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141.
Novel nuclear ribonucleoprotein structural components in the dormouse adrenal cortex during hibernation 总被引:4,自引:0,他引:4
Manuela Malatesta Carlo Zancanaro Monica Tamburini Terence E. Martin Xiang-Dong Fu Peter Vogel Stanislav Fakan 《Chromosoma》1995,104(2):121-128
Adrenocortical cell nuclei of the dormouse Muscardinus avellanarius were investigated by electron microscopic immunocytochemistry in hibernating, arousing and euthermic individuals. While the basic structural constituents of the cell nucleus did not significantly were found in nuclei of hibernating dormice. Lattice-like bodies (LBs), clustered granules (CGs), fibrogranular material (FGM) and granules associated with bundles of nucleoplasmic fibrils (NF) all contained ribonucleoproteins (RNPs), as shown by labeling with anti-snRNP (small nuclear RNP), anti-m3G-capped RNA and anti-hnRNP (heterogeneous nuclear RNP) antibodies. Moreover, the FGM also showed immunoreactivity for the proliferation associated nuclear antigen (PANA) and the non-snRNP splicing factor SC-35. All these nuclear structural components disappeared early during arousal and were not found in euthermic animals. These novel RNP-containing structures, which have not been observed in other tissues investigated so far in the same animal model, could represent storage and/or processing sites for pre-mRNA during the extreme metabolic condition of hibernation, to be quickly released upon arousal. NFs, which had been sometimes found devoid of associated granules in nuclei of brown adipose tissue from hibernating dormice, were present in much higher amouts in adrenocortical cell nuclei; they do not contain RNPs and their role remains to be elucidated. The possible roles of these structures are discussed in the frame of current knowledge of morpho-functional relationships in the cell nucleus. 相似文献
142.
RAPD分析─鉴定柑桔体细胞杂种的快速方法 总被引:64,自引:3,他引:61
肖顺元 Frederick G.Gmitter Jude W.Grosser 黄舒XIAO Shun-Yuan Frederick G.Gmitter Jude W.Grosser HUANG Shu 《遗传》1995,17(4):40-42
本文利用改进的DNA提取方法,从Volkamer柠檬(Citrus volkameriana Ten. and Pasq.)和酸橙(C. aurantium L.)及其原生质体杂种植株的叶片中抽提总DNA,进行RAPD(Random Amplified Polymorphic DNA)分析。结果表明: 在随机选取的15种引物中,有10种可单独或与其它引物一道鉴定这一组合的体细胞杂种。与形态学性状观察、同工酶及ONA杂交分析等方法比较,RAPD分析是一种可在试管苗期即可直接、准确、快速鉴定柑桔体细胞杂种的方法。 相似文献
143.
H.C. Chan S.H. Law P.S. Leung L.X.M. Fu P.Y.D. Wong 《The Journal of membrane biology》1997,156(3):241-249
The β-adrenergic (cAMP-dependent) regulation of Cl− conductance is defective in cystic fibrosis (CF). The present study explored alternative regulation of anion secretion in
CF pancreatic ductal cells (CFPAC-1) by angiotensin II (AII) using the short-circuit current (I
SC
) technique. An increase in I
SC
could be induced in CFPAC-1 cells by basolateral or apical application of AII in a concentration-dependent manner (EC50 at 3 μm and 100 nm, respectively). Angiotensin receptor subtypes were identified using specific antagonists, losartan and PD123177, for AT1 and AT2 receptors, respectively. It was found that losartan (1 μm) could completely inhibit the AII-induced I
SC
, whereas, PD123177 exerted insignificant effect on the I
SC
, indicating predominant involvement of AT1 receptors. The presence of AT1 receptors in CFPAC-1 cells was also demonstrated by immunohistochemical studies using specific antibodies against AT1 receptors. Confocal microscopic study demonstrated a rise in intracellular Ca2+ upon stimulation by AII indicating a role of intracellular Ca2+ in mediating the AII response. Depletion of intracellular but not extracellular pool of Ca2+ diminished the AII-induced I
SC
. Treatment of the monolayers with a Cl− channel blocker, DIDS, markedly reduced the I
SC
, indicating that a large portion of the AII-activated I
SC
was Cl−-dependent. AII-induced I
SC
was also observed in monolayers whose basolateral membranes had been permeabilized by nystatin, suggesting that the I
SC
was mediated by apical Cl− channels. Our study indicates an AT1-mediated Ca2+-dependent regulatory mechanism for anion secretion in CF pancreatic duct cells which may be important for the physiology
and pathophysiology of the pancreas.
Received: 17 June 1996/Revised: 14 November 1996 相似文献
144.
145.
四川地区幼儿和学龄前儿童的鼻部测量 总被引:2,自引:0,他引:2
本文报告1116例四川地区幼儿和学龄前儿童(2-7岁)鼻部9项指标的测量均数,性差及年龄发育特点。性差:仅鼻凹鼻底距4-6.5岁等少数指标部分年龄段男女性间出现显著性划异(男>女)。此外各项指标的绝大多数年龄段男女性间无显著性差异。年龄发育:9项测量指标中7项的生长曲线随年产长而上升,数值随年龄增大,并有1-2个发育高峰;提示鼻部发育具有阶段性;2项指标的曲线随年龄增长变化较小。4项指标男女性的曲 相似文献
146.
综述了近年来有关利用基因转移技术修饰肿瘤细胞制备肿瘤基因工程疫苗的最新研究进展,着重阐述了逆转录病毒载体介导的基因转移及其安全性;归纳了目前可用于肿瘤基因工程疫苗的各种目的基因的特点及作用并对这类肿瘤疫苗制备过程中所存在的问题进行了分析. 相似文献
148.
溶剂极性及盐酸胍对碳酸酐酶构象的影响 总被引:1,自引:0,他引:1
以紫外荧光光谱为检测手段,比较研究了溶剂极性及盐酸胍对碳酸酐酶构象的影响,结果表明,当盐酸胍浓度小于1mol/L时酶呈天然构象,1.5mol/L-2.0mol/L的盐酸胍导致该酶呈伸展构象;而乙醇不以导致该酶产生稳定的中间态构象,1mol/L和3mol/L的甲醇以及3mol/L的乙醇对盐酸胍致碳酸酐酶中间态的影响不大,甲醇略使致中间态的盐酸胍浓度下降,乙醇略使之上升。 相似文献
149.
Shu’a Yagev Michael Heller Arié Pinson 《In vitro cellular & developmental biology. Plant》1984,20(12):893-898
Summary Postnatal rat heart cells in culture enriched with respect to muscle cells were obtained by either high density seeding or
by the replating technique. [3H]Thymidine incorporation to DNA and the enzymatic pattern of cytoplasmic and lysosomal enzymes have been studied as a function
of the culture’s age, of seeding density, and replating. It was shown that (a) replating maintains predominance of myocyte
population for at least 2 wk in culture; (b) heavy seeding density allows homogeneous myocyte population for the 1st wk in
culture; and (c) the enzyme profile of the culture may serve as an indicator for the type of cell population in culture and
its state of differentiation.
This study was done as partial fulfilment of the M.Sc. thesis in Biochemistry (SY). Supported by grants from The Chief Scientist,
Ministry of Health, State of Israel; The Ministry of Education and Sciences, State of Niedersachssen (FRG); and The Foundation
for Heart Research from Mr. and Mrs. D. Vidal-Madjar, Paris, France. 相似文献
150.
F.M.A.H. Schuurmans Stekhoven H.G.P. Swarts Y.-F. Fu G.A.J. Kuijpers J.J.H.H.M. de Pont S.L. Bonting 《生物化学与生物物理学报:生物膜》1984,774(2):277-287
(1) Treatment of from rabbit kidney outer medulla with the labeled thio-analogue of ATP in the presence of and the absence of K+ leads to thiophosphorylation of the enzyme. The value for [γ-S]ATP is 2.2 μM and for Na+ 4.2 mM at 22°C. Thiophosphorylation is a sigmoidal function of the Na+ concentration, yielding a Hill coefficient . (2) The thio-analogue () can also support overall activity, but at 37°C is only h?1 or 0.09% of the specific activity for ATP (). (3) The thiophosphoenzyme intermediate, like the natural phosphoenzyme, is sensitive to hydroxylamine, indicating that it also is an acylphosphate. However, the thiophosphoenzyme, unlike the phosphoenzyme, is acid labile at temperatures as low as 0°C. The acid-denatured thiophosphoenzyme has optimal stability at pH 5–6. (4) The thiophosphorylation capacity of the enzyme is equal to its phosphorylation capacity, indicating the same number of sites. Phosphorylation by ATP excludes thiophosphorylation, suggesting that the two substrates compete for the same phosphorylation site. (5) The (apparent) rate constants of thiophosphorylation (0.4 s?1 vs. 180 s?1), spontaneous dethiophosphorylation (0.04 s?1 vs. 0.5 s?1) and K+-stimulated dethiophosphorylation (0.54 s?1 vs. 230 s?1) are much lower than those for the corresponding reactions based on ATP. (6) In contrast to the phosphoenzyme, the thiophosphoenzyme is ADP-sensitive (with an apparent rate constant in ADP-induced dethiophosphorylation of 0.35 s?1, ) and is relatively K+-insensitve. The for K+ in dethiophosphorylation is 0.9 mM and in dephosphorylation 0.09 mM. The thiophosphoenzyme appears to be for 75–90% in the ADP-sensitive E1-conformation. 相似文献