media examined and was retarded in the presence of butyrate. Alkaline phosphatase activity was also lower in M199 than in RPMI 1640, although, in general, the magnitude of this difference was less than that for the hormone subunit. Incorporation of [1-¹⁴C]butyrate by HeLa cells was simimar in both M199 and RPMI 1640, indicating that uptake and metabolism of the fatty acid were not significantly different under these conditions. In the presence of 3 mM butyrate, mixtures of RPMI 1640 and M199 gave intermediate levels of α-subunit and alkaline phosphatase compared to each medium alone. Intracellular levels of α-subunit as well as that of the culture medium were reduced in M199 compared to RPMI 1640 indicating that synthesis rather than secretion was altered. This work was supported by Grant CA 21534 from the National Institutes of Health, Bethesda, MD.     

Simultaneous identification of T and B cells in blood smears using antibody coated bacteria.

Rabbit lymph nodes produce in vitro more antibodies over longer periods if the culture medium is supplemented with a mixture of horse and fetal bovine serum rather than rabbit serum. Medium RPMI 1640 sustains longer antibody responses and promotes a greater expansion of the cultures than medium 199, both media being supplemented with the serum mixture. Propagation of fast-growing, antibody-producing cultures fed with RPMI 1640 was accomplished by interculture transfer of lymphoid tissue. Round, mostly nonadherent cells grow in RPMI 1640 and medium 199 but in the former a striking proliferation of fibroblast-like cells takes place. This proliferation does not occur in medium 199. Preliminary results indicate that although the fibroblast-like cells do not produce antibodies, they contribute to the response in vitro.     

The influence of culture medium composition on the incidence of chromosomal breakage

Summary In patients with chromosomal instability and in healthy subjects, significant differences were observed in the chromosomal breakage incidence in simultaneous lymphocyte cultures set up with TC Medium 199, Eagle's Minimum Essential Medium, or RPMI 1629. The importance of the choice of culture medium for mutagenicity testing and studied of so-called spontaneous breakage is shown. Cultures incubated with TC Medium 199 showed the highest chromosomal breakage incidence.     

DNA synthesis by cultured lymphocytes: a modified method for measuring 3H-thymidine incorporation

A rapid, convenient and inexpensive method for harvesting lymphocyte cultures and measuring the incorporation of ³H-thymidine into trichloroacetic acid precipitable material has been developed. The basic principle is to adsorb the entire contents of a microculture well onto the cotton applicator portion of a Q-tip, precipitate the DNA, wash away unincorporated ³H-thymidine, and count the remaining ³H in a mixture of scintillation fluid plus detergent. Data presented for mixed lymphocyte cultures between allogeneic rat lymph node cells, mixed lymphocyte cultures of human peripheral blood lymphocytes, Con A stimulated mouse spleen cells, and PHA stimulated mouse spleen cells show the method to be highly reproducible with standard deviations of less than 15% of the mean for quadruplicate mixed lymphocyte cultures and in most cases less than 5% of the mean for duplicate mitogen stimulated cultures. This culture system also gives positive values for PHA stimulated DNA synthetic responses of mouse spleen cells cultured in RPMI-1640 plus penicillin and streptomycin but without exogenous serum.     

Study of the role of iron in the anticryptococcal activity of human serum and fluconazole

Anticryptococcal activity of human serum and apotransferrin in RPMI 1640 was studied in vitro. The effects of varying concentrations of FeCl₃ on this activity was investigated. Possible synergy of serum and apotransferrin with fluconazole was also measured. The fungistatic activity of human serum, whether lyophilized, stored at 4 °C, fresh frozen or purchased from commercial sources vs. Cryptococcus neoformans was comparable. There was no significant loss of fungistatic activity after freezing and thawing the serum up to 10 times. The fungistatic activity of human serum was similar when tested in different tissue culture media with the exception of Medium 199. The addition of apotransferrin (2.0 or 0.2 mg/ml) to RPMI 1640 had an inhibitory effect on cryptococcal growth. This effect was reversed by 20 M of FeCl₃ at both apotransferrin concentrations. By contrast, addition of FeCl₃ to human serum and RPMI 1640 did not reverse inhibition of growth. Fluconazole synergized with the human serum preparations described, but not with pooled commercial serum, for fungicidal activity. Synergistic activity of fluconazole and human serum was not affected by the addition of FeCl₃. Apotransferrin did not show any synergistic fungicidal activity with fluconazole.     

Effects of arachidonic acid and other unsaturated fatty acids on mitogenesis in human lymphocytes.

The effect of fatty acids and other lipids on mitogenic responses in cultured human peripheral blood lymphocytes was studied. Several-fold enhancement of tritiated thymidine incorporation was observed at 0.1 to 5.0 micrograms/ml concentrations of arachidonic acid. Other unsaturated fatty acids produced less marked changes. Increased responsiveness was demonstrable in a variety of media including RPMI 1640 supplemented with 10% fetal calf serum. Changes were also observed in uridine incorporation, total cell number, and blast transformation, indicating that the effect was not on thymidine transport or pool size per se. Arachidonic acid failed to affect PHA binding, indicating that the lectin-cell interaction was not altered. Higher concentrations of fatty acids were inhibitory.     

Evaluation of culture media for effects on cell cycle kinetics and incidence of chromosomal aberrations in human blood cells

Peripheral blood samples from 17 apparently healthy male volunteers were set up in duplicate cultures using three commercially available media: Eagle's MEM, RPMI 1640, and TC 199. BUdR (5-bromo,2-deoxyuridine) (10 micrograms/mL) was added to one of the cultures from each person in each medium after 24 h of culture initiation. All cultures were harvested at 72 h of incubation in the presence of colcemid. RPMI 1640 stimulated the highest mitotic activity in both BUdR-treated and untreated cultures. Higher numbers of first division metaphases corresponded with the higher frequency of chromosome-type aberrations in cultures with Eagle's MEM as compared with RPMI 1640 media. On the other hand, higher numbers of chromatid-type aberrations were present in cultures with TC 199 as compared with those with Eagle's MEM. When the chromosome- and chromatid-type aberration data were pooled to score total cytogenetic abnormalities, an influence of the medium was demonstrable. While cultures with Eagle's MEM and TC 199 had the greater number of first division cells, third of subsequent division cells were most prevalent in RPMI 1640 cultures. It is inferred that the length of the cell cycle, the mitotic index, and to some degree the incidence of spontaneous cytogenetic abnormalities are variable attributes of culture media.     

Effect of arabinosyl cytosine on the level of DNA polymerase and thymidine kinase activity in PHA-stimulated human tonsillar lymphocytes

Summary The effect of arabinosyl cytosine (ara-C) was studied on the uptake, phosphorylation and incorporation of ³H-thymidine in human tonsillar lymphocyte cultures is described along with its effect on the level of DNA polymerase and thymidine kinase activities induced by phytohaemagglutinin (PHA). Freshly isolated tonsillar lymphocytes are stimulated cells with a remarkably high activity of DNA polymerase a and thymidine kinase. During in vitro culture, these stimulated cells are transformed to the resting state with low DNA polymerase and thymidine kinase activity. However, a new DNA synthesising cycle can be induced by PHA with maximum at 48 h.10^–6 M ara-C inhibited the incorporation of ³H-thymidine by 90–95%. This inhibition may be reversed by rinsing the cells. The inhibition of the transport of ³H-thymidine seems to be only a consequence of the inhibitory effect of ara-C on the DNA polymerisation reaction, because at 10 °C, where DNA synthesis was arrested, ara-C does not influence the uptake and the phosphorylation of ³H-thymidine.Ara-C (10^–6 M) abolished also the PHA induced elevation of DNA polymerase a and thymidine kinase activities without influencing protein synthesis of the cell. This supports a coordinated regulation mechanism between DNA synthesis and the synthesis of enzymes involved in DNA replication.     

Long-term in vitro cultivation of Plasmodium berghei

Long-term in vitro culture of Plasmodium berghei was established using the Petri dish candle jar method of Trager and Jensen (1976). Cultures were established at 22, 27 and 37°C. As optimal growth was observed at 27°C, subsequent cultivation was carried out at this temperature. RPMI 1640 medium was modified by incorporating additional glucose (1 mg ml⁻¹) and bactopeptone (1 mg ml⁻¹) in the medium. This medium was found suitable for maintenance of mouse erythrocytes in vitro. P. berghei cultures were maintained using candle jars and this modified RPMI 1640 medium for 45 weeks.     

Light-dependent generation of reactive oxygen species in cell culture media

Cell culture media (RPMI 1640, Dulbecco’s Minimal Essential Medium and yeast extract-peptone-glucose medium) were found to oxidize dichlorodihydrofluorescein diacetate and dihydrorhodamine 123, and to generate spin adduct of 5,5′-dimethyl-1-pyrroline N-oxide, which indicates formation of reactive oxygen species (ROS). The production of ROS was light dependent. The main component of the media responsible for the generation of ROS was riboflavin, but tryptophan, tyrosine, pyridoxine, and folic acid enhanced the effect of riboflavin. These observations point to exposure of cells to ROS under in vitro culture conditions.     

The growth of Vero cells in suspension as cell-aggregates in serum-free media

Vero cell lines, usually considered anchorage-dependent, could be grown as cell-aggregates in suspension culture with serum-free media. Several different combinations of base media gave growth results above 10⁶ cells/ml (NCTC 135:SFRE 199-1; NCTC 135:Waymouth MB 752/1; NCTC 135:RPMI 1640). Insulin was not essential for growth and Bovine Serum Albumin could be diluted out of the media if linoleic acid was present. The size and density of the aggregates formed varied depending on the media used.     

Kinetics of uptake and distribution of arachidonic acid by rat alveolar macrophages

The time course of uptake and distribution of ³H-arachidoni acid (³H-AA) into rat alveolar macrophage phospholipid pools was examined. Macrophages incubated with exogenous ³H-AA in RPMI-1640 containing 0.1% bovine serum albumin (BSA), incorporated this radiolabel into phosphatidylcholine and phosphatidylinositol (PI) with plateau reached within 2 to 4 hours, which remained relatively constant for up to 18 hours. Incorporation of ³H-AA into phospholipid pools revealed that treatment with exogenous 5 nM arachidonic acid had no effect upon pool sizes, but there was a selective incorporation if ³H-AA into PI. Cells were incubated with ³H-AA in RPMI alone or medium containing either 0.2% lactalbumin, fetal calf serum at variable concentrations, 10% Nu, Serum, or 0.1% BSA. Incubation of macrophages with ³H-AA in RPMI alone or containing 0.2% lactalbumin, resulted in approximately 70% of the radiolabel taken up by the cells being incorporated into triglyceride. The addition of BSA to RPMI-1640 medium was found to facilitate selective uptake of ³H-AA into phospholipids. Approximately 70% of incorporated ³H-AA was releseable through the action of exogenous phospholipase A₂.     

Studies of serum-free medium for the generation of lymphokine-activated killer cells

We examined a serum-free medium (designated as TYI 101) for the generation of lymphokine-activated killer (LAK) cells from human lymphocytes, regional lymph node lymphocytes (RLNL) and peripheral blood lymphocytes (PBL). TYI 101 medium consisted of, in addition to nutrient mixture, transferrin, insulin, fetuin, sodium selenite, 2-mercaptoethanol, o-phosphorylethanolamine, chick egg yolk and porcine kidney extract. These hormones were effective for supporting RLNL proliferation as assessed by (³H)-thymidine uptake. When human lymphocytes from two different sources were cultivated with recombinant interleukin 2 (rIL-2) in TYI 101 medium, LAK activity was generated. In cultures of PBL from a healthy donor, LAK cells were generated in TYI 101 medium as efficiently as in RPMI 1640 medium supplemented with 10% human AB-type serum (RPMI-AB). In cultures of RLNL from lung cancer patients, LAK activity obtained in TYI 101 medium was about sixty-five percent of that in RPMI-AB. However, the addition of a small amount of AB-type serum improved the generation of LAK activity, LAK cell expansion, and cell viability in TYI 101 medium. We conclude that TYI 101 medium can be used for the generation of LAK cells from human lymph node lymphocytes with supplementation of none or only a reduced amount of human serum.Abbreviations IMDM Iscove's Modification of Dulbecco's Medium - rIL-2 recombinant Interleukin - LAK Lymphokine-Activated Killer - RLNL Regional Lymph Node Lymphocytes - PBL Pheripheral Blood Lymphocytes - PBS Phosphate-Buffered Saline - RBC Red Blood Cells - RPMI-AB RPMI 1640 medium supplemented with 10% human AB-type serum Address for offprints: Tsukuba Research Laboratory, Japan Synthetic Rubber Co., Ltd., 25 Miyukigaoka, Tsukuba-shi, Ibaraki, 305 Japan     

The effect of folic acid and/or methionine deficiency on deoxyribonucleotide pools and cell cycle distribution in mitogen-stimulated rat lymphocytes

Abstract. Folate deficiency will induce abnormal deoxynucleoside triphosphate (dNTP) metabolism because folate-derived one-carbon groups are essential for de novo synthesis of purines and the pyrimidine, thymidylate. Under conditions of methionine deprivation, a functional folate deficiency for deoxynucleoside triphosphate synthesis is induced as a result of the irreversible diversion of available folates toward endogenous methionine resynthesis from homocysteine. The purpose of the present study was to examine the effect of nutritional folate and/or methionine deprivation in vitro on intracellular dNTP pools as related to DNA synthesis activity and cell cycle progression. Primary cultures of mitogen-stimulated rat splenic T-cells were incubated in complete RPMI 1640 medium or in custom-prepared RPMI 1640 medium lacking in folic acid and/or methionine. Parallel cultures, initiated from the same cell suspension, were analysed for deoxyribonucleotide pool levels and for cell proliferation. The distribution of cells within the cell cycle was quantified by dual parameter flow cytometric bromodeoxyuridine/propidium iodide DNA analysis which allows more accurate definition of DNA synthesizing S-phase cells than the traditional DNA-specific staining with propidium iodide alone. Relative to cells cultured in complete RPMI 1640 media, the cells cultured in media deficient in folate, methionine or in both nutrients manifested increases in the deoxythymidylate pool and an apparent depletion of the deoxyguanosine triphosphate pool. Both adenosine triphosphate and nicotinamide adenine diphosphate levels were significantly reduced with single or combined deficiencies of folate and methionine. These nucleotide pool alterations were associated with a decrease in the proportion of cells actively synthesizing DNA and an increase in cells in G₂+ M phase of the cell cycle. Folate deprivation in the presence of adequate methionine produced a moderate decrease in DNA synthesizing cells over the 68 h incubation. However, methionine deprivation, in the presence or absence of folate, severely compromised DNA synthesis activity. These results are consistent with the established ‘methyl trap’ diversion of available folates towards the resynthesis of methionine from homocysteine and away from nucleotide synthesis. The data confirm the metabolic interdependence of folic acid and methionine and emphasize the pivotal role of methionine on the availability of folate one-carbon groups for deoxynucleotide synthesis. The decrease in DNA synthesis activity under nutrient conditions that negatively affect nucleotide biosynthesis suggest a possible role for abnormal dNTP metabolism in the regulation of cell cycle progression and DNA synthesis.     

Eimeria tenella: Vitamin Requirements for Development in Primary Cultures of Chicken Kidney Cells

SYNOPSIS. Development of Eimeria tenella was studied in primary cultures of chicken kidney cells maintained in Medium 199 lacking each of the following: vitamin A. biotin, p -aminobenzoic acid, folic acid, nicotinamide, Ca pantothenate, pyridoxine, pyridoxal, riboflavin, thiamin, ascorbic acid, calciferol, α-tocopherol, and menadione. Data obtained concerning numbers of mature schizonts or total numbers of parasites or both indicated that all of the vitamins are needed for 1st- and 2nd-generation schizogony, and all except calciferol and folic acid are needed for gametogony.     

Effect of insulin on folic-acid transport in cultured fibroblasts

Uptake of folic acid was measured in secondary cultures of skin fibroblasts from fetal rats. The cultures were made quiescent by 24 hours preincubation in medium containing 1% serum and subsequent 3 hours preincubation in phosphate buffered saline. The uptake of ³H-folic acid was linear with time during 15 seconds and reached a plateau level at 2–3 minutes. There was no further increase in the intracellular radioactivity until the end of the experiments at 10 minutes. The uptake of folic acid in fibroblasts was not concentrative and proceeded until equilibration with the extracellular concentration. Intracellular metabolic conversion of folic acid was not significant during the time of the experiments (up to 10 minutes). Insulin caused a two-fold increase in the initial rate of folate uptake as determined from the 15 second uptake values. The dose response curves for the insulin effect showed that 85% of the maximal effect was exerted by 1 m?M insulin. A lag period of 7–10 minutes was observed after the addition of insulin and before the effect on folic acid uptake was manifested. Thereafter the effect increased with the time of preincubation with insulin. The concentration dependence of folate uptake yielded non homogeneous curves. At low concentrations of substrate, saturable components were observed while at high concentration (above 5 × 10^?6 M) a linear component was observed. Insulin increased the slope of the linear component and the V_max of the saturable component while the K_m remained unaltered.     

Effect of test medium on in vitro susceptibility testing results for Aspergillus fumigatus

We examined the effect of peptone yeast extract glucose broth (PYG), RPMI 1640 and Antibiotic Medium 3 (M3) on the in vitro susceptibility of clinical isolates (n = 200) of Aspergillus fumigatusto amphotericin B (AMB), itraconazole (ITZ) and voriconazole (VCZ). The MICs (mug/mL) of various antifungal agents (geometric mean plus/minus standard deviation) obtained in PYG, RPMI 1640 and M3, respectively, were as follows; AMB: 1.64 plus/minus 0.92, 0.42 plus/minus 0.21, 0.33 plus/minus 0.16; ITZ: 0.44 plus/minus 0.54, 0.40 plus/minus 0.65, 0.17 plus or minus 0.32; VCZ: 0.70 plus/minus 0.58, 0.29 plus/minus 0.22, 0.36 plus/minus 0.21. Pairwise comparisons of the MICs of AMB, ITZ and VCZ obtained in PYG, RPMI 1640 and M3 showed no significant differences except for AMB in PYG broth compared to those obtained in RPMI 1640 and M3 (p相似文献   

Stimulation of uptake of tritiated thymidine into mouse marrow cells in culture by a factor from L-cell conditioned medium

Uptake of ³H-thymidine into suspension cultures of mouse marrow cells was stimulated by the addition of serum-free conditioned medium harvested from cultures of mouse L-cells. Characterization of the “conditioning factor activity” (CFA) by gel filtration, ion exchange chromatography, velocity sedimentation, polyacrylamide gel electrophoresis and susceptibility to trypsin digestion indicated that the CFA detected by stimulation of ³H-thymidine uptake is the same as the CFA detected previously by its ability to stimulate colony formation by marrow cells in vitro. The ³H-thymidine uptake assay was used to investigate the kinetics of disappearance of CFA as a function of time in the presence of mouse marrow cells. The CFA recoverable from the cultures decreased rapidly during the first day, and approached background levels by the fifth day. There was no evidence of inhibitory substances in the depleted media. Even if the cultures continued to receive fresh conditioned medium at daily intervals, ³H-thymidine uptake decreased sharply after the fifth day, indicating that the marrow cells had lost their capacity to respond to CFA.     

Chromosomal breakage in Crohn's disease: Anticlastogenic effect of D-penicillamine and L-cysteine

Summary The incidence of chromosome breakage was found to be elevated in 42 patients with Crohn's disease. This phenomenon was much more striking in cultures set up with TCM 199 than in cultures set up with RPMI 1629 rich in L-cysteine. The drug D-penicillamine, a close analog of L-cysteine, gave an apparent therapeutic response in several patients and reduced the chromosome breakage frequency in the lymphocytes of these patients in vitro and in vivo.Work supported by grants of CNRS (ER 149), INSERM (U 173) and GEFLUC     

Observations consistent with autocrine stimulation of hybridoma cell growth and implications for large-scale antibody production

Existence of autocrine growth factors (aGFs) may influence the serum requirement for growth of hybridoma cells and thus significantly influence process economics. For the murine hybridoma cell line S3H5/2bA2, critical inoculum density (cID) and serum requirement for growth were inversely related for cultivation in both T flasks and spinner flasks. In spinner flasks, an inoculum density of 10⁶ cells/ml was necessary for the cells to grow in RPMI 1640 medium without serum supplement, and an inoculum density of 10³ cell/ml was necessary in RPMI 1640 medium with 10% serum. In T flasks, where the local cell density is higher than in spinner flasks, an inoculum density of 10⁶ cells/ml was necessary for the cells to grow in RPMI 1640 medium without serum supplement, and an inoculum density of 1 cell/ml was also necessary in RPMI 1640 medium with 10% serum. Further, immobilized cells at high local cell density could grow under conditions where cells in T flasks at corresponding overall cell density could not grow. The cells at high inoculum density were less sensitive to shear induced by mechanical agitation than the cells at low inoculum density. Taken together these observations support the existence of secreted aGF(s) by the hybridoma cell line used. Since the specific MAb production rate was independent of cultivation method and inoculum density, the existence of autocrine growth factors would suggest that the use of immobilized cells should improve the economics of MAb production.