Hydrophilicity and Microsolvation of an Organic Molecule Resolved on the Sub-molecular Level by Scanning Tunneling Microscopy.

Low-temperature scanning tunneling microscopy was used to follow the formation of a solvation shell around an adsorbed functionalized azo dye from the attachment of the first water molecule to a fully solvated molecule. Specific functional groups bind initially one water molecule each, which act as anchor points for additional water molecules. Further water attachment occurs in areas close to these functional groups even when the functional groups themselves are already saturated. In contrast, water molecules surround the hydrophobic parts of the molecule only when the two-dimensional solvation shell closes around them. This study thus traces hydrophilic and hydrophobic properties of an organic molecule down to a sub-molecular length scale.

Treatment of venous malformations: first experience with a new sclerosing agent--a multicenter study.

PURPOSE: To study the efficacy and safety of a new sclerosing gel of absolute ethanol in the percutaneous treatment of venous malformations (VM). MATERIALS AND METHODS: In this prospective, non-randomized multicenter study patients with clinically and by magnetic resonance imaging diagnosed VM were treated. Efficacy and safety of the gel was evaluated. Therapeutic outcome was judged at day 56 after the last sclerosing therapy. Blood ethanol levels of ethanol were measured after each infusion. Local and systemic adverse events were recorded. RESULTS: Seventy-five (75) patients (age 4-46 y, mean 26 y) were treated in 172 sessions. Compared to no treatment, ethanol gel showed a complete cure rate of about 15% per session (p<0.00001). At the end of the last session, therapeutic outcome was complete (score 2) and partial (score 1) in 28 (37%) and 42 patients (56%), respectively, whereas treatment failure (score 0) was observed in 5 patients (7%). The plasmatic ethanol levels were very low (mean±SEM 0.03±0.06 g L(-1)), with only one patient above the legal 0.5 g L(-1) intoxication limit (0.6 g L(-1)). Forty-six (46) product-related adverse events (all local, none systemic) were reported. They included temporary mild isolated pain (N=21), inflammatory reactions (N=4), and local complications (7 skin necroses, 7 compressive neuropathies, 4 product leakage/fistula, 2 intralesional fibrous or granulomatous tissue, 1 dense node; 12.2% of the infusions). All local complications resolved spontaneously, except for 2 skin necroses requesting surgical paring. CONCLUSION: Ethanol gel is an embosclerosing substance that provides high efficiency and improves safety of ethanol in the treatment of VM lesions.

Altered expression patterns of EphrinB2 and EphB2 in human umbilical vessels and congenital venous malformations.

Vascular malformations cause discomfort and pain in children and are often associated with skeletal hypertrophy. Their molecular basis is poorly understood. Ephrin ligands and Eph receptor tyrosine kinases are involved in embryonic vascular development. In mice, some ephrin/Eph family members show a complementary expression pattern in blood vessels, with ephrinB2 being expressed on arterial and EphB4 on venous endothelium. Targeted deletions of the genes reveal their essential roles for conduit vessel development in mice, suggesting similar functions during human vascular development and deregulation in vascular malformations. Here, we have defined the expression patterns of human ephrinB2, EphB4, and EphB2 in normal vessels of neonates (i.e. umbilici) and adults and compared them with those in congenital venous malformations. In adults, normal vessels of the skin, muscle, and legs express ephrinB2 and EphB2 on arterial endothelial cells (ECs), whereas EphB4 is found in arteries and veins. In the umbilicus, EphB2 is a specific marker of arterial ECs, whereas ephrinB2 is additionally expressed in venous ECs, suggesting an arterial function of the veins. In venous malformations, the expression of EphB4 is not altered, but both ephrinB2 and EphB2 are ectopically expressed in venous ECs. This may reflect a nonphysiologic arterialization of malformed veins. Our study shows that the arterial markers ephrin B2 and EphB2 are expressed in a subset of veins, and it remains to be studied whether this is cause or consequence of an altered vascular identity.