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91.
GS Ogg X Jin S Bonhoeffer PR Dunbar MA Nowak S Monard JP Segal Y Cao SL Rowland-Jones V Cerundolo A Hurley M Markowitz DD Ho DF Nixon AJ McMichael 《Canadian Metallurgical Quarterly》1998,279(5359):2103-2106
Although cytotoxic T lymphocytes (CTLs) are thought to be involved in the control of human immunodeficiency virus-type 1 (HIV-1) infection, it has not been possible to demonstrate a direct relation between CTL activity and plasma RNA viral load. Human leukocyte antigen-peptide tetrameric complexes offer a specific means to directly quantitate circulating CTLs ex vivo. With the use of the tetrameric complexes, a significant inverse correlation was observed between HIV-specific CTL frequency and plasma RNA viral load. In contrast, no significant association was detected between the clearance rate of productively infected cells and frequency of HIV-specific CTLs. These data are consistent with a significant role for HIV-specific CTLs in the control of HIV infection and suggest a considerable cytopathic effect of the virus in vivo. 相似文献
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Higher levels of thymidylate synthase gene expression are observed in pulmonary as compared with hepatic metastases of colorectal adenocarcinoma 总被引:1,自引:0,他引:1
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The aim of the present investigation was to determine spin lock (SL) relaxation parameters for the normal brain tissues and thus, to provide basis for optimizing the imaging contrast at 0.1 T. 68 healthy volunteers were included. On-resonance spin lock relaxation time (T1rho) and off-resonance spin lock relaxation parameters (T1rho(off), Me/Mo), MT parameters (T1sat, Ms/Mo), and T1, T2 were determined for the cortical gray matter, and for the frontal and parietal white matters. The T1rho for the frontal and parietal white matters ranged from 110 to 133 ms and from 122 to 155 ms with locking field strengths from 50 microT to 250 microT, respectively. Accordingly, the values for the gray matter ranged from 127 to 155 ms. With a locking field strength of 50 microT, T1rho(off) for the frontal and parietal white matters were from 114 to 217 ms and from 126 to 219 ms, and for the gray matter from 136 to 267 ms with the angle between the effective magnetic field (B(eff)) and the z-axis (theta) ranging from 60 degrees to 15 degrees, respectively. The T1rho of the white and gray matters increased significantly with increasing locking field amplitude (p < 0.001). The T1rho(off) decreased significantly with increasing theta (p < 0.001). T1rho and T1rho(off) with theta > or = 30 degrees were statistically significantly shorter in the frontal than in the parietal white matters (p < 0.05). The duration, amplitude and theta of the locking pulse provide additional parameters to optimize contrast in brain SL imaging. 相似文献
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MK Hong SW Park CW Lee DH Kang JK Song JJ Kim SJ Park MK Hong GS Mintz MB Leon 《Canadian Metallurgical Quarterly》1998,82(5):670-3, A8
We evaluated the role of intravascular ultrasound (IVUS) in 16 patients with unprotected left main coronary artery (LMCA) stenting compared with 80 patients with other (non-LMCA) native coronary artery stenting and found that (1) additional high-pressure or larger size balloon dilations were more frequently performed in LMCA stenting than in non-LMCA stenting (p <0.05) and (2) after IVUS-guided stent implantation, minimum lumen area was > or = 9 mm2 in 88% of patients who underwent LMCA stenting and in 19% of those who underwent non-LMCA stenting (p <0.001). IVUS guidance may be a more important adjunctive imaging modality in the stenting of unprotected LMCA stenoses than in stenting of non-LMCA stenoses. 相似文献
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