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The effect of intraventricular infusion of D2-CAM/N-CAM directed antibodies prior to the acquisition of a passive-avoidance paradigm is described. The antisera used in this study were the neuron specific anti-BPM and a D2-CAM/N-CAM specific serum, anti-D2. Anti-BPM reliably inhibited paradigm acquisition when recall was ascertained at 24 and 48 hours and no effect was noted with absorbed anti-BPM or in sham-operated animals. This effect was time-dependent and no inhibition of memory formation was noted when the antiserum was administered at 6 and 10 hours after training. In contrast, infusion of anti-D2 had no effect on paradigm acquisition. These findings are discussed in relation to the potential synaptogenic events associated with memory formation. 相似文献
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Robert A. Lindemann Jean A. Jenkins Robert A. Figlin Sidney H. Golub 《Cancer immunology, immunotherapy : CII》1987,25(2):153-155
Summary A new method was developed for detecting the phenotype of target binding cells (TBC) in a single-cell assay system. This methodology was evaluated during a clinical trial of recombinant interferon alfa-2a (rIFN alfa-2a) for the treatment of 10 metastatic renal cell carcinoma patients. Total TBC with K562 targets, HNK-1+ TBC, and HLA-DR+ TBC were quantitated during rIFN alfa-2a therapy. A significantly increased proportion of lymphocytes bound to target cells on day 9 of therapy bore the HNK-1 marker. This proportion subsequently declined to pretreatment levels. Total TBC paralleled the rise and fall in HNK-1+ TBC. HLA-DR+ TBC binding to targets remained constant and low throughout therapy. These findings suggest that rIFN alfa-2a early in therapy (day 9) caused the recruitment of additional HNK-1+ cells into binders. However, with continued therapy, this proportion reverts to pretreatment levels. The results of this clinical trial served to illustrate the ability of the modified single-cell assay system to detect TBC phenotype.Supported in part by Hoffman-La Roche, NIH grant CA 12582, and Jonsson Comprehensive Cancer Center grant CA 15866Dr. Figlin is a recipient of an American Cancer Society Junior Faculty Fellowship-JFCF 762-A 相似文献
107.
Human elongation factor 1α: a polymorphic and conserved multigene family with multiple chromosomal localizations 总被引:1,自引:0,他引:1
108.
Shio Jean Lin Christine Figueiredo Leonard J. Sciorra Ming-liang Lee 《Human genetics》1987,76(2):173-175
Summary The induction of fragile sites on human chromosomes has been demonstrated under various conditions that cause thymidylate stress, including exposure to uridine. In this study, we examined common fragile site expression by initially exposing peripheral lymphocytes to uridine, followed by repair of the fragile sites with media containing various concentrations of thymidine. Lymphocytes were cultured in medium 199 with 2 mM uridine. At 0.5, 1, 2, 3, 8, 10, 12, and 18 h before harvest, the uridine medium was removed and replaced by medium containing thymidine at various concentrations. Our results demonstrate that the effect of uridine on chromosome fragility can be reversed by low concentrations of thymidine (2 M up to 200 M) and the rescuing effect of thymidine can be achieved if the cells were treated prior to 2–3 h before harvest. No repair was found if thymidine was added to culture within 2 h prior to harvesting, suggesting that packing of chromosomes is also an important factor in the expression and repair of fragile sites. 相似文献
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Catherine Digonnet-Kerhoas Gilles Gay Jean Claude Duplan Christian Dumas 《Planta》1989,179(2):165-170
During ageing of the short-lived pollen grains of Cucurbita pepo L., water loss was examined in relation to viability using biophysical (1H-nuclear magnetic resonance, NMR) and cytological methods (fluorochromatic reaction test, freezefracture and scanning electron microscopy). A semi-logarithmic representation of the pollen weight loss demonstrated the complexity of the dehydration process. A the study of proton loss using 1H-NMR indicated that two major releases water of had taken place, each with different flux rates. Pulse 1H-NMR experiments showed the occurrene of non-exponential signal decay as a function of time, indicating the existence of different fractions of water in a pollen grain sample. These fractions leave the pollen grain at different times during pollen dehydration, and one of them (that of the so-called vital water) can be related to pollen viability. The quantity of protons giving a signal during pulse 1H-NMR experiments was very low when the pollen grains were judged to be dead according to the fluorochromatic test. Freeze-fracture replicas of these dead pollen grains (less than 25% water content) showed that the plasma membrane had become detached from the intine surface; this ultrastructural feature might therefore be involved in the loss of pollen viability.Abbreviations A
initial amplitude of the NMR signal
- A2
quantity of water charcterized by T2-2
- A5
quantity of water characterized by T2–5
- FCR
fluorochromatic reaction
- NMR
nuclear magnetic resonance
- T2
transverse relaxation time
- T2-2
T2 measured with 2 ms between each pulse of radiofrequency
- T2–5
T2 measured with 5 ms between each pulse of radiofrequency 相似文献