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排序方式: 共有776条查询结果,搜索用时 156 毫秒
81.
Christophe J Le Coz G Jelen A Goossens M Vigan G Ducombs A Bircher F GiordanoLabadie A PonsGuiraud MilpiedHomsi M Castelain D Tennstedt JL Bourrain G Bernard GERDA France 《Contact dermatitis》2004,50(3):126-127
Introduction: Patients sensitized to para‐phenylenediamine (PPD) have a high degree of patch test reactivity to Disperse Orange 3 (DO3), and a lesser one to Disperse Red 1 and Red 17. Two successive patients positive to PPD, Disperse Red 1 and 17, negative to DO3 were real eye‐openers for our considerations about purity of our current allergen DO3.
Materials and methods: We realized comparative thin‐layer chromatography (TLC), with DO3 from Chemotechnique®(DO3‐Chem) and Trolab®(both extracted from petrolatum), and "pure" DO3 from two chemical providers. TLC clearly indicated that DO3‐Chem was not DO3. HPLC analysis with pure DO3 from Chemotechnique® and comparison of structures by NMR with samples of DO3, revealed that DO3‐Chem was Disperse Orange 31 (DO31). In addition, signals through the GERDA network allowed the collection of test materials and observations. Among other members, only 2 used DO3‐Chem (from 2 different batches) that was DO31 too, according to TLC Results: According to their data, they observed no or a lower reactivity to DO3 than expected (4 patients DO3‐Chem + among 23 PPD+ e.g.). Finally, the error was proved to be due to the provider of the dye to Chemotechnique®, who likely deleted the 1 of Disperse Orange 31 on his packaging.
Discussion: Chemical structure of DO31 indicates a possible in vivo hydrolysis into nitroaniline and a second compound, a substituted PPD derivative that clearly does not frequently react in PPD positive patients. Like drugs, patch tests are submitted to post‐commercialization controls. In addition to allergens providers who should enhance their quality controls, dermato‐allergologists have to be vigilant, and must active networks when they observe a rare bird. 相似文献
Materials and methods: We realized comparative thin‐layer chromatography (TLC), with DO3 from Chemotechnique®(DO3‐Chem) and Trolab®(both extracted from petrolatum), and "pure" DO3 from two chemical providers. TLC clearly indicated that DO3‐Chem was not DO3. HPLC analysis with pure DO3 from Chemotechnique® and comparison of structures by NMR with samples of DO3, revealed that DO3‐Chem was Disperse Orange 31 (DO31). In addition, signals through the GERDA network allowed the collection of test materials and observations. Among other members, only 2 used DO3‐Chem (from 2 different batches) that was DO31 too, according to TLC Results: According to their data, they observed no or a lower reactivity to DO3 than expected (4 patients DO3‐Chem + among 23 PPD+ e.g.). Finally, the error was proved to be due to the provider of the dye to Chemotechnique®, who likely deleted the 1 of Disperse Orange 31 on his packaging.
Discussion: Chemical structure of DO31 indicates a possible in vivo hydrolysis into nitroaniline and a second compound, a substituted PPD derivative that clearly does not frequently react in PPD positive patients. Like drugs, patch tests are submitted to post‐commercialization controls. In addition to allergens providers who should enhance their quality controls, dermato‐allergologists have to be vigilant, and must active networks when they observe a rare bird. 相似文献
82.
D. Guiraud 《Medical & biological engineering & computing》1994,32(6):610-614
The object of this paper is to present a real-time application of an artificial neural network (ANN). The application for
which this network is demonstrated is a motorised orthosis with six degrees-of-freedom for use by a paraplegic; a ‘walking
machine’. Theoretical networks and training methods need modification to function correctly with a real application. Several
complex phenomena that are very diffucult to model have to be accommodated; the starting threshold of the activators, nonlinearity,
noise, and the non-biunivocity between successive system states (position, velocity, actuator controls). The modifications
made to the network and the associated training method partially alleviate these difficulties. 相似文献
83.
Thibaut Liebgott Haihong Li Yuanmu Deng Jay L Zweier 《Magnetic resonance in medicine》2003,50(2):391-399
Proton electron double resonance imaging (PEDRI) is a double resonance technique where proton MRI is performed with irradiation of a paramagnetic solute. A low-field PEDRI system was developed at 20.1 mT suitable for imaging free radicals in biological samples. With a new small dual resonator, PEDRI was applied to image nitroxide free radicals in isolated beating rat hearts. Experiments with phantoms showed maximum image enhancement factors (IEF) of 42 or 28 with TEMPONE radical concentrations of 2-3 mM at EPR irradiation powers of 12W or 6W, respectively. In the latter case, image resolution better than 0.5 mm and radical sensitivity of 5 microM was obtained. For isolated heart studies, EPR irradiation power of 6W provided optimal compromise of modest sample heating with good SNR. Only a small increase in temperature of about 1 degrees C was observed, while cardiac function remained within 10% of control values. With infusion of 3 mM TEMPONE an IEF of 15 was observed enabling 2D or 3D images to be obtained in 27 sec or 4.5 min, respectively. These images visualized the change in radical distribution within the heart during infusion and clearance. Thus, PEDRI enables rapid and high-quality imaging of free radical uptake and clearance in perfused hearts and provides a useful technique for studying cardiac radical metabolism. 相似文献
84.
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86.
The authors present, among 200 intracranial arterial aneurysms, 13 cases where the angiographic diagnosis of the aneurysm had been difficult. Among them, there were ten mistakes through default, and four mistakes through excess. Angiographic studies were done early, about the third day following subarachnoidal hemorrhage, so that conscious patients may have rapid surgery. The main diagnosis defaults were observed in aneurysms of the anterior communicating artery (cases 1, 2, 3, 4, 6), where the flexurae and arterial anomalies explain the diagnostic mistakes; double anterior cerebral artery, median anterior cerebral artery of Lazorthes, early origin of the frontopolar artery or of the callosomarginal artery. The aneurysms of the posterior wall of the carotid bifurcation, were hidden by this artery in the A.P. view and by the middle cerebral artery in the profile view (cases 5 and 7). Oblique views are necessary for the two localizations of these aneurysms. The middle cerebral aneurysms (case 8) may be hidden by a bony superposition. The Ziedses des Plantes subtraction method obviates this diagnostic default. Aneurysms of the peripheral branches of cerebral arteries (case 9) are filled later and slightly. Aneurysms of an artery less than 3 mm wide (posterior communicating artery, lenticular artery) are difficult to discriminate from their enlarged infundibulum (case 10). The small size of the aneurysm is not the only explanation of the difficult diagnosis. Indeed, few aneurysms are not evidenced by the first angiography, done at an early stage, even if any spasms exist. Only repeated angiographies could show the aneurysm particularly in young people. We repeat the angiography 15 to 20 days after the first one, and even some months later. In two young patients, angiographic studies were repeated a few times in three years and were normal; but after four years in one case and five years in the other, a new subarachnoidal hemorrhage occurred, and only then was the aneurysm shown by a new angiography (cases 4 and 5). In our series, the angiographic spasm could not afford an explanation for the diagnostic default. This, soon after the subarachnoidal hemorrhage, might be explained by the hemostatic clot which compresses or plugs the aneurysm. Further, the clot's lysis occurs, and the aneurysm can be evident. A double conlcusion must be drawn: --first, the angiography must be repeated if the image is dubious; the angiographic technique must be perfect and varied (oblique view, subtraction method, enlargement technique). Mistakes through excess, leading to useless operations, are as dangerous as mistakes through default; --secondly, great care should be exerted when reading and interpreting the X-ray films in the post-operative period in order to evaluate the surgical results, as well as in the preoperative period. 相似文献
87.
88.
目的:研制和评价新碘标阿片受体显像剂7αOiodoalyldiprenorphine(7αOIADPN)。方法:选用阿片肽拮抗剂DPN经碘代锡烷标记法成功地获得了一个原始的碘标阿片肽类似物,并对其进行理化性能、药理作用和生物学功能评价。结果:体外和体内阿片受体结合分析表明这一新的阿片配体具有非常高的亲和力(Ki=4×10-4μmol/L)。注药后20min动物脑内的特异性结合占63%,且其在脑内滞留时间较长而有利于成像。阿片抑制试验和抗痛活性研究分别反映碘标7αOIADPN可能对3种阿片受体(μ,δ,κ)都有亲和力,并保持了原有的药理特性和生物学功能。结论:碘标7αOIADPN作为新阿片受体显像剂较适于今后SPECT阿片受体研究。 相似文献
89.
J P Aymard C Janot G Thibaut F Bertrand B Legras P Lederlin F Streiff 《Acta haematologica》1984,71(5):316-321
Several haematological and immunological parameters were studied before and after a 4-week trial of oral levamisole (300 mg/week) in 15 patients with chronic lymphocytic leukaemia. We found no statistically significant difference in the mean peripheral blood counts of total lymphocytes, E-rosette-forming lymphocytes, monocytes, polymorphonuclear neutrophils, eosinophils and platelets. Mean serum levels of IgG, IgA, IgM, IgD, C3 and C4 were not statistically affected by levamisole nor was the mean lymphocyte stimulation modified by various mitogens (phytohaemagglutinin, concanavalin A, pokeweed mitogen, tuberculin, candidin). The mean IgE level was statistically increased (p less than 0.05) after levamisole administration but remained below the normal upper limit. A high rate (46%) of clinical and haematological adverse reactions (1 patient developed thrombocytopenia) was associated with levamisole administration. These results suggest that levamisole, as given in this trial, has no obvious beneficial effect and cannot be recommended in patients with chronic lymphocytic leukaemia. 相似文献
90.
X-ray microanalysis as applied to fungal tissues 总被引:1,自引:0,他引:1
M Thibaut M Ansel J de Azevedo Carneiro 《British journal of experimental pathology》1977,58(2):209-214
Analytical electron microscopy combines the techniques of high-resolution electron microscopy and high-sensitivity X-ray microanalysis of samples. Spectrometry of the elements (characteristic X-rays produced by a scanning electron microprobe) was employed to detect some elements of Mendeleev's classification in pathogenic fungi for humans. X-ray microanalysis applied in wavelength dispersive spectrometry was used to study Coccidio?des immitis, Paracoccidio?des brasiliensis and Trichosporum cutaneum. 相似文献