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201.
The synthesis and structural characterization of four new copper compounds with formula [Cu(crot)2(isn)2(Hcrot)·H2O] (1), [Cu(oda)(isn)2] (2), [Cu(crot)2(nia)2·(H2O)] (3) and [Cu(oda)(nia)] (4) (crot = trans-2-butenoate, oda = oxydiacetate, isn = isonicotinamide, nia = nicotinamide) is reported. The complexes extend into 3D supramolecular structures by means of hydrogen bonds. EPR spectra of powder samples of the compounds are reported. 相似文献
202.
Methionine Exposure Alters Glutamate Uptake and Adenine Nucleotide Hydrolysis in the Zebrafish Brain
203.
Analysis of the apoC-II gene in apoC-II deficient patients 总被引:7,自引:0,他引:7
S S Fojo S W Law D L Sprecher R E Gregg G Baggio H B Brewer 《Biochemical and biophysical research communications》1984,124(1):308-313
Apolipoprotein C-II (apoC-II), a 79 amino acid protein, is a cofactor for lipoprotein lipase, the enzyme which catalyzes the lipolysis of triglycerides on plasma chylomicrons and VLDL. Patients with apoC-II deficiency have marked elevations in plasma triglycerides, chylomicrons, VLDL, and a type I hyperlipoproteinemia. In order to evaluate the molecular defect in apoC-II deficiency, genomic DNA was analyzed using Southern Blot from 2 independent apoC-II deficient patients and compared to normal controls. Restriction digests of genomic DNA were performed with five different enzymes and the restriction fragments analyzed utilizing a 354 base pair nick-translated apoC-II probe for hybridization following Southern blotting. The restriction fragments varied from 0.8 to 21 Kb, and the pattern with normal DNA was identical to that of the two apoC-II deficient patients. The present study reveals that the apoC-II gene is present in patients with apoC-II deficiency. In addition, no insertional or deletional polymorphism was detected in the apoC-II gene of apoC-II deficient patients. 相似文献
204.
Modifications of plasma lipoproteins after lipase activation in patients with chylomicronemia 总被引:1,自引:0,他引:1
Lipoprotein lipase (LPL) and hepatic lipase (HL) are enzymatic activities involved in lipoprotein metabolism. The purpose of this study was to analyze the physicochemical modifications of plasma lipoproteins produced by LPL activation in two patients with apoC-II deficiency syndrome and by HL activation in two patients with LPL deficiency. LPL activation was achieved by the infusion of normal plasma containing apoC-II and HL was released by the injection of heparin. Lipoproteins were analyzed by ultracentrifugation in a zonal rotor under rate flotation conditions before and after lipase activation. The LPL activation resulted in: a reduction of plasma triglycerides; a reduction of fast-floating very low density lipoprotein (VLDL) concentration; an increase of intermediate density lipoprotein (IDL), which maintained unaltered flotation properties; an increase of low density lipoproteins (LDL) accompanied by modifications of their flotation rates and composition; no significant variations of high density lipoprotein (HDL) levels; and an increase of the HDL flotation rate. The HL activation resulted in: a slight reduction of plasma triglycerides; a reduction of the relative triglyceride content of slow-floating VLDL, IDL, LDL2, and HDL3 accompanied by an increase of phospholipid in VLDL and by an increase of cholesteryl ester in IDL; and a reduction of the HDL flotation rate. These experiments in chylomicronemic patients provide in vivo evidence that LPL and HL are responsible for plasma triglyceride hydrolysis of different lipoproteins, and that LPL is particularly involved in determining the levels and physicochemical properties of LDL. Moreover, in these patients, the LPL activation does not directly change the HDL levels, and LPL or HL does not produce a step-wise conversion of HDL3 to HDL2 (or vice versa) but rather modifies the flotation rates of all the HDL molecules present in plasma. 相似文献
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Abstract The chemical compositions of a number of halophytes from salt marshes on Ynys Môn (Anglesey), Wales, and of some related mesophytes and sand dune plants have been determined. Analyses of the inorganic ions broadly confirmed the existence of a characteristic chemical composition of many monoco-tyledonous salt-marsh plants in that they contain high levels of potassium and relatively low levels of sodium. In contrast to most dicotyledonous halophytes, especially members of the Chenopodiacease, the monocots restrict the entry of inorganic ions and use high levels of soluble sugars to maintain an adequate solute potential. Low calcium levels were not found to be a feature of these plants, as was previously reported. The large amounts of sugars found in the monocotyle-donous plants suggested that they must be located mainly in the vacuoles, in contrast to glycinebetaine which is thought to accumulate principally in the cytoplasm of the salt accumulating Chenopodiaceae. The monocotyledonous halophytes which accumulate proline differ from the normal monocotyledonous physiotype in the accumulation of larger quantities of sodium. Triglochin maritima is one species of this type, and Puccinellia maritima a less extreme example. Spartina spp. accumulating glycinebetaine and β-dimethyl-sulphoniopropionate also have unusually high inorganic ion contents for monocots. Several salt marsh plants contained large quantities of amino acids other than proline. As with ionic composition, the nature of the organic solutes broadly followed taxonomic lines. The usefulness of the physiotype concept is discussed. 相似文献
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Thales R. Cipriani Caroline G. Mellinger Lauro M. de Souza Cristiane H. Baggio Cristina S. Freitas Maria C.A. Marques Philip A.J. Gorin Guilherme L. Sassaki Marcello Iacomini 《Carbohydrate polymers》2008,74(2):274-278
Xylans are the main hemicelluloses found in higher plants, and are often present in phytotherapic medicines. An acidic heteroxylan was obtained from Maytenus ilicifolia leaves by hot 10% aqueous KOH extraction. This was subjected to freeze-thawing process, giving insoluble and soluble fractions and the latter treated with Fehling solution. Its insoluble fraction (MI-HX) was further examined. The acidic heteroxylan gave xylose, galactose, glucose, and 4-O-methylglucuronic acid in a 76:6:9:9 molar ratio and methylation analyses and 13C NMR spectroscopy showed its main chain consists of 4-O-linked β-d-Xylp units. This polysaccharide and another acidic heteroxylan from Phyllanthus niruri had anti-ulcer activity and were able to reduce gastric lesions induced by ethanol by 65% and 78%, with ED50 = 40.0 and 20.4 mg/kg, each respectively. These results suggest that this class of polysaccharide has a protective anti-ulcer effect, and that there is a relation between its chemical structure and biological function. 相似文献