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1.
巨噬细胞免疫调变信号——PKA与PKC对MAPK信号通路的调节   总被引:7,自引:0,他引:7  
以前的研究工作表明,细菌脂多糖(LPS)可以调变抑制性巨噬细胞为增强T、B淋巴细胞及NK细胞活性,同时又能保持或增强其抗肿瘤效应。忆报道了在这一复杂的免疫调变过程中伴随有蛋白激酶C(PKC)和促分裂原活化蛋白激酶(MAPK)信号转导通路的激活。为了探索免疫调变过程中其他信号对MAPK通路的影响,以LPS调变小鼠腹腔抑制性巨噬细胞为模型,研究了cAMP/PKA和佛波酯(PMA)/PKC信号对MAPK  相似文献   

2.
如何从体表电位分布图(BodySurfacePotentialMappings:BSPM)中得到有价值的诊断特征或信息是将BSPM技术应用于临床的重要研究课题之一。基于计算机心脏仿真模型,详细研究了BSPM中能够对陈旧性心肌梗塞的发生部位与范围进行准确诊断的特征与信息。研究结果表明:QRS期间正常BSPM中为正电位、陈旧性心肌梗塞BSPM中为负电位的导联分布区域与出现Q波的导联分布区域是陈旧性心肌梗塞发生部位较准确、可靠的定位信息;可以用正常BSPM为正电位、而梗塞BSPM为负电位的导联区域的面积或导联数来识别陈旧性心肌梗塞的发生范围或大小。  相似文献   

3.
对379例良、恶性肝组织进行的免疫组织化学研究显示,33%的慢性迁延性肝炎(6/18)、76%的慢性活动性肝炎(26/34)、92%的肝硬变(57/62)和97%的肝细胞性肝癌(HCC)(58/60)中有HBxAg表达,阳性率高于HBsAg或HBcAg。癌周肝中的HBxAg阳性率显著高于非癌周肝。与其它2种HBV抗原不同,HBxAg表达在细胞类型上有较明显的选择性,在肝小多角细胞(SPLC)、小细胞性不典型增生(SCD)及HCC中较强。与IGFⅡ、c-erbB-2、c-myc和EGF-R表达进行的对照研究表明HBxAg与IGFⅡ和c-erbB-2这2种HCC发生相关基因的表达关系密切。PCNA染色结果显示HBxAg阳性组织的细胞增殖活性显著高于HBxAg阴性组织。我们的结果还表明HBxAg表达与肝细胞不典型增生的发生和进展有关、提出HBVX基因可能通过其表达产物(HBxAg)首先激活IGFⅡ、c-erbB-2基因,继而引起显著的SPLC增生和SCD而参与HCC发生的.  相似文献   

4.
季晓辉 《微生物与感染》1994,17(4):156-158,161
本文综述国外近年来对单核-巨噬细胞受单纯疱诊病毒(HSV)感染的研究成果。单核-巨噬细胞对HSV感染具有天然的内在抗性,这种抗性受遗传基因控制,不依赖于干扰素(IFN)。单核-巨噬细胞的这种抗性因其组织来源和分化状态的不同而有程度上的差异。佛波酯类(PMA),脂多糖(LPS),α-肿瘤坏死因子(TNF-α)等可削弱这种抗性,促进HSV在单核-巨噬细胞中增殖。  相似文献   

5.
鲤鱼粘液细胞类型的研究   总被引:25,自引:2,他引:23  
以阿新蓝-过磺酸雪夫氏染色方法(AB-PAS)观察了鲤鱼粘液细胞的形态和类型。根据AB-PAS染色结果将鲤鱼粘液细胞分成四型:Ⅰ型为红色,AB阴性,PAS阳性,含中性粘多糖;Ⅱ型为蓝色,AB阳性,PAS阴性,含酸性粘多糖;Ⅲ型为紫红色,AB与PAS均为阳性,同时含有中性粘多糖和酸性粘多糖,但以中性粘多糖为主;Ⅳ型为蓝紫色,AB与PAS均为阳性,同时含中性粘多糖和酸性粘多糖,但以酸性粘多糖为主。  相似文献   

6.
以孕马血清促性腺激素(PMSG)激发的SD大鼠卵巢为模型,用3′-末端原位标记和形态健康卵泡和闭锁卵泡,用原侠杂交方法研究了在卵泡发育和闭锁过程中甾体激素合成快速调节蛋白(StAR)mRNA的表达规律。发现StARmRNA在膜-间质细胞和黄体化颗粒细胞中表达,未黄体化颗粒细胞和卵母细胞均无表达。PMSG注射后12小时卵巢内已有StARmRNA的表达,24小时表达量升高,72小时表达量达高峰。PMS  相似文献   

7.
目的探讨大鼠实验性肝癌发病中刺五加对肌体免疫功能和抗氧化酶活性的影响。方法46只SD雄性大鼠被随机分成对照组(喂普通饲料)、3-甲基4-双甲氨基偶氮苯(3-Me-DAB)组(喂含0.06%3Me-DAB饲料 10周)和刺五加组(饲喂同 3-Me-DAB外、另加入刺五加 4.5g/kg饲料,用常规方法检测全血谷光甘肽过氧化物酶(GSH-PX)、血清超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量,用微量化学发光造检测吞噬细胞活性(PMN-CL)。结果1.PMN-CL检测峰值、积分值和吞噬细胞指数,3-MeDAB组较正常组和刺五加组均有显著升高(P<0.05和P<0.01)2.全血GSH-PX活性、SOD活性,刺五加组较3-MeDAB组均有显著升高(P<0.05)。MDA含量刺五加组和3-MeDAB组均较正常组升高(均P<0.05)。结论刺五加在大鼠实验性肝癌诱发过程中有提高抗氧化酶活性和对抗致癌剂引起的机体中性粒细胞吞噬功能代偿性增高的作用。  相似文献   

8.
给BALB/c小鼠腹腔注射产肠毒素B金黄色葡萄球菌(SEBS)、绿脓杆菌(PA)或葡萄球菌肠毒素B(SEB),均可引起小鼠胸腺萎缩,呈现胸腺重量减轻、胸腺细胞数减少、胸腺细胞存活率降低。实验发现,在这些细菌或毒素作用下,胸腺细胞发生了具有细胞凋亡的特征性形态学和生化学变化。进一步研究表明,小鼠胸腺细胞凋亡的机制可能与这些细菌或毒素诱导宿主产生TNF-α、IFNr和IL-6等细胞因子有关。  相似文献   

9.
猪肾胆绿素还原酶的分离纯化及部分性质的研究   总被引:1,自引:0,他引:1  
猪肾胆绿素还原酶的分离纯化及部分性质的研究张楚富,吴志平,朱汝(武汉大学生命科学学院430072)关键词猪肾胆绿素还原酶,红色三嗪染料-琼脂糖凝胶4B层析,米氏常数在哺乳动物中,胆绿素还原酶(EO1.3.1.24)广泛存在于肝、脾、肾、肌肉和脑等组织...  相似文献   

10.
目的研究半滑舌鳎肝胰、中肾、鳃、头肾、脾和心中酸性磷酸酶(ACP)、碱性磷酸酶(ALP)和过氧化物酶(POX)的分布及组织定位。方法取健康半滑舌鳎肝胰、中肾、鳃、头肾、脾和心组织进行固定,冰冻切片后进行酶组织化学染色和光密度定量统计分析。结果 ACP活性部位为棕色,主要分布于肝胰小叶间胆管和静脉,中肾肾小体中的肾小球和肾间质的肾小管,头肾和脾中的巨噬细胞以及心肌层中,在鳃中未见有分布;ALP活性部位被染为蓝紫色,主要分布于肝胰的胰腺腺泡内,中肾肾间质的肾小管,鳃的鳃丝血管和上皮细胞,脾静脉的管壁处和椭圆体,心外膜和肌膜上以及头肾的血窦腔内皮;POX活性部位被染为茶褐色,主要分布于肝胰小静脉和肝血窦内的血细胞,中肾肾间质的血细胞,鳃的鳃丝血管、鳃小片血窦和上皮细胞,头肾、脾内的血细胞以及心的心肌层和血细胞中。ACP活性由大到小依次为心、肝胰、脾、中肾、头肾;ALP活性由大到小依次为中肾、鳃、头肾、脾、心、肝胰;POX活性由大到小依次为脾、头肾、肝胰、中肾、鳃、心。结论 ACP、ALP和POX在半滑舌鳎6种组织中分布特点不同,其活性大小在不同组织中有显著差异。  相似文献   

11.
Plasmid Rms312, specifying resistance to tetracycline (Tc), chloramphenicol (Cm), streptomycin (Sm), sulfonamide (Su), and mercury chloride (Mer), deletes both Tc and Cm Sm Su Mer determinants at a high frequency in Salmonella typhimurium LT2. S. typhimurium mutants that were stable carriers of Rms312 were isolated by alternate culture of R-bearing cells in a medium containing either tetracycline or chloramphenicol. In one of these mutants the deletion frequency of drug resistance determinants was decreased by about 100-fold not only Rms312, but also in R100, R1, and R6-5. This mutation caused a slight reduction of ultraviolet resistance but did not affect generalized genetic recombination, indicating that the mutation is different from recA. The mutation, designated dor (deletion of r-determinants), was mapped to a position near 57 units in the new linkage map of S. typhimurijm LT2 (K. E. Sanderson and P. E. Hartman, Microbiol. Rev. 42:471-519, 1978). The dor mutation had no effect on IS1-mediated illegitimate deletion, indicating that the dor mutation is different from the del mutation described by Nevers and Saedler (P. Nevers and H. Saedler, Mol. Gen. Genet. 160:209-214, 1978).  相似文献   

12.
Alveolar macrophages (AM) differ from other macrophage (m phi) populations in their profile of eicosanoids synthesized from arachidonic acid (AA)3. Little information is available regarding possible differences in the regulation of AA metabolism among various m phi populations. In our study, we compared the ability of cultured resident rat AM and peritoneal m phi (PM) to release and metabolize AA in response to exogenous activators of protein kinase C (PKC). When stimulated with PMA, prelabeled PM released free [3H]AA in a dose-dependent manner over the concentration range 1 to 100 nM. As assessed by HPLC, PMA-stimulated PM metabolized AA to a variety of predominantly cyclooxygenase products. The dose-dependent synthesis of PGE2 by unlabeled PM stimulated with PMA was confirmed using RIA. The ability of PMA to trigger AA release and metabolism in PM was a function of its capacity to activate PKC, as indicated by the following: 1) an additional activator of PKC, oleoyl acetylglycerol, also triggered PM AA metabolism, whereas phorbol didecanoate, which lacks the ability to activate PKC, did not; 2) two structurally unrelated inhibitors of PKC activation (staurosporine and sphinganine) both abrogated PMA induced AA release in PM; and 3) pretreatment for 18 h with high dose PMA (used to deplete cellular PKC), but not phorbol didecanoate, rendered PM refractory to subsequent PMA stimulation of AA release. In contrast to PM, AM cultured in identical fashion failed to release or metabolize AA in response to either PMA or oleoyl acetylglycerol. PM and AM were also compared for their ability to release extracellular superoxide anion in response to PMA; once again, PM exhibited significantly greater release than did AM. Inasmuch as this unresponsiveness to activation of PKC distinguishes AM from other m phi populations, we conclude that it is a unique consequence of m phi differentiation in the lung. Moreover, because both AA metabolism and the respiratory burst are affected, this refractoriness appears to reflect a defect at some proximal level in PKC-mediated signaling.  相似文献   

13.
Rms 201-12 and Rms 201-46 are R mutants with increased copy number, and are derived from a conjugative plasmid Rms 201 that encodes resistance to five drugs, ampicillin (Apc), tetracycline (Tc), chloramphenicol (Cm), streptomycin (Sm), and sulfonamides (Sa). The mutants expressed increased levels of resistance to Apc, Sm, and Cm, and a decreased level of resistance to Tc than those of the parent Rms 201 plasmid. When the Rms 201-12+ or Rms 201-46+ cells were inoculated onto plates containing a high concentration of Tc, colonies developed on the plate at a frequency of 10-3 to 10-4 after overnight incubation. The cells grown on the Tc plate carried a tet (Tc gene)-deleted R mutant besides tet-possessing Rms 201-12 or Rms 201-46, and we isolated the tet-deleted R mutant by purifying the R+ cells on drug-free plates. On the other hand, various deletion mutants possessing tet were isolated by prolonged culture of the cells. We have presented a circular gene order of Rms 201 by comparing the genetic markers of all deletion mutants derived from Rms 201, Rms 201-46, and Rms 201-12. The gene(s) regulating the copy number was closely linked to the rep gene. The gene(s) specifying entry exclusion was jointly lost with the tra region.  相似文献   

14.
The present study was undertaken to investigate the changes in arachidonic acid (AA) metabolism which accompany rat macrophage (m phi) differentiation in the lung in order to determine whether these changes occur in the alveolar space or in the pulmonary interstitium, as well as the mechanisms responsible for such changes. Metabolism of endogenous and exogenous AA by cultured m phi obtained from the peritoneum (PM), the pulmonary interstitium (IM), and the alveolar spaces (AM) was examined by using HPLC and RIA. Although PM and AM released similar amounts of endogenous AA in response to both ionophore A23187 and the particulate zymosan, PM metabolized AA predominantly to cyclooxygenase (CO) products, whereas AM produced predominantly 5-lypoxygenase (5-LO) metabolites. IM synthesized a profile of eicosanoids which more closely resembled that of PM. Studies of the metabolism of exogenously supplied AA demonstrated that AM indeed had less CO activity than did PM. PM, but not AM, CO activity decreased during prolonged culture in air, suggesting the possibility that oxidative inactivation of CO plays a role in the decline in CO capacity which accompanies m phi differentiation in the lung. In contrast, the greater expression of 5-LO metabolism in AM than PM did not reflect mere differences in enzyme capacity, since upon activation of protein kinase C with PMA or oleoylacetylglycerol, ionophore-stimulated PM produced amounts of 5-LO products which were comparable to the amounts produced by AM stimulated with A23187 alone. These results indicate that increases in 5-LO metabolism and decreases in CO metabolism accompany rat m phi differentiation in the lung, that these changes occur largely in the alveolar space, and that the increased 5-LO capacity and decreased CO capacity are independently regulated by different mechanisms.  相似文献   

15.
Lefebvre B  Batoko H  Duby G  Boutry M 《The Plant cell》2004,16(7):1772-1789
The structural determinants involved in the targeting of multitransmembrane-span proteins to the plasma membrane (PM) remain poorly understood. The plasma membrane H+ -ATPase (PMA) from Nicotiana plumbaginifolia, a well-characterized 10 transmembrane-span enzyme, was used as a model to identify structural elements essential for targeting to the PM. When PMA2 and PMA4, representatives of the two main PMA subfamilies, were fused to green fluorescent protein (GFP), the chimeras were shown to be still functional and to be correctly and rapidly targeted to the PM in transgenic tobacco. By contrast, chimeric proteins containing various combinations of PMA transmembrane spanning domains accumulated in the Golgi apparatus and not in the PM and displayed slow traffic properties through the secretory pathway. Individual deletion of three of the four cytosolic domains did not prevent PM targeting, but deletion of the large loop or of its nucleotide binding domain resulted in GFP fluorescence accumulating exclusively in the endoplasmic reticulum. The results show that, at least for this polytopic protein, the PM is not the default pathway and that, in contrast with single-pass membrane proteins, cytosolic structural determinants are required for correct targeting.  相似文献   

16.
Peritoneal macrophages (PM), obtained from 39 healthy women with normal laparoscopy findings, were stimulated with the ionophore A23187 or/and arachidonic acid (AA) both in adherence and in suspension. AA lipoxygenase metabolites were determined by reversed-phase HPLC. The major metabolites identified were 5-hydroxyeicosatetraenoic acid (5-HETE), leukotriene (LT)B4 and LTC4. The 20-hydroxy-LTB4, 20-carboxy-LTB4, and 15-HETE were not detected. Incubations of adherent PM with 2 microM A23187 induced the formation of LTB4, 110 +/- 19 pmol/10(6) cells, 5-HETE, 264 +/- 53 pmol/10(6) cells and LTC4, 192 +/- 37 pmol/10(6) cells. When incubated with 30 microM exogenous AA, adherent PM released similar amounts of 5-HETE (217 +/- 67 pmol/10(6) cells), but sevenfold less LTC4 (27 +/- 12 pmol/10(6) cells) (p less than 0.01). In these conditions LTB4 was not detectable. These results indicate that efficient LT synthesis in PM requires activation of the 5-lipoxygenase/LTA4 synthase, as demonstrated previously for blood phagocytes. When stimulated with ionophore, suspensions of Ficoll-Paque-purified PM produced the same lipoxygenase metabolites. The kinetics of accumulation of the 5-lipoxygenase/LTA4 synthase products in A23187-stimulated adherent cells varied for the various metabolites. LTB4 reached a plateau by 5 min, whereas LTC4 levels increased up to 60 min, the longest incubation time studied. Levels of 5-HETE were maximal at 5 min, and then slowly decreased with time. Thus, normal PM, in suspension or adherence, have the capacity to produce significant amounts of 5-HETE, LTB4, and LTC4. The profile of lipoxygenase products formed by the PM and the reactivity of this cell to AA and ionophore A23187 are similar to those of the human blood monocyte, but different from those of the human alveolar macrophage.  相似文献   

17.
Regular segregation of composite plasmid Rms201.   总被引:1,自引:1,他引:0       下载免费PDF全文
Copy number mutants Rms201ts15 and Rms201ts16 were isolated at 30 degrees C from a temperature-sensitive replication mutant (Rms201ts14) of the conjugative plasmid Rms201. The numbers of plasmids per chromosome of ML1410(Rms201ts14), ML1410(Rms201ts15), and ML1410(Rms201ts16) grown at 30 degrees C were 2.2, 7.4, and 20, respectively. The synthesis of covalently closed circular plasmid deoxyribonucleic acid stopped in Rms201ts14, Rms201ts15, and Rms201ts16 immediately after a "shift-up" in temperature (42 degrees C). At 42 degrees C, antibiotic-sensitive derivatives appeared after a certain lag time: the lag times of ML1410(Rms201ts14), ML1410(Rms201ts15), and ML1410(Rms201ts16) were 2.5, 5, and 6.8 generations, respectively. After these times, plasmid-positive cells in the populations decreased at a rate of about 50% per generation in all of the mutants. From these results we conclude that plasmid segregation (partition) of Rms201 occurs by regular segregation (partition).  相似文献   

18.
The objective of this study was to determine whether adenosine (ADO) prevents phorbol myristate acetate- (PMA) induced lung injury by modulating peptidoleukotrienes (LT) and/or tumor necrosis factor (TNF) production. PMA significantly increased pulmonary vascular resistance (PVR, 275 +/- 4 to 447 +/- 30 cmH2O.1-1.min) and microvascular filtration coefficient.(Kf, 0.024 +/- 0.002 to 0.040 +/- 0.006 g.min-1.cmH2O-1) in isolated blood-perfused rabbit lungs. ADO (5 mumol/min) blocked the increases in PVR (257 +/- 9 to 283 +/- 26) and Kf (0.028 +/- 0.005 to 0.018 +/- 0.002). After PMA (30 min), perfusate levels of LTC4 + LTD4 increased by 15.3 +/- 2.1 pg/ml; LTE4 increased by 15.1 +/- 4.1 pg/ml. ADO reduced the increase in LTC4 + LTD4 to 2.7 +/- 6.1 pg/ml, but total LT increased by 31.9 +/- 16.6 pg/ml, implying that ADO enhanced the conversion of LTC4 and LTD4 to LTE4. MK-886 (L663,536), an LT synthesis inhibitor, blocked the increase in total LT (6.1 +/- 13.9 pg/ml) but did not reduce the PMA-induced increase in Kf (0.022 +/- 0.003 to 0.035 +/- 0.005) or PVR (238 +/- 11 to 495 +/- 21). After PMA administration, perfusate TNF levels were not different from the 10-fold increase observed in control experiments and were not reduced by ADO or MK-886. TNF production was independent of perfusate blood components and presumably due to low levels of endotoxin in the perfusate (70-90 ng/ml). These results indicate that ADO does not protect against PMA-induced acute lung injury by altering circulating levels of LT or TNF.  相似文献   

19.
A postlavage in situ subpopulation of pulmonary macrophages (PM), biochemically distinct from the lavaged population, has recently been isolated from rats. After exhaustive bronchopulmonary lavage to extract the free lung cells, the lungs were excised, homogenized, and filtered, and the resultant cell suspension was allowed to form a monolayer on plastic Petri dishes. Electron microscopic morphometry failed to indicate any morphologic differences in the two populations. The postlavage in situ PM were more active metabolically during phagocytosis of zymosan particles or stimulation by phorbol myristate acetate (PMA) than the corresponding lavage population, as evidenced by greater superoxide generation. Macrophages prepared by either method became more avidly phagocytic when incubated with cell-free medium isolated in the preparation of the in situ population. Peroxidase, an enzyme absent from the granules of PM separated by lavage techniques, was found in a granule-rich fraction of the in situ macrophage. Catalase activity was found in similar amounts in both supernatants and granule-rich fractions of both populations. The results support the concept of subpopulations of PM and suggest that these subpopulations are distinguished by their biochemical properties and their functional abilities.  相似文献   

20.
Various hydroxyl radical scavengers markedly inhibited phorbol myristate acetate (PMA)-induced lymphotoxin (LT) production by a human T cell hybridoma, AC5-8. Among those we tested, tetramethylurea (TMU) was the most potent scavenger, and it was revealed that TMU must be added before 2 h have elapsed after PMA addition in order for LT production to be inhibited. In concordance with this fact, soluble NADPH dependent O2- forming enzyme(s) were activated several fold by PMA. PMA also induced DNA strand breaks, a process markedly inhibited by TMU. As expected, ADP-ribosyl transferase (ADPRT), which is well known to require DNA strand breaks for its enzymatic activity, was activated by PMA treatment. In addition, specific inhibitors for ADPRT, namely 3-amino-benzamide and nicotinamide, inhibited PMA-induced LT production. Taken together, these three successive events, activation of soluble NADPH dependent O2- forming enzyme(s), DNA strand breaks and activation of ADPRT, may be required for PMA-induced LT production by AC5-8.  相似文献   

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