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991.
目的探讨凝血酶参与血管平滑肌细胞(VSMCs)异常增生的时相关系,及pp60c-src在其增生信号传递过程中的作用。方法本实验采用培养大鼠胸主动脉3-10代的VSMCs的单细胞悬液用于实验。用MTS法测凝血酶促VSMCs细胞增殖率。用免疫沉淀测定pp60c-src的活性。结果①0.5(umol/ml)和1.0(umol/ml)两种浓度的凝血酶促VSMCs增殖棚对于对照组.在各时间段均有明显促增殖作用,且二者作用程度相似,呈双峰样改变,增殖峰在1h(P〈0.05)和24h(P〈0.05)。②凝血酶刺激组pp60c-src活性在1h(P〈0.05)及12h(P〈0.05)均明显上升。相对凝血酶组.PP1有效的降低了凝血酶诱导VSMCs1h峰值(P〈0.05)及24h的峰值(P〈0.05)。结论①凝血酶促VSMCs的增殖在时间上呈双峰样改变,提示凝血酶不仅有早期快速促VSMCs的增殖作用,而且有后期促VSMCs的增殖作用。②由于pp60c-src活性第二高峰(12h)在凝血酶促VSMCs第二增殖峰值(24h)之前,提示pp60c-src活性后期的增加参与了凝血酶促VSMCs后期增殖。  相似文献   
992.
目的:探讨着色干皮病(xeroderma pigmentosum,XP)伴发鳞状细胞癌(squamous cell careinoma,SCC)的临床病理特点。方法:采用组织病理学方法对1993年~2004年间收集的XP伴发SCC患者进行分析。结果:4例中,男性1例,女性3例。发病年龄最小1岁,最大4岁,平均2.5岁。并发肿瘤年龄,最小7岁,最大18岁,平均12.8岁。其中有明确近亲婚配者2例(50%)。4例患者临床症状及病理结果均典型。结论:XP为常染色体隐性遗传性皮肤病,是一种癌前病变,以早年并发恶性肿瘤为其特征,其中以鳞状细胞癌和基底细胞癌最为常见。与皮肤损害和紫外线损伤程度密切相关。  相似文献   
993.
三种淫羊藿的总黄酮分极提取物对小鼠免疫功能的影响   总被引:2,自引:0,他引:2  
观察了巫山淫羊藿、柔毛淫羊藿和粗毛淫羊获的总黄酮正丁醇提取物(代号A1、A2、A3)和巫山淫羊藿总黄酮乙酸乙酯提取物(B1)对正常小鼠免疫功能的影响。结果;A1可以明显促进脾脏抗体形成细胞的功能(P<0.05),A2、A3虽也有一定的促进作用,但无统计学意义;4种提取物在体外实验中均没有协同ConA诱导牌细胞增殖作用,只有提取物浓度在100μg/ml时,有一定抑制作用。4种提取物对24小时培养脾细胞存活率无明显影响。  相似文献   
994.
以纤维蛋白凝块为HL-60细胞支持物,将其接种于正常和免疫抑制小鼠肾囊膜下,观察其增殖特性和生长特点。结果HL-60细胞纤维蛋白凝块在免疫排斥反应出现前的正常小鼠肾囊膜下,体积增殖5倍左右;在免疫抑制小鼠肾囊膜下,增殖15倍左右。组织切片发现,在肾囊膜下生长6d细胞密度明显增加,生长细胞沿肾囊膜向四周侵润,肿瘤细胞切面面积明显扩大,且生长细胞仍保持HL-60细胞的形态特点。维甲酸(RA)、维胺酸(RⅡ)及三尖杉酯碱等药物可明显抑制HL-60细胞的生长。  相似文献   
995.
The human mucosal immune system is structurally mature and has all the necessary cellular components to generate an immune response at birth. However, in the absence of dietary antigens and bacterial flora, there are no secondary follicles in the Peyer's patches and virtually no immunoglobulin A plasma cells in the lamina propria. Reactive follicle centers develop after birth but it takes 2 years for mucosal IgA plasma cell density to reach adult levels. T cells are present in the epithelium and lamina propria at birth, albeit at a lower frequency than later in life and there are major differences in phenotype between T cells in fetal intestine and postnatal intestine. There is no information on the impact of the massive antigenic challenge at birth on the mucosal immune system. Well-documented deficiencies in the ability of the blood T cells of the neonate to produce interleukin-4 and interferon-gamma may also occur in the intestine. It is still an open question whether it is better to try to prevent immunological sensitization of the newborn by avoiding potential allergens (i.e. cow's milk), or whether early exposure (as happens when premature infants are given formula feeds) might tolerize the infant. Hydrolysed cow's milk formulae are probably less antigenic than whole cow's milk and have been widely used in the treatment of cow's milk allergy. Some thought is now being given as to whether the prophylactic use of hydrolysates can reduce cow's milk allergy in ‘at-risk’ infants.  相似文献   
996.
Intracellular recording of the rat hippocampal slices was established and usedto analyse the effects of glucocorticoid on resting membrane potential as well as inputresistance of the cells in CA1 and CA2 of hippocampal slices.The results indicate thatwithin 1-2 min the steroid hyperpolarized some of the hippocampal neurons with atendency of increasing the cells' input resistance,suggesting that glucocorticoid caninfluence the function of central neurons in a non-genomic pattern,and the underlyingmechanism involves the change of resting membrane potential.  相似文献   
997.
Specific receptors for bombesin/gastrin releasing peptide (GRP) on the androgen-independent human prostate cancer cell lines PC-3 and DU-145 were characterized. No specific binding of 125I-[Tyr4]-bombesin to the androgen-dependent human prostate cancer cell line LNCaP was detectable. The binding of 125I-[Tyr4]-bombesin to PC-3 and DU-145 cells was found to be time- and temperature-dependent, saturable, and reversible. Scatchard analysis revealed a single class of binding sites with high affinity (Kd 9.8 × 10?11 M for PC-3, and 9.1 × 10-11 M for DU-145 cells at 25°C) and with a binding capacity of 44,000 binding sites/cell and 19,000 binding sites/cell, respectively. Bound 125I-[Tyr4]-bombesin was rapidly internalized by PC-3 cells. The nonhydrolyzable GTP analog GTP-gamma-S caused a dose-dependent inhibition of 125I-[Tyr4]-bombesin binding to PC-3 and DU-145 cells, indicating that a G-protein (guanine nucleotide-binding protein) couples the bombesin receptor to intracellular effector systems. Bombesin and GRP(14-27) inhibited the binding of 125I-[Tyr4]-bombesin to both cell lines in a dose-dependent manner with inhibition constants (Ki of 0.5 nM and 0.4 nM, respectively. Both cell lines express the bombesin/GRP preferring bombesin receptor subtype, since, in displacement studies, neuromedin B was more than 200 times less potent than bombesin and GRP(14-27) in inhibiting the binding of 125I-[Tyr4]-bombesin. Two synthetic bombesin/GRP antagonists, RC-3095 and RC-3110, powerfully inhibited the specific binding of 125I-[Tyr4]-bombesin with Ki 0.92 nM and 0.26 nM on PC-3 cells, and 3.3 nM and 0.89 nM on DU-145 cells, respectively. These findings indicate that the PC-3 and DU-145 human prostate cancer cell lines possess specific high-affinity receptors for bombesin/GRP, and are suitable models for the evaluation of the antineoplastic activity of new bombesin/GRP antagonists in the treatment of androgen-independent prostate cancer. © 1994 Wiley-Liss, Inc.  相似文献   
998.
A 36-year-old male with a history of immature teratoma and embryonal carcinoma of the testis was admitted to the hospital for abdominal pain and fever. A CT scan revealed a large right abdominal mass. The patient's serum alpha-fetoprotein (AFP) was 46.8 ng/ml (reference < 25 ng/ml). Fine-needle aspiration (FNA) of the mass revealed malignant glandular cells. Chemotherapy was instituted, followed by resection of the large abdominal mass. The tumor was grossly encapsulated, consisting of large areas of necrotic, hemorrhagic tissue surrounded by smaller, multiloculated cysts. Microscopically, the tumor had a villoglandular pattern and variably stratified tall columnar cells. A prominent feature of the columnar cells was supranuclear and subnuclear vacuolization. Intracytoplasmic PAS-positive, diastase-resistant hyaline globules were occasionally present. AFP by immunoperoxidase was prominent within the tumor. This recurrence of the previously diagnosed testicular teratoma with embryonal carcinoma represents a yolk sac tumor with components strongly resembling endometrioid carcinoma, a variant only recently described in eight cases of ovarian origin (Clement et al.: Am J Surg Pathol 1987; 11(10):767-778). We believe this is the first reported case of an endometrioid-like variant of testicular yolk sac tumor and also the first report of the FNA cytology findings in this variant.  相似文献   
999.
Leukemic cells from a series of patients with chronic B-lymphocytic leukemia (CLL) were analyzed for their buoyant density on discontinuous Percoll gradients. The density profile varied markedly between different patients and also between samples from different body compartments within the same patient. A good correlation was observed between buoyant density and maturation stage of the leukemic clones as judged by Ig-expression and their reactivity with a panel of monoclonal antibodies. Phorbol-ester-induced changes in the leukemic cells were found to be accompanied by a general decrease in their buoyant density. No correlation between density and clinical parameters such as cell counts, clinical stage and survival could be noted. Buoyant density characterization of leukemic B-cell populations is seen as a useful, rapid and simple marker of compartmentalization within the B-lymphocyte maturation spectrum but its clinical relevance remains to be established.  相似文献   
1000.
Abstract: Preformed, xenoreactive natural antibodies (XNA) and complement (C) are involved in the initiation of vascular rejection of organs transplanted between discordant species, presumably by stimulating donor organ endothelial cells (EC). Although C is known to play a role in the activation of EC, it has not been clear whether the antibodies serve only to anchor the initial components of C, and thus permit the C cascade to proceed, or whether the antibodies themselves deliver a signal to the EC. We have tested affinity-purified human IgM containing XNA (IgM-XNA) for its ability to stimulate in vitro the up-regulation of genes in pig EC. Northern blot analysis shows that IgM, which contains XNA, stimulates mRNA accumulation for certain genes (including IL-8, PAI-1, and ECI-7, a new gene that we have found is associated with EC activation), but not others known to be up-regulated in response to TNF, IL-1 or LPS. Our results show that XNA provide a signal to EC, and thus may themselves participate in activation of EC and consequent vascular rejection.  相似文献   
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