Effect of Metal Allergens on the DNA Synthesis of Unsensitized Guinea Pig Lymphoid Cells Cultured in vitro

1982 ◽  
Vol 69 (1) ◽  
pp. 12-17 ◽  
Author(s):  
K. Nordlind
Keyword(s):  
Guinea Pig ◽  
Dna Synthesis ◽  
Lymphoid Cells ◽  
Cells Cultured

scholarly journals Identity and Proliferation of Small Lymphocyte Precursors in Cultures of Lymphocyte-rich Fractions of Guinea Pig Bone Marrow

Blood ◽  
1971 ◽  
Vol 37 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Y. YOSHIDA ◽  
D. G. OSMOND
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Lymphoid Cells ◽  
Short Term ◽  
Small Lymphocyte ◽  
Undifferentiated Cells ◽  
The Mean ◽  
High Concentrations ◽  
Transitional Cells

Abstract Radioautography with 3H-thymidine was used to examine the proliferative activity of bone marrow lymphoid cells and to identify the precursor cells of small lymphocytes in short-term cultures of lymphocyte-rich marrow fractions. High concentrations of small lymphocytes (nuclear diameters less than 8.0 µ in smears) together with large lymphoid ("transitional") cells (nuclear diameters greater than 8.0 µ) were separated from suspensions of guinea pig bone marrow by centrifugation in linear sucrose-serum density gradients. When such lymphocyte-rich marrow fractions were cultured in vitro the labeling and mitotic indices following either continuous or terminal exposure to 3H-thymidine indicated that the large lymphoid cells were confined mainly to the pre-DNA-synthetic (G1) and early DNA-synthetic (S) phases at first, but proceeded subsequently through S phase and mitosis. From these data tentative values were derived for the in vitro duration of G1 (12 hours) and S (13.7 hours). Further cultures were followed radioautographically after a 1-hour pulse of 3H-thymidine at 6-7 hours of culture. The absolute numbers of labeled large lymphoid cells declined during the subsequent 21 hours but, simultaneously, labeled small lymphocytes appeared and increased progressively in absolute numbers to 44.4 ± 8.1 per cent of the initial numbers of labeled large lymphoid cells. The mean grain count of labeled small lymphocytes was half that of the initially labeled large lymphoid cells. Very few labeled undifferentiated cells other than large lymphoid cells were observed. The results demonstrate that lymphocyte-rich marrow fractions are capable of sustaining the production of small lymphocytes in short-term cultures and that the immediate precursors of marrow small lymphocytes are contained within a population of large lymphoid cells.

Effects of ACTH and ACTH fragments on DNA synthesis in guinea-pig adrenal segments kept in organ culture

1987 ◽  
Vol 115 (3) ◽  
pp. 505-510 ◽  
Author(s):  
N. M. Wulffraat ◽  
H. A. Drexhage ◽  
P. Jeucken ◽  
R. D. van der Gaag ◽  
W. M. Wiersinga
Keyword(s):  
Guinea Pig ◽  
Organ Culture ◽  
Dna Synthesis ◽  
Intermediate Lobe ◽  
Terminal Part ◽  
Terminal Fragment ◽  
Acth Fragments ◽  
Epidermal Growth ◽  
Stimulation Of

ABSTRACT Stimulation of adrenal DNA synthesis by ACTH(1–39) and its fragments ACTH(1–24) (Synacthen) and ACTH(18–39) was investigated. Synthesis of DNA was measured as the increase in the percentage of cells in S-phase (Feulgen densitometry) in guinea-pig adrenal explants kept in organ culture and exposed to the peptides for 5 h at 37 °C. ACTH(1–39) and its C-terminal fragment ACTH(18–39) (corticotrophin-like intermediate lobe peptide) were found to be potent stimulators of in-vitro adrenal DNA synthesis. The dose–response kinetics were biphasic and optimal responsiveness was reached in both instances at 1 fmol/1–10 pmol/l (this biological effect of ACTH(18–39) has hitherto not been described). The N-terminal fragment ACTH(1–24) gave only minimal responses. Thyrotrophin and LH, tested as controls, did not induce adrenal DNA synthesis. Epidermal growth factor was a potent stimulator of adrenal DNA synthesis in vitro. Our data suggest a trophic action of the C-terminal part (ACTH(18–39)) of the corticotrophic molecule. Clear trophic effects were also found for the N-terminal part of the pro-opiomelanocortin molecule N-POC(1–76) (optimum 0·1 nmol/l) and N-POC(51– 62) (optimum 0·1 pmol/l). The latter observations support earlier concepts that this part of the proopiomelanocortin molecule has a stimulatory effect on adrenal DNA synthesis. J. Endocr. (1987) 115, 505–510

scholarly journals Generation of cytotoxic T lymphocytes in vitro. IV. Functional activation of memory cells in the absence of DNA synthesis.

1975 ◽  
Vol 142 (3) ◽  
pp. 622-636 ◽  
Author(s):  
H R MacDonald ◽  
B Sordat ◽  
J C Cerottini ◽  
K T Brunner
Keyword(s):  
T Lymphocytes ◽  
Dna Synthesis ◽  
Cell Number ◽  
Primary Response ◽  
Precursor Cells ◽  
Lymphoid Cells ◽  
Velocity Sedimentation ◽  
Secondary Response ◽  
Ctl Activity

Re-exposure of day 14 mixed leukocyte culture (MLC) cells to the original stimulating alloantigens (secondary response) has previously been shown to result in significant proliferation and in rapid reappearance of high levels of cytolytic T-lymphocyte (CTL) activity within the next 4 days. Moreover, evidence has been presented that CTL precursor cells in day 14 MLC populations, while they derived from cells were large at peak of the primary response (day 4) were themselves small lymphocytes which developed into large CTL after restimulation. In this study, inhibition of DNA synthesis by cytosine arabinoside (ARA-C) was used to investigate whether CTL formation could be dissociated from proliferation during the secondary response. It was found that within the first 24 h after restimulation (a) CTL activity increased 6-to-20-fold, (b) 60-70% of the small T lymphocytes became medium- to large-sized cells, and (c) both events were independent of DNA synthesis. By using two successive cell separations by velocity sedimentation at unit gravity, before and after stimulation of day 14 MLC cells for 24 h in the presence or absence of ARA-C, direct evidence was obtained that small CTL precursor cells developed into large CTL, irrespective of DNA synthesis. The presence of ARA-C for periods longer than 24 h inhibited any further increase in CTL activity, in contrast to a parallel increase in lytic activity and cell number from day 1 to day 4 in control restimulated cultures. Taken together with the finding that 90% of the medium- and large-sized lymphoid cells in control restimulated cultures underwent DNA synthesis within 24 h, these results thus suggest that during a secondary MLC response there is initially a differentiation step leading to the formation of CTL which, although it can be clearly dissociated from DNA synthesis, is under normal conditions followed by proliferation of these effector cells.

Effects of oestradiol-17β and 5α-dihydrotestosterone on guinea-pig prostate smooth muscle cell proliferation and steroid receptor expression in vitro

1994 ◽  
Vol 140 (3) ◽  
pp. 373-383 ◽  
Author(s):  
C Ricciardelli ◽  
D J Horsfall ◽  
P J Sykes ◽  
V R Marshall ◽  
W D Tilley
Keyword(s):  
Smooth Muscle ◽  
Guinea Pig ◽  
Dna Synthesis ◽  
Steroid Receptor ◽  
Inhibitory Effect ◽  
Cell Number ◽  
Mrna Levels ◽  
Plating Density ◽  
Stimulation Of

Abstract Smooth muscle cells (SMCs) are the major cellular component of the prostatic stroma. The aim of this study was to examine the effects of oestradiol-17β (OE2) and 5α-dihydrotestosterone (DHT) on the proliferation of guinea-pig prostate SMCs in vitro. OE2 stimulated SMC DNA synthesis at all concentrations examined. At a plating density of 3·0 × 104 cells/cm2, maximal incorporation of [3H]thymidine (136% of control) was observed after 36 h of treatment with 1 nmol OE2/l. At the same plating density, DHT had an inhibitory effect on SMC DNA synthesis, with maximal effects (73% of control) being observed 24 h after treatment with 1 nmol DHT/l. These effects of OE2 and DHT were prevented by co-incubation with specific steroid receptor antagonists. At a threefold lower plating density (1·0 × 104 cells/cm2), the maximal stimulatory and inhibitory effects of OE2 and DHT were delayed by approximately 24 and 12 h respectively. At the lower plating density, a biphasic effect of DHT was observed on DNA synthesis; DHT was both inhibitory and stimulatory. Maximal inhibition (71% of control) and maximal stimulation (168% of control) were observed after 36 and 134 h treatment with DHT respectively. At the lower plating density, longer term treatment of SMC cultures with OE2 and DHT also resulted in an increase in cell number. After 7 days of treatment with OE2 and DHT, cell number increased by 13% and 12% respectively. When OE, and DHT were added in combination, the short-term inhibitory effect of DHT on SMC DNA synthesis was dominant over the stimulatory effect of OE2. Treatment with DHT for 24 h significantly inhibited OE2-induced stimulation of [3H] thymidine incorporation, irrespective of the prior duration of OE2 treatment. At the lower plating density, OE2 also decreased oestrogen receptor (ER) mRNA levels to 38% of control levels after 24 h of treatment. ER mRNA levels remained repressed until 72 h after treatment with OE2, and returned to control values following 96 h of treatment. Both the androgen-induced inhibition and stimulation of DNA synthesis observed following treatment of SMCs with 1 nmol DHT/l were associated with a reduction in androgen receptor (AR) mRNA levels. At an intermediate time (i.e. 48 h after commencement of treatment with DHT) AR mRNA levels were increased more than twofold over control levels. The increase in AR mRNA levels at 48 h after DHT treatment only occurred in cells plated at the lower density, suggesting that this is an essential requirement for the longer term stimulation of prostatic SMC proliferation by DHT. Journal of Endocrinology (1994) 140, 373–383

Immune response of guinea pig lymphoid cells in vitro

1980 ◽  
Vol 50 (1) ◽  
pp. 216-223 ◽  
Author(s):  
J. Kettman ◽  
S. Ben-Sasson
Keyword(s):  
Immune Response ◽  
Guinea Pig ◽  
Lymphoid Cells

Effects of Various Substances on DNA Synthesis in Guinea-pig Skin in vitro

Nature ◽  
1967 ◽  
Vol 216 (5116) ◽  
pp. 715-716 ◽  
Author(s):  
PATRICIA R. MANN
Keyword(s):  
Guinea Pig ◽  
Dna Synthesis ◽  
Pig Skin
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