scholarly journals Interacting cell populations in cultures of leukocytes from normal or leukemic peripheral blood

Blood ◽  
1977 ◽  
Vol 49 (2) ◽  
pp. 269-280
Keyword(s):  
Thymidine Incorporation ◽  
Kinetic Studies ◽  
Cell Interaction ◽  
Cell Number ◽  
Cellular Interaction ◽  
Intact Cells ◽  
Quantitative Evidence ◽  
Peripheral Leukocytes ◽  
Limiting Dilution ◽  
Stimulation Of

Kinetic studies in cultures containing 2 X 10(5) peripheral leukocytes from patients with acute myelobastic leukemia revealed extensive, radiation-sensitive increases in thymidine incorporation without parallel increases in cell number. Modest and variable stimulation of 3HTdR incorporation was seen with the addition of either leukocyte- conditioned medium prepared with phytohemagglutin (PHA) or PHA alone. However, using the method of limiting dilution, stimulation was always observed and ranged from 3- to 20-fold in individual patients. By mixing small numbers of intact cells with larger numbers of irradiated autologous cells, quantitative evidence was obtained for a cellular interaction between irradiated, PHA-stimulated populations capable of 3HTdR incorporation. Similar evidence for cell-cell interaction was obtained for normal leukocytes.

scholarly journals Interacting cell populations in cultures of leukocytes from normal or leukemic peripheral blood

Blood ◽  
1977 ◽  
Vol 49 (2) ◽  
pp. 269-280 ◽  
Keyword(s):  
Thymidine Incorporation ◽  
Kinetic Studies ◽  
Cell Interaction ◽  
Cell Number ◽  
Cellular Interaction ◽  
Intact Cells ◽  
Quantitative Evidence ◽  
Peripheral Leukocytes ◽  
Limiting Dilution ◽  
Stimulation Of

Abstract Kinetic studies in cultures containing 2 X 10(5) peripheral leukocytes from patients with acute myelobastic leukemia revealed extensive, radiation-sensitive increases in thymidine incorporation without parallel increases in cell number. Modest and variable stimulation of 3HTdR incorporation was seen with the addition of either leukocyte- conditioned medium prepared with phytohemagglutin (PHA) or PHA alone. However, using the method of limiting dilution, stimulation was always observed and ranged from 3- to 20-fold in individual patients. By mixing small numbers of intact cells with larger numbers of irradiated autologous cells, quantitative evidence was obtained for a cellular interaction between irradiated, PHA-stimulated populations capable of 3HTdR incorporation. Similar evidence for cell-cell interaction was obtained for normal leukocytes.

THE INVERTASE OF THE CORN RADICLE AND ITS ACTIVITY IN SUCCESSIVE STAGES OF GROWTH

1962 ◽  
Vol 40 (1) ◽  
pp. 113-126 ◽  
Author(s):  
J. A. Hellebust ◽  
D. F. Forward
Keyword(s):  
Reducing Sugars ◽  
Sugar Content ◽  
Kinetic Studies ◽  
Invertase Activity ◽  
Cell Number ◽  
Permeability Barrier ◽  
Ph Optimum ◽  
Intact Cells ◽  
Stages Of Growth ◽  
Growing Cell

Segments of the first 10 millimeters of corn radicle tips have been analyzed in terms of invertase activity, cell number, fresh and dry weights, and sugar content. Invertase activity per cell increased 40-fold as the meristematic cell advanced to the stage of most rapid elongation, and again subsided as the cell ceased to elongate and entered the stage of maturation. In the growing cell, the concentration of sucrose remained low while that of reducing sugars increased fivefold.The corn radicle invertase was found to be a β-fructofuranosidase with a Km of 0.006 M and a pH optimum of 4.6. Kinetic studies indicate that there is no change in the nature of the corn radicle invertase during cell growth. Equivalent activities of intact cells or segments and homogenates is consistent with the assumption that the enzyme is located outside the permeability barrier of the cells.

Assessment of the function of the βC-subunit of activin in cultured hepatocytes

2004 ◽  
Vol 287 (2) ◽  
pp. E247-E254 ◽  
Author(s):  
Wataru Wada ◽  
Akito Maeshima ◽  
You-Qing Zhang ◽  
Yoshihisa Hasegawa ◽  
Hiroyuki Kuwano ◽  
...  
Keyword(s):  
Conditioned Medium ◽  
Thymidine Incorporation ◽  
Chinese Hamster ◽  
Adenovirus Vector ◽  
Cell Number ◽  
Cho Cell ◽  
Serum Free ◽  
Free Condition ◽  
Serum Free Condition ◽  
Stimulation Of

We assessed the function of the βC-subunit of activin in hepatocytes. We studied the effect of conditioned medium of Chinese hamster ovary (CHO) cell line stably expressing the βC gene (CHO-βC) on growth of AML12 hepatocytes. We also examined the effect of recombinant activin C and transfection of the βC gene by using adenovirus vector. CHO-βC secreted activin C, a homodimer of the βC, as well as precursors of the βC. The conditioned medium of CHO-βC increased both [3H]thymidine incorporation and the cell number in AML12 cells. It also supported survival of AML12 cells in a serum-free condition. Recombinant human activin C also increased both [3H]thymidine incorporation and the number of AML12 cells. Transfection of AML12 cells with the βC-subunit led to the stimulation of [3H]thymidine incorporation. Analysis of the conditioned medium revealed that the βC-subunit formed a heterodimer with the endogenous βA, the formation of which was dependent on the amount of βC expressed. Recombinant activin C did not affect the binding of 125I-activin A to its receptor or follistatin. These results indicate that activin C stimulates growth of AML12 cells. The βC-subunit modifies the function of the βA-subunit by multiple mechanisms.

scholarly journals Differential regulation of IgG1 and IgE synthesis by interleukin 4.

1988 ◽  
Vol 167 (1) ◽  
pp. 183-196 ◽  
Author(s):  
C M Snapper ◽  
F D Finkelman ◽  
W E Paul
Keyword(s):  
Thymidine Incorporation ◽  
Viable Cell ◽  
Cell Number ◽  
Differential Regulation ◽  
Interleukin 4 ◽  
Second Phase ◽  
Two Phase ◽  
Ige Synthesis ◽  
Stimulatory Factor ◽  
Stimulation Of

IL-4/B cell stimulatory factor-1 is a T cell-derived lymphokine that has been shown to enhance IgG1 and IgE and to suppress IgG3 and IgG2b secretion by B cells stimulated with bacterial LPS. We show here that the stimulation of IgG1 and IgE secretion in response to rIL-4 is differentially regulated. The dose-response curve for IgG1 production is bimodal with peaks at 100 and 10,000 U/ml. IgE production is modest at 100 U/ml and exhibits a progressive enhancement as the IL-4 concentration is increased to 10,000 U/ml, reaching approximately 1 microgram of IgE from an initial cell number of 2 X 10(4). Both of these effects are reversed by monoclonal anti-IL-4 antibody. Neither the enhancing nor suppressing effects of IL-4 can be explained by changes in viable cell yields or [3H]thymidine incorporation. The production of both IgG1 and IgE is controlled by IL-4 in a two-phase manner. During the initial 2 d of culture with LPS, IL-4 action for both IgG1 and IgE production is relatively concentration independent at doses greater than 600 U/ml. This 2-d treatment leads to maximal IgG1 production at day 6 with no further addition of IL-4. Addition of IL-4 during the final 4 d of culture has no effect at concentrations under 100 U/ml. At higher concentrations, IL-4 is strikingly suppressive for IgG1 production. By contrast, little IgE is produced unless IL-4 is present after 2 d of culture and the response is directly dependent on the concentration of IL-4 during this second phase of culture with maximal responses observed at 10,000 U/ml. These differences in IL-4 requirements for IgG1 and IgE production, respectively, may have an important role in the regulation of the synthesis of these isotypes in responses to microbial antigens.

Paracrine interaction between thyrocytes and fibroblasts

1987 ◽  
Vol 116 (1_Suppl) ◽  
pp. S225-S230 ◽  
Author(s):  
R. Gärtner ◽  
G. Bechtner ◽  
D. Stübner ◽  
W. Greil
Keyword(s):  
Cyclic Amp ◽  
Conditioned Medium ◽  
Thymidine Incorporation ◽  
Cell Number ◽  
Igf I ◽  
Weak Stimulation ◽  
Paracrine Interaction ◽  
Dose Dependent ◽  
Medium Dose ◽  
Stimulation Of

Abstract. Cell free supernatants (conditioned medium) of isolated porcine thyroid follicles, stimulated with EGF (5 ng/ml) or TSH (1–1000 μU/ml), were tested for a mitogenic activity for fibroblasts. Whereas TSH-conditioned medium dose-dependently stimulated [3H]thymidine incorporation into DNA of fibroblasts, only a weak stimulation was found with EGF. However, when the changes in cell number were determined, a significant increase was only found with EGF-conditioned medium from thyroid follicles. The cause of this discrepancy is a dose-dependent stimulation of [3H]thymidine incorporation into fibroblasts by cAMP and thyroid hormones. Cyclic AMP, however, does not stimulate growth of fibroblasts. IGF I production is stimulated in fibroblasts by basal as well as EGF stimulated conditioned medium of thyroid follicles. In contrast, TSH-conditioned medium inhibited IGF I production in fibroblasts. Conditioned medium itself is free of detectable IGF I. As IGF I stimulates not only growth of fibroblasts, but also of thyrocytes, we conclude, that conditioned medium from thyrocytes stimulates IGF I production in fibroblasts, which itself stimulates fibroblast and thyrocyte growth.

Effects of Sphingosylphosphorylcholine on Vascular Smooth Muscle Cell Growth and on the Delayed Growth Response Cell Cycle Proteins Cdk2 and Cdc2

Hypertension ◽  
2000 ◽  
Vol 36 (suppl_1) ◽  
pp. 722-722
Author(s):  
Agapios Sachinidis ◽  
Eva Hegele ◽  
Seul Claudia ◽  
Georg Eberhardt ◽  
Stefan Seewald ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Cell Volume ◽  
Muscle Cell ◽  
Protein Level ◽  
Thymidine Incorporation ◽  
Cell Number ◽  
Stimulation Of

P160 Abnormal vascular smooth muscle cell (VSMC) proliferation plays an important pathophysiological role in the development of vascular disease. We examined the effect of Sphingosylphosphorylcholine (SPC) on DNA synthesis ([ 3 H]thymidine-incorporation method), cell number, cell volume, and cell diameter (CASY-1 coulter counter) as well as on the delayed response cell cycle proteins cyclin-dependent kinase2 (Cdk2) and Cdc2 (a serine/threonineprotein kinase) after stimulation of quiescent VSMCs with 5 μg/mL SPC for 2, 4, 6, 8, 12, 14, 16, 18, 20, 24, and 36 h. Cdk2 protein level is reduced when cells are in the G0-phase and its level is increased by the progression from G1- to S-phase upon addition of growth factors. Progression of the cells from the G2-phase (high level of tyrosine15-phosphorylated form of Cdc2) into M-phase is regulated by dephosphorylation of the Tyr15 residue of Cdc2 (34 kDa). Cdc2 phosphorylation status at Tyr15 and Cdk2 protein level were examined by chemiluminescence western blotting analysis using primary antibodies which recognizes Tyr15-phosphorylated Cdc2 and Cdk2 protein, respectively. Stimulation of VSMCs for 12, 14, 16, 18, 20, 24, and 32 h caused a 50±6, 50±11, 143±3, 192±15, 304±32, 221±29 and 245±26% increase in [ 3 H]thymidine incorporation. Stimulation of VSMCs with SPC for 24, and 32 hour resulted in an 8 and 32% increase in cell number. Cell volume and radius was increased by 40 and 11%, respectively. Stimulation of quiescent VSMCs with SPC for 12, 16, 20, 24 and 32 h caused an 7, 51, 50, 76, and 32% increase of Cdk2 level. After stimulation of VSMCs for 20 and 24 h a 91 and 103% increase of Tyr15-phosphorylation, respectively, occurred. An almost complete Tyr15-dephoshorylation occurred after 32 h. We might conclude that SPC is a potent mitogenic and hyperthrophic factor for VSMCs acting through stimulation of Cdk2 and Cdc2.

Chronic hypoxia induces proliferation of cultured mesangial cells: role of calcium and protein kinase C

1997 ◽  
Vol 273 (6) ◽  
pp. F954-F960 ◽  
Author(s):  
Atul Sahai ◽  
Changlin Mei ◽  
Timothy A. Pattison ◽  
Richard L. Tannen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chronic Hypoxia ◽  
Thymidine Incorporation ◽  
Mesangial Cells ◽  
Cell Number ◽  
Glomerular Mesangial Cells ◽  
Kinase C ◽  
Stimulation Of

The effect of hypoxia on the proliferation of cultured rat mesangial cells was examined. To evaluate the underlying signaling mechanisms, the roles of intracellular calcium ([Ca2+]i) and protein kinase C (PKC) were determined. Quiescent cultures were exposed to hypoxia (3% O2) or normoxia (18% O2), and [3H]thymidine incorporation, cell number, [Ca2+]i, and PKC were assessed. Mesangial cells exposed to 28 h of hypoxia exhibited a significant increase in [3H]thymidine incorporation followed by a significant increase in cell number at 72 h in comparison with respective normoxic controls. Hypoxia induced a biphasic activation of PKC, reflected by translocation of the enzyme activity from cytosol to membrane at 1 h, a return to baseline at 4 and 8 h, with subsequent reactivation from 16 to 48 h. In addition, hypoxia-induced proliferation was prevented by a PKC inhibitor 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine (H-7). Cells exposed to hypoxia produced progressive increases in resting [Ca2+]ifrom 15 to 60 min which remain sustained up to 24 h of examination. Verapamil significantly prevented the hypoxia-induced proliferation, and both verapamil treatment and incubations in a calcium-free medium for 1 h blocked the hypoxia-induced stimulation of [Ca2+]ias well as PKC. These results provide the first in vitro evidence that chronic hypoxia induces proliferation of cultured glomerular mesangial cells, which is mediated by the stimulation of [Ca2+]iand the subsequent activation of PKC.

Chronic hypoxia induces LLC-PK1 cell proliferation and dedifferentiation by the activation of protein kinase C

1997 ◽  
Vol 272 (6) ◽  
pp. F809-F815 ◽  
Author(s):  
A. Sahai ◽  
C. Mei ◽  
A. Zavosh ◽  
R. L. Tannen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Chronic Hypoxia ◽  
Thymidine Incorporation ◽  
Cell Number ◽  
Significant Inhibition ◽  
Hypoxic Conditions ◽  
Kinase C ◽  
Atp Levels ◽  
Sustained Activation

The effect of chronic hypoxia on the proliferation and dedifferentiation of LLC-PK1 cells was examined. Cultures were exposed either to hypoxia (3% O2) or normoxia (18% O2), and [3H]thymidine incorporation, cell number, and sodium-dependent glucose (Na/Glc) uptakes were assessed. Cultures exposed to hypoxia for 16 h significantly increased [3H]thymidine incorporation followed by a significant increase in cell number both at 24 and 48 h in comparison with respective normoxic controls. Cultures exposed to 24 and 72 h of hypoxia exhibited significant inhibition of Na/Glc uptake when compared with their respective normoxic counterparts. Significant inhibition of cell ATP levels were observed under hypoxic conditions. Acute reoxygenation of hypoxic cells normalized cell ATP levels without any effect on the Na/Glc uptake. Hypoxia also activated protein kinase C (PKC) at 1 and 4 h followed by a subsequent return to baseline with reactivation at 24 h, which remained sustained up to 72 h, suggesting both acute and sustained activation of PKC. Furthermore, the hypoxia-induced alterations in [3H]thymidine incorporation as well as Na/Glc uptake were mitigated by inhibitors of PKC. These results indicate that chronic hypoxia induces both proliferation and dedifferentiation of LLC-PK1 cells mediated, in part, by the activation of PKC.

scholarly journals A Newly Authenticated Compound from Traditional Chinese Medicine Decoction Induces Melanogenesis in B16-F10 Cells by Increasing Tyrosinase Activity

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Xiu Juan Xin ◽  
Jiahong Zou ◽  
Tao Zou ◽  
Huoli Shang ◽  
Li Yun Sun
Keyword(s):  
Chinese Medicine ◽  
Traditional Chinese Medicine ◽  
Cell Number ◽  
Tyrosinase Activity ◽  
Chinese Traditional Medicine ◽  
Inhibition Rate ◽  
Disease Treatment ◽  
Protein Levels ◽  
Stimulation Of

Vitiligo is a kind of skin dysfunction on melanogenesis. The highly prevalent, chronic, and distinctive complexion changes on patients have imposed enormous psychic and economic burden on both individuals and society. Traditional Chinese Medicine (TCM) is a kind of precious source on chronic disease treatment, including skin dysfunctional diseases. In our previous study, a new compound named apigenin-7-butylene glucoside has been authenticated and purified from a prescription of Chinese traditional medicine formula which has been used clinically in vitiligo treatment. The aim of this work is to evaluate the effects of this compound on melanogenesis using melanoma cell B16-F10 in vitro. The results showed that apigenin-7-butylene glucoside had almost no cytotoxicity on B16-F10 cells within a lower dose of 5.0 μg ml-1 and enhanced the melanin level to about 41% and tyrosinase activity to 1.32-fold when compared with controls. The compound showed minor cytotoxicity to B16-F10 cells at the higher concentration of 10 μg ml-1 and 50 μg ml-1, the inhibition rate was 8.4% and 11.8%, and the melanin level and tyrosinase activity showed a decreased trend because of the lower cell number at the higher concentrations. The results indicated that apigenin-7-butylene glucoside was safe to B16-F10 cells within a lower concentration, <5.0 μg ml-1. Incubated with 5.0 ug ml-1of apigenin-7-butylene glucoside for 48 hours, the mRNA and protein levels of Tyr, Trp-1, and Trp-2 genes were all increased except Mitf in B16-F10 cells. The stimulation of apigenin-7-butylene glucoside on melanogenesis of B16-F10 cells through Tyr, Trp-1, and Trp-2 pathway highlighted the potential usage of the compound in vitiligo treatment.

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