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61.
In order to further understand the coordination chemistry of diazamesocyclic systems, a series of mononuclear NiII complexes with 1,4-diazacycloheptane (DACH) functionalized by additional imidazole or pyridine donor pendants, including [NiL1](ClO4)2 · H2O (1), [NiL1Cl](ClO4) (2), [NiL2Cl](ClO4) · CH3OH (3), [NiL2Cl][NiL2](ClO4)3 (4) and [NiL3](ClO4)2 (5), where L1 = 1,4-bis(N-1-methylimidazol-2-yl-methyl)-1,4-diazacycloheptane, L2 = 1,4-bis(pyridyl-2-yl-methyl)-1,4-diazacycloheptane, and L3 = 1,4-bis-(imidazol-4-yl-methyl)-1,4-diazacycloheptane, have been prepared and characterized. A detailed study on the solid structures and solution spectra of these complexes indicates that tetradentate ligands L1, L2 and L3 would lead to new NiII complexes with different coordination environments in the solid states and solution. The N-methyl substituted imidazole functionalized ligand L1 forms green compound 2 and yellow product 1; while the pyridine functionalized ligand L2 affords red product 4 and green complex 3; the ligand L3 results in only one stable mononuclear NiII product 5. The solution behaviors of these interesting compounds were also investigated by UV-Vis technique. 相似文献
62.
Sui HS Liu Y Miao DQ Yuan JH Qiao TW Luo MJ Tan JH 《Molecular reproduction and development》2005,71(2):227-236
Configuration of germinal vesicle (GV) chromatin has been studied and found correlated with the developmental competence of oocytes in several mammalian species. A common feature in the configuration of GV chromatin in the species studied so far is that the diffuse chromatin (the so called "NSN" pattern) condenses into a perinucleolar ring (the so called "SN" configuration) with follicular growth. However, no study has been published on the configuration of GV chromatin in the goat. Nor is it known whether the perinucleolar ring of condensed chromatin (CC) in an oocyte represents a step toward final maturation or atresia. Changes in configurations of GV chromatin and RNA synthesis during goat oocyte growth, atresia and maturation in vivo and in vitro were investigated in this study. Based on both the size of nucleoli and the degree of chromatin condensation, the GV chromatin of goat oocytes was classified into GV1 characterized by large nucleoli and diffuse chromatin, GV2 with medium-sized nucleoli and condensed net-like (GV2n) or clumped (GV2c) chromatin, GV3 with small nucleoli and net-like (GV3n) or clumped (GV3c) chromatin, and GV4 with no nucleolus but clumped chromatin. The results showed that (i) the configurations of GV chromatin in the goat differ from those of other species in that the chromatin did not condense into a perinucleolar ring; (ii) most of the goat oocytes are synchronized at the GV3n configuration before GVBD; (iii) the GVn pattern might represent a healthy state, but the GVc an atretic state; (iv) in both goats and mice, the GC-specific (Chromomycin A3, CMA3) and the AT-specific (Hoechst 33342) fluorochromes followed the same pattern of distribution in GV chromatin; (v) the nucleolar size decreased significantly with oocyte growth and maturation in vivo and in vitro; and (vi) goat oocytes began GVBD at 8 hr and had completed it by 20 hr after onset of estrus. The peculiar configuration of GV chromatin of goat oocytes can be a useful model for studies of morphological and functional changes of different nuclear compartments during the cell cycle and cell differentiation, and the functional differentiation between GV3n and GV3c might be used for reference to the question whether the "SN" configuration in other species inclines toward ovulation or atresia. 相似文献
63.
人新基因hbrp的染色体定位及其对TPK活性的抑制作用(简报) 总被引:1,自引:0,他引:1
hbrp(Human BSP-Related Protein)是我们实验室最近在睾丸组织中克隆的一个人与BSP(bovine seminal plasma)蛋白相关的新基因。为了将有关该新基因信息与现有人类基因组转录图相整合,我们应用荧光原位杂交(fluorescent in situ hybridizationFISH)法进行了该基因的人染色体基因定位,结果成功地将hbrp基因定位在人19号染色体长臂1区3带上。hbrp基因是在对BSP蛋白功能的研究过程中发现并克隆的,其同源性分析发现,与其序列最相近 相似文献
64.
最近的研究表明,蛋白质内含子(intein)介导的B区缺失型凝血因子Ⅷ (BDD-FⅧ)的轻链和重链剪接可顺式促进后者的分泌,而且剪接反应在细胞内、外均可发生.为进一步提高基于蛋白质内含子的双载体转BDD-FⅧ基因的功效,将具有促进重链分泌作用的位于Pro1640~Ser1690的酸性区3(acidic region-3,AR-3)引入重链,检验对蛋白质内含子剪接的BDD-FⅧ蛋白分泌和活性的影响.用融合蛋白内含子的附加ar-3重链(HCAR3IntN)基因和轻链(IntCLC)基因共转染培养的HEK293细胞,分别用ELISA和Coatest法定量分析分泌至培养上清中剪接BDD-FⅧ蛋白量和生物活性,并用免疫印迹观察了细胞内的BDD-FⅧ剪接.结果显示,共转HCAR3IntN和IntCLC基因细胞,分泌至上清的剪接BDD-FⅧ蛋白量和活性分别为(173±26) μg/L和(1.31±0.15) U/ml,明显高于未添加ar-3的蛋白质内含子融合重链(HCIntN)与轻链(IntCLC)基因共转染细胞[(102±12) μg/L和(0.79±0.09) U/ml],提示AR-3对蛋白质内含子剪接的BDD-FⅧ蛋白分泌和活性有明显改善作用.而且,分别转HCAR3IntN和IntCLC基因细胞混合培养后的上清中,亦检测到剪接的BDD-FⅧ蛋白和活性[(35±7) μg/L和(0.28±0.08) U/ml],表明蛋白质内含子可进行不依赖细胞机制的蛋白质剪接.另外,转基因细胞总蛋白呈现明显的可与FⅧ多克隆抗体进行反应的剪接BDD-FⅧ蛋白条带,直观地反映细胞内BDD-FⅧ的剪接.为动物模体内运用蛋白质反式剪接技术的双腺相关病毒载体(AAV)转BDD-FⅧ基因实验提供了依据. 相似文献
65.
66.
Viktoriya S. Anokhina John D. McAnany Jessica H. Ciesla Thomas A. Hilimire Netty Santoso Hongyu Miao Benjamin L. Miller 《Bioorganic & medicinal chemistry》2019,27(13):2972-2977
Ribosomal frameshifting, a process whereby a translating ribosome is diverted from one reading frame to another on a contiguous mRNA, is an important regulatory mechanism in biology and an opportunity for therapeutic intervention in several human diseases. In HIV, ribosomal frameshifting controls the ratio of Gag and Gag-Pol, two polyproteins critical to the HIV life cycle. We have previously reported compounds able to selectively bind an RNA stemloop within the Gag-Pol mRNA; these compounds alter the production of Gag-Pol in a manner consistent with increased frameshifting. Importantly, they also display antiretroviral activity in human T-cells. Here, we describe new compounds with significantly reduced molecular weight, but with substantially maintained affinity and anti-HIV activity. These results suggest that development of more “ligand efficient” enhancers of ribosomal frameshifting is an achievable goal. 相似文献
67.
Panda DK Miao D Bolivar I Li J Huo R Hendy GN Goltzman D 《The Journal of biological chemistry》2004,279(16):16754-16766
We employed a genetic approach to determine whether deficiency of 1,25-dihydroxyvitamin D (1,25(OH)2D) and deficiency of the vitamin D receptor (VDR) produce the same alterations in skeletal and calcium homeostasis and whether calcium can subserve the skeletal functions of 1,25(OH)2D and the VDR. Mice with targeted deletion of the 25-hydroxyvitamin D 1alpha-hydroxylase (1alpha(OH)ase-/-) gene, the VDR gene, and both genes were exposed to 1) a high calcium intake, which maintained fertility but left mice hypocalcemic; 2) this intake plus three times weekly injections of 1,25(OH)2D3, which normalized calcium in the 1alpha(OH)ase-/- mice only; or 3) a "rescue" diet, which normalized calcium in all mutants. These regimens induced different phenotypic changes, thereby disclosing selective modulation by calcium and the vitamin D system. Parathyroid gland size and the development of the cartilaginous growth plate were each regulated by calcium and by 1,25(OH)2D3 but independent of the VDR. Parathyroid hormone secretion and mineralization of bone reflected ambient calcium levels rather than the 1,25(OH)2D/VDR system. In contrast, increased calcium absorption and optimal osteoblastogenesis and osteoclastogenesis were modulated by the 1,25(OH)2D/VDR system. These studies indicate that the calcium ion and the 1,25(OH)2D/VDR system exert discrete effects on skeletal and calcium homeostasis, which may occur coordinately or independently. 相似文献
68.
板齿鼠种群数量中长期预测的时间序列模型 总被引:10,自引:1,他引:10
本文利用时间序列方法(三次指数平滑法),并结合季节指数法,建立了板齿鼠种群数量中长期预测(6个月~1年)的时间序列模型,依据1991年11月~1993年12月在广东省博罗县石湾镇里波水管理区对板齿鼠种群数量动态的调查数据,分别预测了1994年和1995年板齿鼠种群数量的发生,预测准确率达到了86.56%。 相似文献
69.
Mutations in HOXD13 underlie syndactyly type V and a novel brachydactyly-syndactyly syndrome 下载免费PDF全文
Zhao X Sun M Zhao J Leyva JA Zhu H Yang W Zeng X Ao Y Liu Q Liu G Lo WH Jabs EW Amzel LM Shan X Zhang X 《American journal of human genetics》2007,80(2):361-371
HOXD13, the homeobox-containing gene located at the most 5' end of the HOXD cluster, plays a critical role in limb development. It has been shown that mutations in human HOXD13 can give rise to limb malformations, with variable expressivity and a wide spectrum of clinical manifestations. Polyalanine expansions in HOXD13 cause synpolydactyly, whereas amino acid substitutions in the homeodomain are associated with brachydactyly types D and E. We describe two large Han Chinese families with different limb malformations, one with syndactyly type V and the other with limb features overlapping brachydactyly types A4, D, and E and mild syndactyly of toes 2 and 3. Two-point linkage analysis showed LOD scores >3 (theta =0) for markers within and/or flanking the HOXD13 locus in both families. In the family with syndactyly type V, we identified a missense mutation in the HOXD13 homeodomain, c.950A-->G (p.Q317R), which leads to substitution of the highly conserved glutamine that is important for DNA-binding specificity and affinity. In the family with complex brachydactyly and syndactyly, we detected a deletion of 21 bp in the imperfect GCN (where N denotes A, C, G, or T) triplet-containing exon 1 of HOXD13, which results in a polyalanine contraction of seven residues. Moreover, we found that the mutant HOXD13 with the p.Q317R substitution was unable to transactivate the human EPHA7 promoter. Molecular modeling data supported these experimental results. The calculated interactions energies were in agreement with the measured changes of the activity. Our data established the link between HOXD13 and two additional limb phenotypes--syndactyly type V and brachydactyly type A4--and demonstrated that a polyalanine contraction in HOXD13, most likely, led to other digital anomalies but not to synpolydactyly. We suggest the term "HOXD13 limb morphopathies" for the spectrum of limb disorders caused by HOXD13 mutations. 相似文献
70.
目的:探讨胃血管球瘤的病理学特点及临床表现。方法:对1例胃血管球瘤进行组织学表现、免疫组化染色观察及文献复习。结果:组织学特点:肿瘤细胞围绕薄壁血管呈实性排列,大小一致,圆形或多角形,胞质丰富红染或透亮,界限清楚。免疫组化特点:肿瘤细胞表达SMA(++)、Vimentin(+++)。结论:胃血管球瘤是胃一种少见的肿瘤,易误诊为胃肠间质瘤、平滑肌瘤及类癌,可以通过免疫组化染色及形态学观察进行鉴别诊断。 相似文献