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RA Silva G Morales E Eulert A Montenegro R Yba?ez 《Canadian Metallurgical Quarterly》1998,76(1-2):153-157
Some new commercial methods for the extraction of viral RNA have been introduced recently. In addition to the study published previously (Verhofstede, C., Reniers, S., Van Wanzeele. F., Plum J., 1996. AIDS 8, 1421-1427), seven different methods (four newly developed and three reference methods) for extraction of HIV-1 RNA from plasma have been evaluated. The RNA preparation method that gave the best results (acceptable reproducibility, highest sensitivity, reasonable price, fast and easy to perform), was the QIAamp Viral RNA kit from QIAgen. The High Pure Viral RNA Kit (Boehringer Mannheim) as well as the non-commercialised extraction kits were also very sensitive. The non-commercial tests seem less suitable for routine use and for the processing of large number of samples. Two methods, RNA Insta-Pure LS (Eurogentec) and PANext RNA extraction kit 1 (NTL, PANsystems GmbH) are not adapted for HIV plasma extraction. The single step methods using glass fibre or silica column are rapid (from 60 to 75 min depending on the number of wash steps) and although the price is high they are cheaper than the Boom extraction methods: High Pure Viral RNA Kit (Boehringer Mannheim) ($3.3/sample), QIAamp Viral RNA Kit (Qiagen) ($3.6/sample), Boom extraction ($5/sample). The Qiagen kit is the only kit that combines sensitivity with reproducibility, it is commercialised, rapid and affordable in price and can be automated. For most of the methods evaluated the inter-test variability was acceptable (mean variation coefficient between duplicate extractions varied between 26.4 and 48.6%). 相似文献
985.
D Mion Júnior E Lima Júnior FA Almeida H Chaves JC Rocha JC Nicolau M Sarago?a N Spritzer O Kohlmann Júnior RL Luna 《Canadian Metallurgical Quarterly》1993,60(3):203-208
To examine the intra-individual heterogeneity of the local inflammatory infiltrate in metastases of untreated melanoma patients we analysed 42 skin and subcutaneous metastases from 11 patients. Metastases were excised on the same date (10 patients) or consecutively (six patients), and processed in a two-step immunoperoxidase technique using monoclonal antibodies directed against T-cells (CD3, CD25) and two macrophage subpopulations (RM 3/1, 27E10). The number of positively stained T-cells and macrophages were counted for each lesion in representative high power fields. The mean values were calculated. We observed limited heterogeneity among T-cells (CD3+) and activated T-cells (CD25+) in simultaneously excised metastases. Contrary to this, markedly heterogeneous CD3+ infiltrates were found in metastases taken on different dates, even if there was a time difference of only 1 day between excisions, suggesting spontaneous variations. However, activated T-cells in follow-up biopsies showed only limited heterogeneity. In spite of inter-individual variations, metastases taken simultaneously, as well as consecutively, showed little intra-individual heterogeneity with respect to macrophages. Our findings should be taken into account for comparative studies of the infiltrate in metastatic melanoma during immunotherapy. 相似文献
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987.
988.
R. Ushatov H. Power J. J. Rê go Silva 《Engineering Analysis with Boundary Elements》1994,13(4):371-381
In this work, uniform bicubic B-spline functions are used to represent the surface geometry and interpolation functions in the formulation of boundary-element method (BEM) for three-dimensional problems. This is done as a natural generalization of cubic B-spline curves, introduced by Cabral et al, for two-dimensional problems. Three-dimensional scalar problems, with particular applications to Laplace and Helmholtz equations, are considered. 相似文献
989.
A protocol was designed for the rapid and efficient construction of cosmid libraries from cell-associated viral genomes available in very low quantities. Purification of viral DNA from cellular DNA was unnecessary. The vast excess of cellular DNA compensated for the limited amount of available viral DNA, enabling titration of the restriction endonuclease partial digest. A cosmid library of the turkey herpesvirus DNA genome was constructed from 1.5 micrograms of cellular DNA containing approximately 6 nanograms of viral DNA. 相似文献
990.
G. Vale A. Rodrigues A. Rocha R. Rial A.M. Mota M.L. Gonçalves L.P. Fonseca J.L. Capelo 《Food chemistry》2010
The suitability of hyphenated USAED with HPLC separation and ET-AAS determination as a new rapid methodology for Se control in Se-enriched food supplements is demonstrated. Total Se determination and Se speciation are accomplished in a single sample treatment using low sample amounts (ca. 10 mg), and low extracting volume (1 mL). The total Se content in seven of the 10 Se-enriched supplements studied was in agreement with the values obtained after microwave pressurized acid digestion, MW, (test t, p = 0.05). The Se species studied were Se(IV), Se(VI), SeMet, SeMeSeCys, and SeCys2, being some of the most common found in the 10 supplements studied. Although SeMet was the Se species expected to be present at the highest concentration in most Se-enriched food supplements, we detected it in only three of the 10 samples studied. In the other seven samples, two of them had Se(IV) as the main Se species. The other five supplements had Se species that did not match with any of the five standards selected by us. We have also systematically demonstrated that ultrasonication does not alter the following Se species: Se(IV), Se(VI), SeMet, SeMeSeCys, and SeCys2. The new procedure can be easily adapted to more Se species and can be routinely used for Se control in Se-enriched food supplements. Concerning the supplements studied, our results suggest that stricter control on the Se content in enriched food supplements in terms of Se species will need to become mandatory. 相似文献