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991.
Annexin A7(膜联蛋白A7)能促进膜的结合、聚集以及融合,在细胞信号转导过程中发挥重要作用。近年来研究表明,其表达异常与前列腺癌、乳腺癌、转移性黑色素瘤以及多形性胶质细胞瘤的发生发展有关。Annexin A7表达不足促进癌症发生,可能是因为基因组不稳定性通过离散信号通路而累及其他肿瘤抑制基因、DNA修复基因以及与凋亡相关的基因。 相似文献
992.
慢性复合应激对大鼠海马生长休止蛋白7表达的影响 总被引:1,自引:0,他引:1
目的 探讨慢性复合应激对大鼠海马神经元中生长休止蛋白7(Gas7)的表达变化及意义.方法 36只大鼠随机分为慢性复合应激组和正常对照组.复合应激组动物进行6周的垂直旋转、睡眠剥夺、捆绑(6h/d)和夜间光照等慢性复合性应激试验;实验结束后,所有动物采用免疫组织化学和免疫印迹等方法 检测大鼠海马Gas7蛋白表达的变化和神经元凋亡情况.结果 Gas7在对照组和实验组大鼠海马各区均有表达,主要表达在海马神经元的胞质和突起内.其中在CA1区和齿状回呈较强阳性表达,CA3区表达则较弱;慢性复合应激组CA1区和齿状回阳性染色加深,平均吸光度明显上升(P<0.05),而CA3区则不明显(P>0.05).慢性复合应激组中部分切片在下托可见少量Caspase-3免疫反应阳性细胞.免疫印迹检测表明,慢性复合应激组大鼠海马Gas7表达明显增强,与正常对照组相比,差异具有显著性(P<0.05).结论 Gas7可能参与了在应激情况对神经元的保护作用,以及促进神经元的发生和发育. 相似文献
993.
994.
Familial hypercholesterolaemia (FH) is a common inherited disorder, associated with premature vascular disease. FH may be caused by many different mutations in the low density lipoprotein receptor (LDLR) gene, about 700 mutations have been described, most of which occur rarely and often only in single families. Although particular mutations are prevalent in certain ethnic groups, countries with heterogeneous population bases (such as NZ) may carry a wide variety of mutations; making a gene screening approach the appropriate first step for a mutation detection programme. We have compared SSCP with DHPLC to assess their effectiveness as methods for LDLR mutation detection. Although five novel LDLR mutations were detected by SSCP in patients with FH, DHPLC was more sensitive, with eight novel mutations detected. Six of these mutations (T392M, R419G, Y421N, 1206-1207delCT, 1872delC, and 1943delC) were clustered in exons 9 and 13 of the EGF precursor homology domain, one (679-680delAC) in the ligand binding domain (exon 4) and the eighth (P774H) in the membrane-spanning domain (exon 16). Twenty five mutations were identified in 35 patients in total. Of these, we were able to detect only 64% of mutations by SSCP even though all variants were detected by DHPLC. All patients are heterozygous for the mutations, which is consistent with the clinical phenotypes. 相似文献
995.
Comparison of different metrics, using three large samples of haplotypes from different populations, demonstrates that rho is the most efficient measure of association between pairs of single nucleotide polymorphisms (SNPs). Pairwise data can be modeled, using composite likelihood, to describe the decline in linkage disequilibrium with distance (the Malecot model). The evidence from more isolated populations (Finland, Sardinia) suggests that linkage disequilibrium extends to 427-893 kb but, even in samples representative of large heterogeneous populations, such as CEPH, the extent is 385 kb or greater. This suggests that isolated populations are not essential for linkage disequilibrium mapping of common diseases with SNPs. The in parameter of the Malecot model (recombination and time), evaluated at each SNP, indicates regions of the genome with extensive and less extensive disequilibrium (low and high values of in respectively). When plotted against the physical map, the regions with extensive and less extensive linkage disequilibrium may correspond to recombination cold and hot spots. This is discussed in relation to the Xq25 cytogenetic band and the HFE gene region. 相似文献
996.
Seung Yong Park Hisashi Arase Keisuke Wakizaka Nakami Hirayama Shigehiro Masaki So-Ichiro Sato Jeffrey V. Ravetch Takashi Saito 《European journal of immunology》1995,25(7):2107-2110
The function of the Fc receptors γ chain (FcRγ) for the expression of the T cell receptor (TCR) complex and for T cell development, especially for T cells localized in epithelia, was investigated by analyzing FcRγ-deficient mice. In wildtype mice, CD8αα+β?TCRαβ+ T cells of intestinal intraepithelial lymphocytes (i-IEL) utilized CD3ζ homodimers and ζ-FcRγ heterodimers, whereas CD8α α+β?TCRγδ+ i-IEL used ζ-FcRγ and FcRγ homodimers in the TCR complex. On the other hand, these T cells in FcRγ-deficient mice contained only ζ homodimers. The surface expression of the TCR complex was reduced in CD8αα+β?i-IEL and dendritic epidermal T cells (DETC) in these mice, whereas the development of these T cells was normal. The degree of reduction appeared to depend on the expression level of FcRγ. In contrast to these populations, TCRγδ+ intraepithelial T cells in reproductive organs (r-IEL) were dramatically decreased, suggesting that the development of r-IEL is FcRγ-dependent, probably due to the predominant usage of FcRγ homodimers in the TCR complex. These results indicate that the FcRγ chain contributes differently to the TCR expression and to the development of T cells localized in epithelia. 相似文献
997.
NIH3T3 cells transfected with an activated Ha-ras oncogene were treated with L-PHA, the leukoagglutinin from red kidney beans. Cell lines resistant to L-PHA-mediated cytotoxicity were isolated and found to contain reduced levels of L-PHA-binding oligosaccharides. The levels of N-acetylglucosaminyltransferase V, the enzyme responsible for the initiation of the1–6 branch, were reduced in L-PHA-resistant cells. Tumorigenicity in nude mice was unchanged by the change in oligosaccharide expression, but the ability to form lung tumors after intravenous injection was significantly reduced. These results demonstrate that the ability of NIH3T3 cells transfected with an activated Ha-ras oncogene to form lung tumors after intravenous injection into nude mice is reduced in all six L-PHA selected cell lines containing a reduction in1–6 branched Asn-linked oligosaccharides. 相似文献
998.
Abdul A. Hassoni Peter T. A. Gray 《Pflügers Archiv : European journal of physiology》1994,428(3-4):269-274
The control of Cl– conductance in rat parotid isolated acinar cells was studied by combined use of whole-cell recording and flash photolysis techniques. Cells were voltage-clamped either at a membrane potential of –40 mV or stepped between –85 mV and 0 mV. Bath-applied carbachol and noradrenaline evoked Cl– current at –85 mV and K+ current at 0 mV. Similar current activations resulted from the photolytic release of either inositol trisphosphate (InsP
3) or Ca2+ by a brief near-UV flash. The peak amplitudes of the Cl– conductance (at –85 mV), measured relative to the K+ conductance (at 0 mV), evoked by application of carbachol, noradrenaline or direct manipulation of cytosolic free calcium ([Ca2+]i), were very similar, being 0.56±0.09 (mean±SEM,n=9), 0.52 ± 0.01 (n=7) and 0.46±0.06 (n=7). In contrast, the relative amplitude of the Cl– conductance evoked by InsP3 was much larger: 1.49±0.24 (n=9). Neither bath application of isoprenaline nor photolysis of caged cAMP induced any detectable membrane current. The most probable interpretation of these results is that the observed activation of Cl– conductance by agonists can be explained by the elevation of [Ca2+]i alone. In addition, the present results provide further support for the previously reported suggestion that the Cl– channels and the Ca2+-release sites are co-localised [10]. 相似文献
999.
H. Ehrenreich C. Kolmar C. Pittius F. -D. Goebel 《Journal of molecular medicine (Berlin, Germany)》1988,66(4):175-180
Summary Administration of synthetic human corticotropin-releasing factor (hCRF, 2 µg/kg body weight) during simultaneous application of the opioid antagonist naloxone (1.6 mg i.v. bolus, followed by an infusion at a rate of 1.2 mg/h) produced a significant increase in plasma C-peptide levels of six male Type 2 diabetic patients which even exceeded the postprandial values. This stimulatory effect of hCRF/naloxone on plasma C-peptide was less pronounced in six healthy men. hCRF alone did not provoke any reaction of plasma C-peptide in either group.The possibility of a paracrine, CRF-dependent mechanism in pancreatic islets which somehow involves inhibitory opioid receptors is preferentially discussed. Such a mechanism may underlie the stimulatory action of hCRF/naloxone on B cells and would explain the absent reaction of peripheral venous plasma C-peptide to hCRF alone as well as the amplifying effect of simultaneous opioid receptor blockade.Abbreviations ACTH
adrenocorticotropic hormone
- C-peptide
connecting-peptide
- CRF
corticotropin-releasing factor
- hCRF
human CRF
- oCRF
ovine CRF
- min
minutes
- S.D.
standard deviation
- S.E.M.
standard error of the mean
This study was supported by the Deutsche Forschungsgemeinschaft (Go 299/3-2)Dedicated to Professor Dr. N. Zöllner on the occasion of his 65th birthday 相似文献
1000.
The biodegradation of different porous β-whitlockite materials are studied by in vivo experiments, radiographie follow-ups and light microscopy observations. The materials were implanted in rabbit tibiae for 16 mnth. Micropores play an important role in the biodegradation rate. The resorbing materials evoke an inflammation with plasma cells. The resorption starts in the medulla, and the phagocytosed particles are removed to the lymph nodes. Normal bone function can be restored after all the implant material is resulted. 相似文献