首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 437 毫秒
1.
Summary A case report of a de novo deletion in the short arm of chromosome 7 is presented (46,XX,del(7)(p21pter)). The five-month-old girl's major symptoms are: trigonocephalus with craniosynostosis, median bony forehead bulge, high palate, atrial septal defect, anal atresia and perineal fistula, thumb insertion far to ulnar-proximal, and a slightly retarded psychomotor development. The other cases with monosomy 7p described in the literature are reviewed.  相似文献   

2.
7-Oxo, 7α-hydroxy- and 7β-hydroxysterols (campesterol, stigmasterol and sitosterol derivatives) were isolated from the roots of Euphorbia fischeriana, a drug used for its antitumour properties in traditional Chinese medicine. Some of these steroids show antitumour activity and might be related to the presumed activity of the drug.  相似文献   

3.

Erratum

Mammalian genome, volume 5, number 7, 1994, pp 416–423  相似文献   

4.
赤霉素A4,A7的研究进展   总被引:7,自引:0,他引:7  
赤霉素A_4、A_7的研究进展颜方贵,秦杰,何增国,李季伦(北京农业大学生物学院,北京100094)赤霉素A_3(GA_3)是目前应用最广的植物生长激素之一。随着研究的深入,对该族的其它同系物,特别是GA_4、GA_7越来越受到重视,这是由于GA_4...  相似文献   

5.
The metabolic fate of the bile add analogs, 3α,7α-dihydroxy-7β-methyl-5β-cholanoic acid and 3α,7β-dihydroxy-7α-methyl-5β-cholanoic acid, was investigated and compared with that of chenodeoxycholic acid in hamsters. Both bile acid analogs were absorbed rapidly from the intestine and excreted into bile at similar to that of chenodeoxycholic acid. In the strain of hamster studied, the biliary bile were conjugated with both glycine and taurine. After continuous intravenous infusion, chenodeoxycholic acid the analogs became the major bile acid constituents in bile. After oral administration of a single dose of these compounds, fecal analysis revealed the existence of unchanged material (25–35%) as well as considerable amounts of metabolites (65–75%). The major metabolites excreted into feces were more polar than the starting material and were tentatively identified as trifaydroxy-7-methyl compounds by radioactive thin-layer chromatography. However, monohydroxy compounds were also found in the fecal extracts. These results show that chenodeoxycholic acid and ursodeoxycholic acid with a methyl group at the 7-position are resistant to bacterial 7-dehydroxylation than the normally occurring bile acids and that a certain proportion of these analogs is hydroxylated to give the corespondiag trihydroxy compound(s), In a control experiment, about 5% of administered chenodeoxychoulic acid was metabolized to a trihydroxy feile acid, but most of the compound (95%) was transformed into lithocholic acid.  相似文献   

6.
本种直脚蚊采自云南勐腊(1976年8月)。这是我国发现的第三种直脚蚊。它和已知的其他两种,即anopheloides(Giles,1903)(类按直脚蚊)与lanyuensis Lien,1968(兰屿直脚蚊),都属花白直脚蚊组(albipes group)。成蚊与我国分布最广的anopheloides很近似,两者都无翅前鬃,亚气门鳞簇不分叉,但本种的触须有3个白斑,后附节Ⅱ的白环远比末端的为宽,而anopheloides的触须仅有2个白斑,后  相似文献   

7.
Among oxysterols oxidized at C7 (7α-, 7β-hydroxycholesterol, and 7-ketocholesterol), 7β-hydroxycholesterol and 7-ketocholesterol involved in the cytotoxicity of oxidized low density lipoproteins (LDL) are potent inducers of apoptosis. Here, we asked whether all oxysterols oxidized at C7 were able to trigger apoptosis, to stimulate interleukin (IL)-1β and/or tumor necrosis factor (TNF)-α secretion, and to enhance adhesion molecule expression (intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin) on human umbilical venous endothelial cells (HUVECs). Only 7β-hydroxycholesterol and 7-ketocholesterol were potent inducers of apoptosis and of IL-1β secretion. TNF-α secretion was never detected. Depending on the oxysterol considered, various levels of ICAM-1, VCAM-1 and E-selectin expression were observed. So, oxysterols oxidized at C7 differently injure and activate HUVECs, and the α- or β-hydroxyl radical position plays a key role in apoptosis and IL-1β secretion.  相似文献   

8.
The reduction of 3-ethylenedioxy-7-oximino-5-androsten-17β-yl acetate and of its 17β-tetrahydropyranyl ether analog with sodium in ethanol, followed by thin-layer chromatography, allowed the isolation of the corresponding 17β-hydroxy- and 17β-tetrahydropyranyioxy-5-en-7β- and 7α-amines which were also characte-rized as 7-acetamides. The acylation of the two epimeric 17β-hydroxy-5-en-7-amines with succinic anhydride followed by selective saponification of the 17β-hemisuccinate group and diazomethane esterification, gave the corresponding 17β-hydroxy-5-en-7β- and 7α-hemisuccinamido methyl esters characterized also as 17β-acetates. On the other hand, the acylation of the two 17β-tetrahydropyranyl-oxy-5-en-7-amines with the acid chloride of terephthalic acid monomethyi ester led to the more rigid 7β- and 7α-terephthalamido methyl ester side-chains. The acidolysis of the 3-ethyleneketal protecting group of the preceding 5-en-7-N-acyl derivatives regenerated the 4-en-3-oxo function while the 17β-tetrahydropyranyl ether group was cleaved simultaneously into the 17β-alcohol. The four desired 7β- and 7α-hemisuccinamido- and terephthalamido carboxylic side-chain derivatives of 17β-hydroxy-4-androsten-3-one (testosterone) were finally obtained by saponification of the corresponding methyl esters.  相似文献   

9.
The naturally occurring tRNA nucleoside preQ(0), 7-cyano-7-deazaguanosine, which is a central intermediate for other natural occurring 7-deazapurine nucleosides was synthesized via a copper(I)-ion-mediated iodo→carbonitrile exchange. The reaction was performed on the easily accessible 7-iodo-7-deazaguanosine under microwave conditions. The overall reaction yield was 30% starting with the glycosylation reaction of the nucleobase. Corresponding 2'-deoxyribonucleosides were prepared following the same route.  相似文献   

10.

Purpose  

A workshop was convened on life cycle assessment (LCA) applied to pavement. The workshop’s primary goals were to establish common practices for conducting LCAs for pavements. In general, pavement LCA has been implemented without clear guidelines for modeling assumptions and reporting. This shortcoming has led to challenges in interpreting and comparing pavement LCA outcomes.  相似文献   

11.
12.
13.
赤霉素A4,A7的发酵研究   总被引:2,自引:0,他引:2  
颜方贵  何增国 《真菌学报》1995,14(4):302-309
  相似文献   

14.
15.
16.
Recent studies have shown that Toll-like receptor (TLR)- signalling contributes significantly to the inflammatory events of atherosclerosis. As products of cholesterol oxidation (oxysterols) accumulate within atherosclerotic plaque and have been proposed to contribute to inflammatory signalling in the diseased artery, we investigated the potential of 7-ketocholesterol (7-KC), 7β-hydroxycholesterol (7β-HC) and 25-hydroxycholesterol (25-HC) to stimulate inflammatory signalling via the lipid-recognising TLRs 1, 2, 4 and 6. Each oxysterol stimulated secretion of the inflammatory chemokine interleukin-8 (IL-8), but not IκBα degradation or tumour necrosis factor-α release from monocytic THP-1 cells. Transfection of TLR-deficient HEK-293 cells with TLRs 1, 2, 4 or 6 did not increase sensitivity to the tested oxysterols. Moreover, blockade of TLR2 or TLR4 with specific inhibitors did not reduce 25-hydroxycholesterol (25-HC) induced IL-8 release from THP-1 cells. We conclude that although the oxysterols examined in this study may contribute to increased expression of certain inflammatory genes, this occurs by mechanisms independent of TLR signalling.  相似文献   

17.
Incubation of ent-7α,18-dihydroxykaur-16-ene with Gibberella fujikuroi affords ent-7α,18,19-trihydroxykaur-16-ene and ent-7α,18-dihydroxykaur-16-en-19-oic acid. There was no transformation into 7,18-dihydroxykaurenolide.  相似文献   

18.
19.
20.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号