This study was performed to radiographically examine the prevalence of aspiration sites and to evaluate their atomical correlation with the bronchial pattens. Ten healthy beagle dogs were repeatedly radiographed, at weekly intervals, in the left and right lateral, ventrodorsal (VD) and dorsoventral (DV) positions. Three mililiters of iohexol distilled with same volume of saline was infused into the tracheal inlet. Which lung lobe was aspirated was decided upon by the presence of a significant alveolar pattern due to the contrast medium. Alveolar patterns were identified at the left (100%) and right cranial lung lobes (77%) with the dogs in dependant lateral recumbency, at the right caudal lung lobe (71%) with the dogs in VD recumbency and at the right middle lung lobe (59%) with the dogs in DV recumbency, respectively. The anatomical correlation was evaluated by performing computed tomography. The right principal bronchus (165.8 +/- 1.6 degrees) was more straightly bifurcated than was the left principal bronchus (142.7 +/- 1.8 degrees, p < 0.01). In VD position, the right side lung had a greater opertunity to become aspirated. The ventrally positioned right middle lobar bronchial origin was more easily to be aspirated the other laterally positioned ones. We think that these anatomical characteristics can be one of the causes for aspiration pneumonia to occur more frequently in the right side lung.
Animals ; Contrast Media/chemistry ; Dog Diseases/pathology/*radiography ; Dogs ; Female ; Iohexol/chemistry ; Male ; Pneumonia, Aspiration/pathology/radiography/*veterinary ; Tomography, X-Ray Computed/veterinary

The liposomes were prepared by reverse-phase evaporation technique. The morphology of the liposomes, the entrapment efficiency and the particle size distribution were evaluated. The CT signals of Iohexol liposomes in rabbits were compared with those of Iohexol injection in rabbits. The entrapment efficiency of Iohexol liposomes was 82.35% +/- 1.82%. The liposmes were spherical or ellipsoidal shape in shape. The mean diameter of the Iohexol liposomes was 207 7 nm. The polydispersity index was 0.355. The Zeta potential was--1.83 mV. The drug was highly entrapped into the liposomes with good reproduction and stability. The in vitro release of Iohexol liposomes was significantly slower than that of Iohexol,and was 98.57% at 24 h. Iohexol liposomes may reduce the dosage, prolong the effective time of the developing agent, and could reduce the side effects of Iohexol on the blood vessels and cerebral nerves.
Animals ; Contrast Media ; chemical synthesis ; chemistry ; Drug Carriers ; Drug Delivery Systems ; Iohexol ; chemical synthesis ; chemistry ; Liposomes ; administration & dosage ; chemical synthesis ; Microscopy, Electron, Scanning ; Particle Size ; Rabbits ; Random Allocation