The fetal frontomaxillary facial angle in normal and trisomy 21 ultrasounds at 11-13(+6) weeks of gestation: findings among the ethnic Chinese compared with Caucasian.

OBJECTIVE: The aim of this research was to compare the fetal frontomaxillary facial (FMF) angle between normal and trisomy 21 fetuses at 11(+0) -13(+6) weeks gestation in a Chinese population. METHODS: A prospective observational study was performed that included 640 euploid and 45 trisomy 21 singleton pregnancies undergoing first trimester ultrasound screening between 11 and 13(+6) weeks of gestation. The FMF angle was measured in the midsagittal plane using the standard technique. RESULTS: The fetal mean FMF angle decreased with the increasing crown-rump length (CRL) from 88.6°at a CRL of 45 mm to 78.5° at a CRL of 84 mm (FMF angle = 100.212 - 0.258 × CRL, R(2) = 0.222, p < 0.001). The overall mean FMF angle in the euploid population was 82.9° ± 4.1° and in trisomy 21 cases, 92.3° ± 5.2°. CONCLUSIONS: Fetal FMF angle is affected by gestational age in a Chinese population, although it remains a significant predictor of fetal trisomy 21.

Integrin αvß3-targeted dynamic contrast-enhanced magnetic resonance imaging using a gadolinium-loaded polyethylene gycol-dendrimer-cyclic RGD conjugate to evaluate tumor angiogenesis and to assess early antiangiogenic treatment response in a mouse xenograft tumor model.

The purpose of this study was to validate an integrin αvß3-targeted magnetic resonance contrast agent, PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2, for its ability to detect tumor angiogenesis and assess early response to antiangiogenic therapy using dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). Integrin αvß3-positive U87 cells and control groups were incubated with fluorescein-labeled cRGD-conjugated dendrimer, and the cellular attachment of the dendrimer was observed. DCE MRI was performed on mice bearing KB xenograft tumors using either PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 or PEG-G3-(Gd-DTPA)6-(cRAD-DTPA)2. DCE MRI was also performed 2 hours after anti-integrin αvß3 monoclonal antibody treatment and after bevacizumab treatment on days 3 and 6t. Using DCE MRI, the 30-minute contrast washout percentage was significantly lower in the cRGD-conjugate injection groups. The enhancement patterns were different between the two contrast injection groups. In the antiangiogenic therapy groups, a rapid increase in 30-minute contrast washout percentage was observed in both the LM609 and bevacizumab treatment groups, and this occurred before there was an observable decrease in tumor size. The integrin αvß3 targeting ability of PEG-G3-(Gd-DTPA)6-(cRGD-DTPA)2 in vitro and in vivo was demonstrated. The 30-minute contrast washout percentage is a useful parameter for examining tumor angiogenesis and for the early assessment of antiangiogenic treatment response.

Dynamic contrast-enhanced folate-receptor-targeted MR imaging using a Gd-loaded PEG-dendrimer-folate conjugate in a mouse xenograft tumor model.

PURPOSE: The purpose of this study is to validate a folate-receptor (FR)-targeted dendrimer, PEG-G3-(Gd-DTPA)11-(folate)5, for its ability to detect FR-positive tumors, by using dynamic contrast-enhanced MRI. PROCEDURES: KB cells, FR siRNA knockdown KB cells, and FR negative HT-1080 cells, were incubated with fluorescein-labeled dendrimer and their cellular uptake was observed. Dynamic contrast-enhanced MRI was performed on mice-bearing KB and HT-1080 tumors and the enhancement patterns and parameters were analyzed. RESULTS: Green fluorescence was found in the KB cells in the cellular uptake experiment, but was not seen in other settings. In the dynamic contrast-enhanced MRI, the 30-min washout percentage was -4 +/- 18% in the KB tumors and 39 +/- 23% in the HT-1080 tumors. A 17% cut-off point gave a sensitivity of 94.4% and a specificity of 93.8%. CONCLUSIONS: We have demonstrated the targeting ability of PEG-G3-(Gd-DTPA)11-(folate)5 in vitro and in vivo. A 17% cut-off point for a 30-min washout percentage can be a useful parameter for the diagnosis of FR-positive tumors.