PubMed · 13999998
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R van WERING. 1962. [A coagulation defect].. https://pubmed.ncbi.nlm.nih.gov/13999998/
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2',3'-Dideoxycytidine (DDC) is a nucleoside reverse transcriptase inhibitor that has been shown to inhibit the human immunodeficiency virus (HIV). DDC is a candidate for treatment of pregnant women to prevent prenatal transmission of HIV/AIDS to their unborn children. A quick and simple high-performance liquid chromatography (HPLC) method has been developed and validated for the determination of DDC concentrations in samples collected from a pregnant rat model (maternal plasma, amniotic fluid, placental and fetal tissues). Extraction of DDC and its internal standard 2',3'-dideoxy-3'-thiacytidine (3TC) in plasma and amniotic fluid was carried out by protein precipitation. Extraction from placental and fetal homogenates was achieved by solid phase extraction using Waters Oasis HLB solid phase extraction cartridges. Chromatographic separation was achieved on a Waters Spherisorb S3W silica column (4.6 mm x 100 mm) equipped with a Phenomenex guard column. The mobile phase used was 10% methanol in water with 22 mM formic acid. The flow rate was 0.5 ml/min, and the detection wavelength was optimized at 275 nm. Under these chromatographic conditions, DDC eluted around 12 min, and 3TC eluted around 10 min. The calibration curves for each day of validation and analysis showed good linear response through the range of 0.15-75.0 microg/ml in each of the four matrices. The relative recovery for DDC in each of the matrices ranged from 87.8% to 103.0%. Acceptable intra- and inter-day assay precision (<15% R.S.D.) and accuracy (<15% error) were observed over 0.15-75.0 microg/ml for all four matrices.
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The potency of TCR signaling during primary CD4+ T cell activation influences initial cytokine expression patterns and subsequent polarization toward either Th1 or Th2 subsets. In this study, we demonstrate that the T cell inhibitor placental protein 14 (PP14; glycodelin) preferentially inhibits Th1 cytokine responses and chemokine expression when present during ex vivo priming of CD4+ T cells. PP14 synergizes with exogenously added IL-4 in skewing T cell responses. Significantly, PP14 impairs the down-regulation of GATA-3 transcriptional regulator expression that normally accompanies T cell activation, which is a prerequisite for Th1 development. Taken together, these data document for the first time the ability of PP14 to skew Th responses.