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821.
Ohne ZusammenfassungMit 2 Textabbildungen. 相似文献
822.
823.
824.
825.
B10.A(3R) (H-2K
b
) mice infected with lymphocytic choriomeningitis virus (LCMV) or vaccinia virus generate cytotoxic T cells capable of specifically lysing virus-infected macrophage target cells fromH-2K
b
mutant mice M505 (H-2K
bd
), and vice versa. Similarly, virus-immune B10.A(4R) (H-2K
k
) T cells specifically lyse infected targets from M523 (H-2K
ka
), and vice versa. In contrast, virus-specific cytotoxic T cells from neither M504 (H-2D
da
) and B10.A(5R) (H-2D
d
) nor M506 (H-2K
fa
) and B10.M(11R) (H-2K
f
) mutually crossreact at the cytotoxic effector-cell level. As far as tested, the crossreactivity patterns between wild-type and mutantK orD specificities are identical for LCMV- and vaccinia virus-immune spleen cells. Although this finding is no proof for either the altered self nor the dual recognition concept of T-cell recognition, it may be compatible with the latter model. 相似文献
826.
Methionine provided in the drinking water of pregnant rats injected with sodium valproate reduced the frequency of resorptions but did not improve embryo growth. Rats drinking methionine supplemented water had approximately twice the level of serum-free methionine and consumed only one-half the volume of water of controls. Using whole rat embryo cultures, the simultaneous addition of methionine and sodium valproate to the medium provided no protection from neural tube defects, nor did the addition of methionine to a medium of serum obtained from rats previously dosed with sodium valproate. However, protection from the teratogenic effects of sodium valproate was afforded by methionine when the culture medium was sera from rats consuming methionine and was particularly striking when embryos for culture were taken from pregnant rats that had been consuming methionine. These observations along with those of others indicated the importance of dietary and culture media methionine levels in evaluating experimental and regulatory teratology studies and suggested the possibility that methionine may play an important role in human teratology where multifactorial causes have been implicated in problems such as neural tube closure defects. 相似文献
827.
Nitrogen and Phosphorus Fractions,Respiration, and Structure of Normal and Crown Gall Tissues of Tomato 总被引:5,自引:4,他引:1 下载免费PDF全文
Klein RM 《Plant physiology》1952,27(2):335-354
828.
829.
C S Irving L Marks P D Klein N Foster P L Gadde T N Chase D Samuel 《Life sciences》1986,38(6):491-495
The ability of adult humans to synthesize taurine was assessed by measurement of the 18O content of urinary taurine in eight subjects following 60 minutes inhalation of 18O2 (97% 18O). All subjects had at least one 3-hour urine collection in which the mole ratio of 18O-taurine to taurine was at least three times greater than the standard deviation of the stable isotope measurement. The peak mole ratios of 18O-taurine/16O-taurine ranged from 0.0075 to 0.015. These data indicated that adult human subjects have a significant ability to synthesize taurine. 相似文献
830.
Ohne Zusammenfassung 相似文献