Signal Intensity of the Cerebrospinal Fluid after Intravenous Administration of Gadolinium-based Contrast Agents: Strong Contrast Enhancement around the Vein of Labbe.

PURPOSE: Since the first report on the deposition of gadolinium in the brain parenchyma after repeated intravenous administrations of gadolinium-based contrast agent GBCA (IV-GBCA), the mechanisms of penetration and retention are still remaining a hot topic of discussion and a target of investigation. We routinely obtain endolymphatic hydrops (EH) images at 4 h after IV administration of a single dose (SD) of GBCA (IV-SD-GBCA) using heavily T2-weighted three-dimensional fluid-attenuated inversion recovery imaging (hT2W-3D-FLAIR). Occasionally, we have encountered cases, which indicate high-signal intensity (SI) in the cerebrospinal fluid (CSF) surrounding the vein of Labbe. The purpose of the present study was to investigate the degree of contrast enhancement of the CSF surrounding the vein of Labbe on hT2W-3D-FLAIR after IV-SD-GBCA in comparison with other CSF spaces. MATERIALS AND METHODS: In 25 patients with a suspicion of EH, a magnetic resonance cisternography (MRC) and an hT2W-3D-FLAIR were obtained at 4 h after IV-SD-GBCA. The perivascular space (PVS) in the basal ganglia, CSF spaces in the ambient cistern (CSF-Amb), the CSF surrounding the superficial middle cerebral vein (CSF-SMCV), and the CSF surrounding the vein of Labbe (CSF-VL) were segmented on MRC. The PVS and CSF regions were co-registered onto the hT2W-3D-FLAIR and the SI of the PVS and CSF spaces were measured. The SI ratio (SIR) of the post-contrast hT2W-3D-FLAIR to the pre-contrast hT2W-3D-FLAIR was measured. Significant differences were evaluated using Steel-Dwass's test for multiple comparisons. RESULTS: The SIR of the CSF-VL was significantly higher than that of the PVS (P = 0.008), the CSF-Amb (P = 0.021), and the CSF-SMCV (P = 0.023). CONCLUSION: The strong contrast enhancement of CSF space around the vein of Labbe was confirmed on hT2W-3D-FLAIR at 4 h after IV-GBCA compared to the PVS and the other CSF spaces.

ATML1 and PDF2 Play a Redundant and Essential Role in Arabidopsis Embryo Development.

The epidermis of shoot organs in plants develops from the outermost layer (L1) of the shoot apical meristem. In Arabidopsis, a pair of homeobox genes, ARABIDOPSIS THALIANA MERISTEM LAYER1 (ATML1) and PROTODERMAL FACTOR2 (PDF2), play a role in regulating the expression of L1-specific genes. atml1-1 pdf2-1 double mutants show striking defects in the differentiation of shoot epidermal cells. However, because atml1-1 and pdf2-1 have a T-DNA inserted downstream of the respective homeobox sequences, these alleles may not represent null mutations. Here we characterized additional mutant alleles that have a T-DNA insertion at different positions of each gene. Double mutants of a strong atml1-3 allele with each pdf2 allele were found to cause embryonic arrest at the globular stage. Although with low frequency, all double mutant combinations of a weak atml1-1 allele with each pdf2 allele germinated and showed phenotypes defective in shoot epidermal cell differentiation. We further confirmed that transgenic induction of PDF2 fused to the Drosophila Engrailed repressor domain temporarily interferes with epidermal cell differentiation in the wild-type background. These results indicate that ATML1 and PDF2 act redundantly as a positive regulator of shoot epidermal cell differentiation and at least one copy of these genes is essential for embryo development.

Characteristic odor components of Citrus reticulata Blanco (ponkan) cold-pressed oil.

Citrus reticulata Blanco (ponkan) cold-pressed oil and its oxygenated fraction were studied by analytical (GC and GC/MS) and sensory analyses. The monoterpene group was predominant, accounting for more than 89.6% (w/w), of which limonene was the most abundant (80.3%). Among the oxygenated compounds, octanal and decanal were the major ones among 12 aldehydes accounting for >1.5%; six alcohols were identified with a total concentration of >0.7%, while oxides, ketones and esters did not quantitatively or qualitatively contribute to the oil. Sniffing the ponkan cold-pressed oil and its oxygenated fraction demonstrated that octanal and decanal were the characteristic odor components of ponkan. Reconstruction of the ponkan aroma model and its sensory evaluation by a hedonic test were performed, showing that, in addition to octanal and decanal which played important roles, (R)-(+)-limonene contributed to the aroma model as a background component, making the aroma model very similar to that of the original.