ABSTRACT
Prenatal ultrasonography in the early third trimester showed an unusual branching pattern of the right aortic arch. Echocardiography performed 4 h after birth showed the right aortic arch with mirror-image branching, patent ductus arteriosus, and patent foramen ovale. Because the location of the ductus arteriosus was unclear on echocardiography, cardiovascular magnetic resonance imaging was performed 3 days after birth. Advanced techniques including contrast-enhanced time-resolved magnetic resonance angiography and 3D time-of-flight magnetic resonance angiography allowed accurate diagnosis of a vascular ring comprising ascending and descending aorta, right aortic arch with mirror-image branching, and diverticulum of Kommerell giving rise to a left ligamentum arteriosum. The infant had hiccups, but no other symptoms. The esophagram was negative for obstruction. The infant was closely monitored; however, she developed esophageal obstruction at 7 months of age because of the vascular ring. She underwent lysis of the left ligamentum arteriosum followed by aortopexy for relief of esophageal obstruction. This report shows the utility of neonatal cardiovascular magnetic resonance imaging to evaluate complex congenital aortic arch anomalies.
ABSTRACT
Chitosan has great potential as a pharmaceutical excipient. In this study, chitosan flake was micronized using cryo-ball and cryo-jet milling and subsequently sterilized with nitrogen plasma. Micronized chitosan was characterized by laser diffraction, scanning electron microscopy (SEM), conductometric titration, viscometry, loss on drying, FTIR, and limulus amebocyte lysate (LAL) assays. Cryo-jet milling produced mean particle size of 16.05µm, 44% smaller than cryo-ball milling. Cryomilled chitosan demonstrated increased hygroscopicity, but reduced molecular weight and degree of deacetylation (DD). SEM imaging showed highly irregular shapes. FTIR showed changes consistent with reduced DD and an unexplained shift at 1100cm(-1). Plasma treated chitosan was sterile with <2.5EU/g after low-pressure plasma and <1.3EU/g after atmospheric pressure plasma treatment. Plasma treatment decreased the reduced viscosity of chitosan flake and powder, with a greater effect on powder. In conclusion, pharmaceutical grade, sterile chitosan powder was produced with cryo-jet milling and plasma sterilization.
