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91.
Benign and malignant hepatocellular tumors: evaluation of tumoral enhancement after mangafodipir trisodium injection on MR imaging 总被引:2,自引:0,他引:2
Coffin CM Diche T Mahfouz A Alexandre M Caseiro-Alves F Rahmouni A Vasile N Mathieu D 《European radiology》1999,9(3):444-449
The aim of this work was to study the ability of mangafodipir trisodium (Mn-DPDP)-enhanced MR imaging in differentiating
malignant from benign hepatocellular tumors. Eleven patients with pathologically proved hepatocellular carcinomas, six with
focal nodular hyperplasias, and one with a single hepatocellular adenoma were examined by spin-echo and gradient-echo T1-weighted
sequences before, 1 h after, and 24 h after intravenous injection of Mn-DPDP (5 μmol/kg). Quantitative analysis including
enhancement and lesion-to-liver contrast-to-noise ratio, and qualitative analysis including the presence of a central area
and a capsule were done on pre- and post-Mn-DPDP-enhanced images. Enhancement was observed in all the tumors with significant
improvement (p < 0.05) in contrast-to-noise ratio 1 h after, and 24 h after intravenous injection of Mn-DPDP. There were no significant
differences in the mean enhancement and the mean contrast-to-noise ratio (CNR) between benign and malignant tumors. No enhancement
was seen within internal areas observed in 7 hepatocellular carcinomas, and in 5 focal nodular hyperplasias, and within capsules
which were observed in 9 hepatocellular carcinomas. In our study, Mn-DPDP increased CNR of both benign and malignant tumors
but did not enable differentiation between benign and malignant tumors of hepatocellular nature.
Received: 7 October 1997; Revision received: 25 February 1998; Accepted: 10 July 1998 相似文献
92.
Morger ID Truttmann AC von Vigier RO Bettinelli A Ramelli GP Bianchetti MG 《Pediatric nephrology (Berlin, Germany)》1999,13(1):50-53
Selective electrodes have been designed for determining plasma ionized magnesium. In kidney disease the relationship between
ionized and total circulating magnesium is often altered. Hence plasma ionized magnesium (ETH 7025 membrane) was determined
in 25 patients with primary renal tubular disorders; 6 patients had total hypomagnesemia. Total plasma magnesium was never
reduced in the remaining 19 patients. Plasma ionized magnesium values were low in the 6 patients with total hypomagnesemia.
In 18 of the 19 patients without total hypomagnesemia plasma ionized magnesium values were not reduced. Ionized hypomagnesemia
was noted in a patient with normal total plasma magnesium in the context of hypercalciuric nephrocalcinosis of unknown origin.
The study demonstrates an excellent concordance between plasma total and ionized magnesium in tubular disorders associated
with total hypomagnesemia and a good concordance in tubular disorders that are not linked with total hypomagnesemia. The determination
of circulating ionized magnesium is of little value in the diagnostic work-up of the vast majority of renal tubular disorders.
The determination might perhaps disclose latent hypomagnesemia in nephrocalcinosis of unknown cause.
Received: 20 March 1998 / Revised: 28 May 1998 / Accepted: 29 May 1998 相似文献
93.
重组人神经营养因子-4/5蛋白抗三氧化二砷神经毒作用 总被引:5,自引:0,他引:5
目的初步观察重组人神经营养因子-4/5(hNT-4/5)蛋白对三氧化二砷毒性的抑制作用。方法利用hNT-4/5蛋白具有抗神经毒性的特点,采用本实验室克隆表达及部分纯化的具有天然hNT-4/5蛋白生物学活性的重组hNT-4/5蛋白,以不同水平的重组hNT4/5蛋白(0-100μl)与不同浓度的As2O3(0-160μmol/L)同时加入各组鸡胚前脑神经细胞和PC12细胞培养液中共同孵育24-48小时,观察其对染毒鸡胚前脑神经细胞存活和PC12细胞突起生长的影响作用。结果在鸡胚前脑神经细胞和PC12细胞中与As2O3共同培养48小时后,对照组与实验组的细胞存活率差异有显著性,而且细胞存活率和突起数目随hNT-4/5浓度增高而提高和增加。结论初步观察到重组hNT4/5蛋白具有抑制As2O3的毒性作用,为从基因工程途径寻找抗环境毒物因子提供了依据。 相似文献
94.
坦克作业条件下驾驶室内挥发性有机物定性分析 总被引:5,自引:2,他引:3
目的:了解某型坦克作业条件下驾驶室内挥发性有机物的污染状况,为制定防治措施提供科学依据。方法:应用气相色谱-质谱联用技术(GC-MS)对某型坦克单纯行进,行进打炮,停车打炮等工作状态下驾驶室内以及废气排放口的挥发性有机物(VOCs)进行了全谱分析,结果:共检出134种污染物质,包括脂肪烃类,单环芳烃类,多环芳烃类以及机酸,碱,酯,醛,酮,杂环化合物等。结论:实验结果表明这些物质主要来源于油类蒸汽, 相似文献
95.
96.
Gennadi V. Glinsky Valeri V. Mossine Janet E. Price Diane Bielenberg Vladislav V. Glinsky Honnavara N. Ananthaswamy Milton S. Feather 《Clinical & experimental metastasis》1996,14(3):253-267
We studied the influence of 10 synthetic glycoamine analogs on colony formation in 0.3 and 0.9% agarose by metastatic human breast carcinoma (MDA-MB-435) and melanoma (TXM-13) cells. Nine synthetic analogs significantly inhibited the colony formation in 0.9% agarose of MDA-MB-435 human breast carcinoma cells; five compounds caused a 73–83% reduction of colony formation. Seven synthetic glycoamines caused a significant inhibition of colony formation in 0.9% agarose by TXM-13 melanoma cells with the inhibitory effect ranging from 71 to 87%. The 50% inhibition (I50) doses and relative activity rank of the compounds were similar for both breast carcinoma and melanoma cell lines. The murine B16 melanoma cell aggregation assay was employed to elucidate the potential mechanism(s) of the inhibitory activity of synthetic glycoamines. The relative activity ranks of the compounds based on the independently determined I50 doses for both cell aggregation and clonogenic growth assays were very similar for the four most active synthetic analogs and clearly indicated the importance of hydrophobic amino acid in mediating the bioactivity of synthetic glycoamines. In both experimental systems (clonogenic growth in agarose and cell aggregation assay) the leading compound was N-(1-deoxy-d-fructos-1-y1)-d-leucine (Fru-d-Leu) and the least active analog was N-(1-deoxy-d-fructos-1-yl)-glycine (Fru-Gly). These results show that synthetic glycoamines may act by competing for specific carbohydrate-lectin interactions, particularly those involving -galactoside-specific lectins expressed on metastatic cells. 相似文献
97.
The reactivation of human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7) inhibited by O-ethyl-S-2-di-isopropylaminoethyl methylphosphonothioate (VX) and the protection against AChE inhibition by O-1,2,2-trimethylpropyl methylphosphonofluoridate (Soman) was studied with sixteen quaternized pyridinium compounds. TMB-4 which is known as a good reactivator of AChE inhibited by organophosphates proved to be the most effective reactivator. Of the tested newly synthetised compounds 3 were fairly good reactivators of methylethoxyphosphonylated AChE. These compounds have 2 pyridinium rings connected by a dimethylether link and a hydroxiiminomethyl group in position 2 of one pyridinium ring, while the radicals of the other pyridinium ring are benzoylcarbonyl, cyclohexylcarbonyl or amidocarbonyl residue.The rate of reactivation with these compounds followed a two-phase pattern, being fast at the beginning and then slowing down to an equilibrium. Kinetic treatment of the first-phase reaction course yielded the second-order rate constants of reactivation. All 3 compounds had similar reactivating efficiency (k
r values range from 0.8×103 to 3.6×103 M–1 min–1) and in effective concentrations (1 to 100 M) they also inhibited AChE (K
i(app) values range from 0.11 to 0.19 mM). Their reactivating properties were not better than those revealed by TMB-4 (k
r= 19.4×103 M–1 min–1) which was tested as a reference compound.HGG-12, HGG-42 and HI-6 were also found to exert a good protective effect against AChE inhibition by Soman; no protection was obtained with TMB-4. 相似文献
98.
Reynolds DL Repta AJ Sternson LA 《Journal of pharmaceutical and biomedical analysis》1983,1(3):339-346
The influence of electrolytes on the retention of organic cationic solutes in reversed-phase high-performance liquid chromatography (RP-HPLC) has been investigated. The effects of the nature and concentration of electrolytes and mobile phase pH on the retention of two model quaternary ammonium compounds were studied on mu-Bondapak C18 stationary phase with aqueous methanolic eluents. The nature and concentration of inorganic cations added to the mobile phase modified the retention of the solutes. The counter anion of the added electrolyte did not perceptibly influence solute retention at constant mobile phase pH, although it did significantly influence solute retention when the electrolytes were added to unbuffered mobile phases. The retention data are consistent with the inclusion of an ion exchange contribution to the retention of cationic solutes in the systems investigated. 相似文献
99.
Katharina Wenzel-Seifert Jürgen Ervens Roland Seifert 《Naunyn-Schmiedeberg's archives of pharmacology》1991,344(4):396-402
Summary The chemoattractants, N-formyl-L-methio-nyl-L-leucyl-L-phenylalanine (fMet-Leu-Phe), complement C5a and platelet-activating factor (PAF), induce ß-glucuronidase release and aggregation and an increase in cytosolic Ca2+ [Ca2+]i in human neutrophils. We studied the roles of cAMP and cGMP in neutrophil avtivation, using their cell-permeant analogues, N6,2-O-dibutyryl adenosine 3:5-cyclic monophosphate (Bt2cAMP) and N2 ,2-O-dibutyryl guanosine 3:5-cyclic monophosphate (Bt2cGMP) and the NO-containing compounds, sodium nitroprusside (SNP), 3-morpholino-sydnonimine (SIN-1) and its prodrug, molsidomine (SIN-10). Bt2cAMP, Bt2cGMP, SIN-1 and SIN-10 but not SNP inhibited exocytosis induced by fMet-Leu-Phe. Superoxide dismutase potentiated the inhibitory effect of SIN-1. Bt2cGMP and SNP potentiated C5a-induced ß-glucuronidase release, Bt2cAMP, KCN, SIN-1 and SIN-10 being ineffective. KCN partially reversed the stimulatory effect of SNP, and in the presence of superoxide dismutase, SIN-1 potentiated C5a-induced exocytosis. PAF-induced ß-glucuronidase release was not affected by Bt2cAMP, Bt2cGMP, SNP and SIN-1. Bt2cGMP was more effective than Bt2cAMP to inhibit aggregation and the increase in [Ca2+]i induced by fet-Leu-Phe at submaximally effective concentrations. C5a-induced rises in [Ca2+]i were not affected by Bt2cAMP and Bt2cGMP. Bt2cAMP but not Bt2cGMP inhibited the effect of PAF at submaximally effective concentrations on [Ca2+]i. Our data suggest (I) that Bt2cGMP and Bt2cAMP differentially modulate neutrophil activation, that (II) NO-containing compounds partially mimick the effects of Bt2cGMP on exocytosis and that (III) cGMP plays an inhibitory role in fMet-Leu-Phe- and a stimulatory role in C5a-induced ß-glucuronidase release.
Send offprint requests to R. Seifert at the above address 相似文献
100.
Interactions of halogenated industrial chemicals with transthyretin and effects on thyroid hormone levels in vivo 总被引:2,自引:0,他引:2
Van den Berg K. J. van Raaij J. A. G. M. Bragt P. C. Notten W. R. F. 《Archives of toxicology》1991,65(1):15-19
Previous results in experimental systems have suggested that hydroxylated PCBs may decrease thyroid hormone levels through associative interaction with transthyretin. In the present paper it was investigated whether this property was also shared by various industrial chemicals, mainly pesticides. In total, 65 compounds from 12 chemical groups were analyzed for direct interference with the T4 binding site of transthyretin using a competitive binding assay. Sixty per cent of the compounds were competitive at a concentration level of 100 M. Relatively strong interactions were observed by several chlorophenols, chlorophenoxy acids and nitrophenols, as well as by individual compounds such as hexachlorobenzene, dicofol, bromoxynil and tetrachlorohydroquinone. Examples from these chemical groups, e.g. pentachlorophenol, 2,4-dichlorophenoxybutyric acid, dinoseb and bromoxynil, also reduced plasma TT4 levels in rats. In addition, bromoxynil decreased plasma TT3 levels. The results suggest the existence of a number of halogenated industrial chemicals with a potential for lowering plasma thyroid hormone levels through interference with hormone transport carriers. 相似文献