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排序方式: 共有1153条查询结果,搜索用时 15 毫秒
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Fabrizio Villani Milena Galimberti Elena Monti Francesco Piccinini Enrica Lanza Annalinda Rozza Luigia Favalli Paola Poggi Franco Zunino 《Free radical research》1990,11(1):145-151
The effects of two sulfhydryl compounds, glutathione (GSH) and N-acetylcysteine (NAC), on the cardiotoxicity of doxorubicin (DXR) were tested on in vitro and in vivo models. DXR was administered to rats as 4 weekly i.v. doses of 3mg/kg. GSH (1.5 mmoles/kg), given i.v. 10 min before and 1 hr after DXR, was found to prevent the development of the delayed cardiotoxic effects of DXR, as assessed by electrocardiographic and mechanical parameters, as well as by histological examination of left ventricular preparations. In contrast, equimolar oral doses of NAC (1 hr before and 2hrs after DXR) were found to be ineffective. Both GSH and NAC prevented the negative inotropic effect produced by DXR on isolated rat atria. A good correlation exists between the cardioprotective effects of the two agents and their ability to enhance the non-protein sulfhydryl group content of the myocardium. Differences observed in vivo between GSH and NAC might be accounted for by pharmacokinetic factors. 相似文献
4.
Lino Piccinini Paola Borella Annalisa Bargellini Cristina Incerti Medici Alessandra Zoboli 《Biological trace element research》1996,51(1):23-30
The purpose of our study was to investigate the relationship between plasma and hair levels of Se, Zn, and Cu, and cancer.
We selected a total of 66 patients affected by either breast (38) or lung (28) cancer. They entered into the study at the
onset of disease, and before any chemical or radiotherapy. Controls were randomly selected among healthy people and were matched
for sex, age, smoking habits, and residence. In the group of breast cancer, a significant decrease in hair Se was found compared
to controls (p<0.01), whereas plasma Se was only slightly decreased. No difference between cases and controls was detected in both hair
and plasma levels of Zn and Cu. Subjects who developed lung cancer were significantly lower in hair Zn (p<0.05) and Cu (p<0.01) than controls, whereas there was no difference with regard to Se. In addition, plasma Cu of these patients was increased
as compared to controls. 相似文献
5.
M. Palumbo M. Mabilia A. Pozzan G. Capranico S. Tinelli F. Zunino 《Journal of molecular recognition : JMR》1994,7(3):227-231
The sequence specificity of topoisomerase-II-mediated DNA cleavage, stimulated by 2-methyl-9-hydroxy ellipticinium and 4′, 5′,7-trihydroyflavone (genistein) was investigated by sequencing analysis of DNA cleavage sites and molecular modeling techniques. The former drug exhibits a marked preference for a T base at the position immediately preceding the cleavage site (?1). The latter shares the preference for the same base, with an additional preference for a thymine at position +1. The cleavage intensity patterns for the two drugs differ considerably. From a conformational point of view, ellipticinium and genistein exhibit similar overall shape and dimensions. However, the fused ring system in the former generates a planar structure whereas the single bond, connecting the two aromatic portions in the latter, allows internal rotation. The most stable conformation of genistein corresponds to a deviation of about 40° from planarity. A computer-assisted analysis was carried out to compare the steric and electrostatic properties of the two compounds. Two types of preferred (energetically almost degenerate) alignment for the two molecules were found. One corresponds to overlapping of the 9-hydroxyl containing ring of ellipticinium with the 4′-hydroxyphenyl moiety of genistein, the other envisages the same moiety of ellipticine superimposed to the hydroxyl-benzopyrone portion of genistein. The structural similarities of the test drugs might account for the common preference for stimulation of DNA cleavage at position +1, whereas the different possible arrangements of genistein in the cleavable complex could explain both the additional +1 specificity exhibited by this compound and the differences in cleavage intensity patterns observed in comparison to ellipticinium. 相似文献
6.
Annalisa Pezzolo Giorgio Gimelli Amnon Cohen Antonella Lavaggetto Cesare Romano Giuseppina Fogu Orsetta Zuffardi 《Human genetics》1993,92(1):23-27
In situ hybridization of a telomeric (TTA-GGG)
n
sequence to metaphases from three cases of ring chromosome, involving respectively chromosomes 4, 16, and 20, showed the presence of the cognate sequences in all three rings. To investigate whether these ring chromosomes originated by telomere-telomere fusion, we determined, by in situ hybridization, whether telomere-associated sequences and/or specific distal sequences were still present in the ring chromosomes. The finding that these sequences were preserved in all the ring chromosomes strongly indicates that they originated by telomere-telomere fusion. All three subjects carrying the ring chromosomes are affected by the so-called ring syndrome, with failure to thrive, minor dysmorphic signs and no major anomalies. The r(4) patient has the ring in mosaic form with a normal cell line and has normal intelligence. The r(16) and the r(20) patients have moderate mental retardation and suffer from seizures. We conclude that the ring syndrome, even in its more severe manifestation, is caused by ring chromosome instability. 相似文献
7.
E. Baldini Osvaldo Facini Fabrizio Nerozzi Federica Rossi Annalisa Rotondi 《Trees - Structure and Function》1997,12(2):73-81
Light partition has been examined and evaluated on five woody species (Olea europaea, Ficus carica, Pittosporum tobira, Hedera helix maculata, Persica vulgaris) in relation to their leaf morpho-histological characteristics, water and chlorophyll contents. Leaf parameters and optical
properties (reflectance, transmittance, absorbance) in PAR, FR and NIR wavebands (400–1100 nm) were preliminarily submitted
to a canonical correlation analysis where lamina thickness and water content showed a leading role in determining all the
optical properties, while chlorophyll, influential in the PAR region, was remarkably effective only in an extreme pigment
situation when green and albino patches of ivy leaves were compared. Transmittance appeared inversely related to lamina thickness
in accordance with the Lambert Beer law. Significant correlations were found also between mesophyll water content and both
transmittance (positive) and reflectance (negative). Olive leaves showed peculiar optical patterns because of the dense and
continuous trichome layer on their abaxial surface.
Received: 3 January 1997 / Accepted: 5 May 1997 相似文献
8.
Annalisa Botta Elizabeth A. Lindsay Vesna Jurecic Antonio Baldini 《Mammalian genome》1997,8(12):890-895
We have constructed a comparative map in mouse of the critical region of human 22q11 deleted in DiGeorge (DGS) and Velocardiofacial
(VCFS) syndromes. The map includes 11 genes potentially haploinsufficient in these deletion syndromes. We have localized all
the conserved genes to mouse Chromosome (Chr) 16, bands B1-B3. The determination of gene order shows the presence of two regions
(distal and proximal), containing two groups of conserved genes. The gene order in the two regions is not completely conserved;
only in the proximal group is the gene order identical to human. In the distal group the gene order is inverted. These two
regions are separated by a DNA segment containing at least one gene which, in the human DGS region, is the most proximal of
the known deleted genes. In addition, the gene order within the distal group of genes is inverted relative to the human gene
order. Furthermore, a clathrin heavy chain-like gene was not found in the mouse genome by DNA hybridization, indicating that
there is an inconsistent level of gene conservation in the region. These and other independent data obtained in our laboratory
clearly show a complex evolutionary history of the DGS-VCFS region. Our data provide a framework for the development of a
mouse model for the 22q11 deletion with chromosome engineering technologies.
Received: 8 July 1997 / Accepted 11 August 1997 相似文献
9.
Changes in DNA binding ability of daunomycin following structural modifications in the aglycone moiety have been studied by the fluorescence quenching method and by thermal denaturation of the complex. Removal of the methoxyl group at position 4 leads to a slightly stronger binding. Changes in the position of the glycosidic linkage result in a markedly weaker binding. Removal of the hydroxyl group at position 9, with the concomitant formation of a 9,10-anhydro derivative, decreases the binding ability. Methylation of hydroxyl groups at C-6 and C-11 leads to an inactive derivative and makes the binding affinity disappear almost completely. Structure-activity correlations for the DNA binding reaction deduced from these studies are in agreement with earlier findings that relate to the biological activity and confirm the general picture of the binding mechanism. 相似文献
10.
Nuclear protein synthesis has been studied in regenerating rat hepatocytes after partial hepatectomy and α-amanitin treatment. The toxin induced a marked and precocious inhibition of histone synthesis without affecting the acidic nuclear proteins. This inhibition preceded the inhibition of DNA synthesis. The modification of polyribosome profile and of [14C]lysine incorporation on synthesized polypeptides were consistent with a reduction of specific mRNAs. 相似文献