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31.
Prevention of ultraviolet radiation- or chemical carcinogen-induced morphologic transformation and inhibition of tumor-producing transformed cell growth by lymphotoxin and by normal spleen leukocytes were quantitatively compared to define the antineoplastic activity spectra of these natural immune mediators. When Syrian golden hamster embryo cells seeded for colony formation in culture dishes were treated simultaneously with carcinogen and lymphotoxin, the number of morphologically transformed cell colonies was irreversibly reduced by 50% in the presence of 6 units of lymphotoxin/ml. Lymphotoxin inhibition of tumor cell growth, however, was reversible and 50% reduction in tumor cell growth in three transformed lines required 124, 330, and 477 units/ml. Thus, the anticarcinogenic activity of lymphotoxin can be 20-fold or more greater than its tumor growth-inhibitory activity. Similarly spleen leukocytes also were more effective as an anticarcinogen than as an inhibitor of tumor cell growth, consistent with previous observations that naturally occurring spleen leukocyte antineoplastic activity may result from lymphotoxin secretion.  相似文献   
32.
Presence of mast cell precursors in the yolk sac of mice   总被引:3,自引:0,他引:3  
Concentration of mast-cell precursors in hematopoietic tissues of mouse embryos was evaluated by a limiting dilution method. Cells from yolk sacs, livers, and bodies of (WB x C57BL/6)F1 (hereafter called WBB6F1)- +/+ embryos were injected directly into the skin of adult WBB6F1-W/Wv mice which were genetically depleted of tissue mast cells. Concentration of mast-cell precursors was calculated from the proportion of injection sites at which mast cells did not appear. Since the concentration of mast-cell precursors in the yolk sac was about 30 times as great as that of embryonic body at Day 9.5 of the pregnancy, the mast-cell precursors seemed to be generated within the yolk sac. The concentration in the yolk sac reached the maximum level at Day 11, and then dropped markedly at Day 13. In contrast, mast-cell precursors increased from Day 11 to Day 15 in the fetal liver. As a result, the concentration of 11-day yolk sacs was comparable to that of 15-day fetal liver. Although intravenous injection of 15-day fetal liver cells (2 x 10(6)) rescued the general mast-cell depletion of WBB6F1-W/Wv mice, the intravenous injection of the same number of 11-day yolk sac cells did not rescue it. In contrast with fetal livers, yolk sacs scarcely contained hematopoietic stem cells which were measured by spleen colony formation. Therefore, the mast-cell precursors of the yolk sac may not originate from such stem cells.  相似文献   
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34.
张竞  刘敏芝 《动物学报》1989,35(3):279-286
用微电极细胞外记录的方法,观察内脏痛、躯体痛和触觉刺激对大鼠丘脑后核(PO)中770个神经元电活动的影响,其中305(38.3%)个对伤害性刺激起反应,103(13.4%)个对触觉刺激起反应。对伤害性刺激反应的神经元中多数对躯体痛和内脏痛刺激均起反应且反应形式相同,少数反应不同或相反,对触觉刺激反应的神经元中多数也对两种伤害性刺激均起反应,只对触觉刺激反应的神经元很少。  相似文献   
35.
Abstract: Early ethanol exposure alters the proliferative activity of glial and neuronal precursors in the developing CNS. The present study tests the hypothesis that ethanol-induced alterations in cell proliferation result from interference with growth factors. An in vitro model of astroglia (C6 astrocytoma cells) was used to study the effects of ethanol on proliferation mediated by basic fibroblast growth factor (bFGF). bFGF stimulated the proliferation of C6 cells. This bFGF-enhanced proliferation was evident by increases in total cell number, DNA synthesis (as measured by [3H]thymidine incorporation), and the number of cells that took up bromodeoxyuridine. A synthetic peptide that specifically blocked the binding of bFGF to its high-affinity receptor completely abolished the proliferation-promoting effect of bFGF. The action of another mitogen for C6 cells, insulin-like growth factor-1, was not affected by this peptide. Therefore, the bFGF-stimulated proliferation was mediated through a specific bFGF receptor. Ethanol inhibited bFGF-mediated proliferation in a concentration-dependent manner. Ethanol concentrations of 100 and 200 mg/dl partially inhibited bFGF-mediated proliferation (by 58 and 74%, respectively), whereas concentrations of ≥400 mg/dl completely abolished the growth-stimulating effect of bFGF. Our data show that ethanol alters proliferative activity of C6 cells by disrupting the action of bFGF. The target of ethanol neurotoxicity is a receptor-mediated activity. bFGF can affect cell proliferation by a non-receptor-mediated intracellular pathway, but ethanol does not have an impact on this pathway.  相似文献   
36.
The overlapping distribution of opioid and cholecystokinin (CCK) peptides and their receptors (μ and δ opioid receptors; CCK-A and CCK-B receptors) in the central nervous system have led to a large number of studies aimed at clarifying the functional relationships between these two neuropeptides. Most of the pharmacological studies devoted to the role of CCK and enkephalins have been focused on the control of pain. Recently the existence of regulatory mechanisms between both systems have been proposed, and the physiological antagonism between CCK and endogenous opioid systems has been definitely demonstrated by coadministration of CCK-B selective antagonists with RB 101, a systemically active inhibitor, which fully protects enkephalins from their degradation. Several studies have also been done to investigate the functional relationships between both systems in development of opioid side-effects and in behavioral responses. This article will review the experimental pharmacology of association of enkephalin-degrading enzyme inhibitors and CCK-B antagonists to demonstrate the interest of these molecules in the management of both pain and opioid addiction. Special issue dedicated to Dr. Eric J. Simon.  相似文献   
37.
白细胞介素-2中枢镇痛作用途径的探讨   总被引:3,自引:0,他引:3  
抗IL-2受体α亚基的单克隆抗体不能阻断IL-2的中枢镇痛作用,以及丧失与IL-2受体β亚基结合能力的IL-2突变体仍具有提高大鼠痛阈的能力,这表明IL-2的中枢镇痛作用并不是通过IL-2受体所介导,亦表示IL-2的免疫和镇痛作用是通过不同的受体途径实现的。加之内源性阿片肽与IL-2分子有着共同的抗原决定基和结构相似性,提示IL-2可以与阿片受体直接结合产生中枢镇痛效应。从放射免疫法测定的IL-2侧脑室注射后不同时间大鼠脑内不同核团的内源性阿片肽含量,推测IL-2的中枢镇痛作用可能还与弓状核、室旁核、蓝斑等核团的β-EP和LEK有关。  相似文献   
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39.
反复电针对慢性痛的累加治疗作用及其机制研究   总被引:22,自引:0,他引:22  
罗非 《生理科学进展》1996,27(3):241-244
本研究从基础和临床两方面观察了反复电针对慢性痛的累加治疗作用,并结合疼痛患者及慢性痛动物模型中几种神经肽的放射免疫测定及相应受体拮抗剂的药理学研究结果,探讨了产生累加效应的可能机制。结果表明,在临床脊髓损伤性痉挛患者,100Hz穴位体表电刺激有效地缓解痉挛并有累加效应;在临床慢性痛患者,2/15Hz变频TENS刺激有效地治疗疼痛并具有累加效应。在关节炎模型大鼠,电针刺激能产生明显的镇痛并具有累加效  相似文献   
40.
As conventional treatments are unsuccessful, the survival rate of stage D3 prostate cancer patients is poor. Reports have suggested the existence of humoral and cell-mediated immunity (CMI) against prostate cancer tumour-associated antigens (TAA). These observations prompted us to treat stage D3 prostate cancer patients with an in vitro produced transfer factor (TF) able to transfer, in vitro and in vivo, CMI against bladder and prostate TAA. Fifty patients entered this study and received one intramuscular injection of 2–5 units of specific TF monthly. Follow-up, ranging from 1 to 9 years, showed that complete remission was achieved in 2 patients, partial remission in 6, and no progression of metastatic disease in 14. The median survival was 126 weeks, higher than the survival rates reported in the literature for patients of the same stage.  相似文献   
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