Recent Developments in X-Ray Spectrometry

Macdonald, G. L.; Birks, L. S.

doi:10.1080/10408347508542675

Cited by 5 publications

(6 citation statements)

References 187 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on previous analyses of phenotypic changes in T cells during ontogeny, following thymectomy of mice, or as a consequence of cell activation and memory cell generation [15,16,20,, this combinational phenotype presumably contains the naive CD4' cell fraction. In old mice, this cell group is markedly reduced [231 with concomitant increases in CD4' cells expressing high levels of CD44 122,231, a phenotype associated with activated/memory cells [20,34]. However, within the CD44h' fractions of both age groups exists further heterogeneity, including 3G1 lh' CD45RB'" and 3G11" CD45RBbIe cells [231.…”

Section: Discussionmentioning

confidence: 99%

“…For example, CD4' CD45RBh' and CD4' 3Gllh' cells are thought to produce high levels of IL-2 relative to IL-4, whereas increased IL-4 production is associated with the CD45RB1" and 3G11" counterparts [14-16,25,331. In addi-tion, the analysis of cytokine production by CD4' CD44" and CD4' CD44hi cells has revealed that stimulated CD44hi cells produce similar or higher levels of IL-2, and higher levels of IL-3, GM-CSF, and IFNy, compared to CD44" cells [20,34,35]. Thus, under conditions of efficient cell activation (e.g., 2 C l l i or phorbol esters and Ca" ionophores), CD4' cells from old donors can exhibit a cytokine profile commensurate with the existing subset composition.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Cell proliferation and cytokine production by CD4⁺ cells from old mice

Hobbs

Ernst

Torbett³

et al. 1991

J of Cellular Biochemistry

View full text Add to dashboard Cite

Splenocytes from young adult or old C57BL/6NNia mice were stimulated in vitro with the anti-CD3 epsilon mAb, 145-2C11, in either soluble (2C11s) or plate-bound (2C11i) form. In the young group, each mode of cell activation resulted in peak DNA synthesis at approximately 48 h of culture; at this time point, the old group exhibited response levels to 2C11s or 2C11i that were approximately 40% of those in the young group. However, in the presence of 2C11i, splenocytes from old donors showed a delayed peak response which approached the peak levels attained in the young group. To analyze the responsiveness of the CD4+ T cell subpopulation, this cell type was isolated from spleens of young or old mice and was stimulated in vitro with 2C11s or 2C11i, in the presence or absence of added accessory cells (T cell-depleted, irradiated splenocytes). The induction of DNA synthesis by 2C11s was accessory cell dependent, and the response in the old group were markedly reduced in comparison to those in the young group. In contrast, stimulation of DNA synthesis with 2C11i was relatively accessory cell independent, resulted in higher response levels in both age groups, and lessened the disparity between age groups. The analysis of IL-2 and IL-4 secretion by stimulated CD4+ cells revealed that, in response to 2C11s and accessory cells, only IL-2 accumulation was detectable and the levels in the young group were approximately 10-fold higher than the IL-2 levels in the old group. However, stimulation of CD4+ cells with 2C11i and accessory cells yielded improved IL-2 production and a detectable IL-4 response in the old group, whereas the young group exhibited a response profile similar to that induced by 2C11s. Further analysis of the IL-2, IL-4, and IFN gamma mRNA levels in 2C11i-stimulated CD4+ cells revealed that old donor cells accumulated similar levels of IL-2 transcripts, but higher levels of IL-4 and IFN gamma transcripts, than young donor CD4+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Cell proliferation and cytokine production by CD4⁺ cells from old mice

Hobbs

Ernst

Torbett³

et al. 1991

J of Cellular Biochemistry

View full text Add to dashboard Cite

show abstract

“…These assumptions are reasonable and straightforward except, perhaps, assumptions (1) and (5). The water permeability may vary with the vapor pressure, and the helium permeability may be affected by the presence of water in the membrane, but the variation of these permeabilities over the length of the fiber for any given set of experiments may be minimized by reducing the vapor pressure difference in the feed and residue streams.…”

Section: Steady-state Permeation Into Hollow Fibersmentioning

confidence: 99%

Permeation of water vapor through cellulose triacetate membranes in hollow fiber form

Pan¹,

Jensen²,

Bielech³

et al. 1978

J of Applied Polymer Sci

View full text Add to dashboard Cite

SynopsisA modification of the carrier gas method for measuring permeability of a hollow fiber to a vapor is described with particular application to water vapor permeation through asymmetric cellulose triacetate in hollow fiber form. Conventional methods are inadequate because the high flux of permeation vapor combined with its low pressure on the permeate side and the small diameter of the fiber lead to an excessive buildup of pressure in the permeate stream-in.some cases so great as to render much of the fiber length ineffective. The method described in this paper involves the permeation from the outside to the inside of the fiber of a binary mixture consisting of the water vapor and a fairly highly permeable carrier (helium). There is a significant pressure drop along the fiber, but a theoretical treatment is presented to take this into account and to permit a determination of the vapor permeability. Experiments at 35°C over a range of water vapor pressures up to 1.7 cm Hg gave a water flux of 9 X cc(S.T.P.)/cm2-sec-cm Hg, with an apparent slight decrease with increasing pressure. Over the same range of water vapor pressure the helium flux decreased from 2.3 X to 1.85 X cc(S.T.P.)/cm2-sec-cm Hg.

show abstract

“…The analytical techniques include infra-red spectro~copyl-~ c h r~m a t o g r a p h y ,~~~ dehydrochlorination,6 differential refractometry' and cryoscopy. [8][9][10] Of these methods only the last two give results which specify purity, in terms of the y-isomer content, to an accuracy of f O . l % when the sample approaches 100% purity.…”

Section: Introductionmentioning

confidence: 99%

Cryoscopic determination of the purity of lindane

Handley

1960

J. Appl. Chem.

View full text Add to dashboard Cite

A method is described which uses a simple freezing point apparatus and a mercury‐in‐glass thermometer for the determination of the γ‐benzene hexachloride content of samples of lindane. Collaborative results from four co‐operative laboratories showed that the method gives reliable and reproducible results, in good agreement with those found by a differential refractrometric method. A pure reference sample of γ‐benzene hexachloride was prepared by zone‐refining and values for its freezing point and cryoscopic constant measured by a platinum resistance thermometer were in good accord with the data of Toops & Riddick.8

show abstract

Recent Developments in X-Ray Spectrometry

Cited by 5 publications

References 187 publications

Cell proliferation and cytokine production by CD4⁺ cells from old mice

Cell proliferation and cytokine production by CD4⁺ cells from old mice

Permeation of water vapor through cellulose triacetate membranes in hollow fiber form

Cryoscopic determination of the purity of lindane

Contact Info

Product

Resources

About

Recent Developments in X-Ray Spectrometry

Cited by 5 publications

References 187 publications

Cell proliferation and cytokine production by CD4+ cells from old mice

Cell proliferation and cytokine production by CD4+ cells from old mice

Permeation of water vapor through cellulose triacetate membranes in hollow fiber form

Cryoscopic determination of the purity of lindane

Contact Info

Product

Resources

About

Cell proliferation and cytokine production by CD4⁺ cells from old mice

Cell proliferation and cytokine production by CD4⁺ cells from old mice