Towards an integrated microfluidic device for spaceflight clinical diagnostics Microchip-based solid-phase extraction of hydroxyl radical markers.

A microchip-based solid-phase extraction method for biological fluid small molecule analysis has been developed. Using a commercially available copolymer packed into a microchip channel, extraction and preconcentration of 2,3-dihydroxybenzoic acid (DHBA) and 2,5-DHBA from saliva was achieved. The metabolites, formed from salicylic acid by reactive oxygen species, can be used as markers of oxidative stress. The results show high recovery of both metabolites (>90+/-15% for spiked saliva) with an 80-fold concentration enhancement possible. The eluent is directly analyzed using capillary electrophoresis, with good resolution for the two metabolites. This study demonstrates the feasibility of future integrated microdevices for spaceflight small molecule biomarker analysis.

High frequency of grossly deleted nef genes in HIV-1 infected long-term slow progressors treated with Korean red ginseng.

To investigate the association between Korean red ginseng (KRG) intake in HIV-1 infected patients and the occurrence of grossly deleted nef genes (gDeltanef), we characterized nef genes in 10 long-term slow progressors (LTSP) infected with HIV-1 subtype B and 34 control patients. LTSP was defined by the annual decrease in CD4 T cells being less than 20/microl over 10 years in the absence of antiretroviral therapy. They were treated with KRG for a prolonged period. Nef genes were amplified from peripheral blood mononuclear cells (PBMC) using nested PCR and the products were sequenced directly. It was observed that the patients CD4 T cell counts decreased from 444 +/- 207/microl to 294 +/- 177/microl over 136 +/- 23 months of KRG intake. This corresponds to an annual decrease in the level of CD4 T cells of 13.3/microl. A total of 479 nef genes were amplified from 137 PBMC samples. Nine out of the 10 patients, 47 (34.3%) out of the 137 samples, and 90 out of the 479 genes revealed gDeltanef. The deletion extended outside the nef gene in 25 gDeltanef obtained from 6 patients. The proportion of samples with gDeltanef (34.3%) was significantly higher than 4.8% in control patients (P < 0.001). In addition, it significantly increased as the duration of KRG intake prolongs (P < 0.01). These data suggest that the occurrence of gDeltanef might be associated with long-term intake of KRG.