Lymphocyte fractionation

Mercuric chloride was then tested on human thymocytes and peripheral blood lymphocytes, fractionated according to density [161], and it seemed possible that mercuric chloride was a polyclonal stimulator of human peripheral blood T helper lymphocytes and thymocytes with characteristics of medullary cells. When macrophages were depleted, the stimulation remained at about the... 

This test can be performed with the total peripheral blood lymphocyte population or with individual lymphocyte subpopulations (B lymphocytes, T4 and Tg lymphocytes) isolated from the total human lymphocyte fraction by monoclonal antibody separation. The rate of lymphocyte proliferation under influence of mitogens is measured through determination of the rate of incorporation of H-thymidine into the DNA of the lymphocytes. 

The lymphocyte fraction is separated from heparinized blood by Ficoll gradient centrifugation and the lymphocytes adjusted to a cell density of 10 cells/ml. For prestimulation of the lymphocytes, phytohemagglutinin (PHA-M) or concanavalin A are used as mitogens. The prestimulated lymphocytes together with the substance to be tested are transferred to microtitre plates and incubated for 70 or 80 h. H-thymidine is added and the incubation continued for a further 18 h. The quantity of H-thymidine incorporated is determined by scintillation counting (cpm). Percent stimulation is taken as the difference between the incorporated H-thymi-dine of the test and control incubations, multiplied by 100, and divided by the control value. 

Fi02 Fraction of inspired oxygen HLA Human leukocyte antigen human lymphocyte antigen... 

Cells other than T lymphocytes also appear to be involved in tolerance induction. Depletion of macrophages inhibited tolerance induction and transfer studies with non-T cell fractions from tolerant animals was shown to confer tolerance to naive animals [29] Thus, tolerance induction by low doses of D-penicillamine appears to have a complex mechanism that includes various T cell subsets as well as non-T cells, that may be antigen presenting cells. 

Literature data on cytotoxic effects of photoexcited fullerene C60 are controversial. In the studies on transformed B-lymphocytes of Raji fine, phototoxic action of water-soluble carboxy-C60 was not revealed even upon its concentration of 5 x 10 5 M (Irie et al., 1996). In the study (Kamat et al., 2000) damaging effect of fullerenes C60 in dependence on intensity of irradiation toward CHO cells has been demonstrated. Using microsomal fraction of rat liver that was treated with C -cyclodextrin complex, it was shown that already in 5-30 min after UV-irradiation the accumulation of LPO products occurs that is suppressed by antioxidants like ascorbic acid and a-tocopherol. Similar effect of fullerenes C60 has been revealed in microsomal fraction of the cells of ascitic sarcoma 180 (Kamat et al., 2000). 

Add ficoll-hypaque lymphocyte separation medium to tubes, and carefully layer the plasma fraction over the ficoll-hypaque medium at a final volume ratio of 2 parts ficoll-hypaque 3 parts plasma. If 50-mL conical polypropylene centrifuge tubes are used, add 20 mL of ficoll hypaque to the tube first then layer 30 mL of plasma on top of the ficoll hypaque such that a sharp interface is visible between the two layers. 

The majority of micronuclei formed in this study were kinetochore negative, indicating a predominantly clastogenic effect of deoxycholic acid in these cells. Clastogenicity has previously been reported for organic fractions from human faeces and for ursodeoxycholic acid, utilising Chinese hamster ovary cells and human lymphocytes. 

Relative to concentrations of other protein fractions in patients with normal cytological and biochemical flndings and in cases with the lymphocytic cytological... 

In patients with lymphocytic CSF cytological syndromes, elevation of CSF C4 concentrations was observed. Leakage of several proteins across the blood-CSF barrier was also found. Leakage of C4 complement into CSF depends on the functional state of the barrier to a certain extent, being partially selective. Under pathological circumstances, the rate of penetration of protein fractions across the blood-CSF barrier can be modified selectively, which has been proved in CSF acute-phase reactants. They are highly influenced by the production of cytokines. These considerations evoke the question as to whether similar mechanisms of penetration can be expected in cytokines. Elucidation of the pharmacokinetics of interferons in CSF could substantially influence our approach not only to MS patients but to others as well (A18). 

Thymic factors are naturally occurring substances that promote T-lymphocyte differentiation and differentiation of early stem cells into prothymocytes. Each of the available preparations (e.g., thymic humoral factor, thymosin fraction 5, and thymodulin) are mixtures of several polypeptides isolated from a calf thymus extract. 

In cultured human lymphocytes, the frequency of mutations for thioguanine resistance increases as a linear nonthreshold function of the x-ray dose over the range from 10 to 100 mGy (1 to 10 rad) (see Figure 7.1) and is essentially the same whether the dose is delivered in several fractionated exposures or in a single brief exposure (Grosovsky and Little, 1985). 

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