AIDS primary central nervous system lymphoma: molecular analysis of the expressed VH genes and possible implications for lymphomagenesis

AIDS-associated primary central nervous system lymphomas are late events that have an extremely poor prognosis. Despite different hypotheses, the brain localization of these B cell lymphomas remains an enigma. To better define the cell origin of the lymphomas and the possible role of the B cell receptor (BCR) in the brain localization and/or in the oncogenic transformation, we analyzed the V region genes of the Ig heavy chain expressed by lymphoma cells in five randomly selected patients. After amplifying the rearranged VHDJH DNA by PCR, cloning, and sequencing of the amplified products, we observed that: 1) of the five lymphomas analyzed, four were clearly monoclonal; 2) there was no preferential use of one peculiar VH family or one peculiar segment of gene; 3) the mutation analysis showed that an Ag-driven process occurred in at least two cases, probably before the oncogenic event; and 4) there was no intraclonal variability, suggesting that the hypermutation mechanism is no longer efficient in these lymphoma B cells. Taken together, our results suggest that distinct Ags could be recognized by the BCR of the lymphoma cells in different patients and that, if the Ags are responsible for the brain localization of these B cells bearing mutated BCR, other factors must be involved in B cell transformations in primary central nervous system lymphoma.     

制浆造纸科学的方程范例：含义及其应用

本文介绍了制浆造纸科学中用于预测主要参数对产品和工艺过程影响的方程范例。一些方程是很久以前由其他学科导出的,沿用于制浆造纸工程技术;另一些方程是制浆造纸研究人员根据基本原理开发的,以解决现有科学未能解决的特别问题。本文简要描述了这些方程的由来、含义和应用,其中"纸浆纤维絮凝的聚集数"以前鲜有提及。     

Comparison of total antioxidant potential,and total phenolic,nitrate, sugar,and organic acid contents in beetroot juice,chips, powder,and cooked beetroot

Beetroot is a vegetable rich in nitrate (NO ₃ ^? ), antioxidants and phenolic compounds that are related to improvements in cardiovascular function and exercise performance. However, it is unknown if convenient forms of beetroot administration provide different amounts of these nutrients. The total antioxidant potential (TAP), total phenolic (TPC), sugar, organic acid, and NO ₃ ^? contents of beetroot juice (BJ), chips (BC), powder (BP), and cooked beetroot (CB) were compared. Significant (p<0.01) differences in chemical compositions and functional properties were found between beetroot formulations. Higher amounts of TAP and organic acids were observed in BC and BP, compared with the other formulations. BJ exhibited the highest contents of total sugars, TPC, and NO ₃ ^? . All beetroot formulations were suitable and advantageous based on taste preferences and convenience for consumers and for nutrient amounts required to meet dietary recommendations.