Determination of surface areas, volumes, and lengths of cynomolgus monkey nasal cavities by ex vivo magnetic resonance imaging.

We have used high-resolution three-dimensional magnetic resonance imaging (MRI) to measure the surface area, volume, and length of the nasal cavities of cynomolgus monkeys (10 male, six female) over a range of body weights (1.9-5.3 kg, mean 2.9 kg) and ages (8-45 months, mean 30.0 months). The measurements were carried out ex vivo on formalin-fixed, decalcified nasal cavities filled with water. Mean (standard deviation) values were 30.2 (7.2) cm(2), 2.33 (0.65) cm(3), and 3.34 (0.44) cm, respectively. Linear regression least squares best fits provide the following empirical relationships: Nasal cavity surface area (SA, cm(2)) as a function of body weight (BW, kg): SA = 15.1 + 5.1(BW), R = 0.84 Nasal cavity volume (V, cm(3)) as a function of body weight: V = 1.15 + 0.4(BW), R = 0.74 Nasal cavity length (L, cm) as a function of body weight: L = 2.43 + 0.31(BW), R = 0.84 The left and right sides of the cavity were symmetrical in both males and females and showed little anatomical variation between individuals. The perimeter of the nasal cavity was maximal at about 60% of its extent from the nares. These data can aid in extrapolating nasal dosimetric exposure indices from cynomolgus monkeys (1.9-5.3 kg) to other species.

Patterns of mucin adherence to contact lenses.

PURPOSE: Contact lens wear alters the preocular fluid through factors that include tear deposits on the lens. In the current study, lens-adherent material was extracted to assess whether contact lenses sample mucins from the preocular fluid. METHODS: Discarded extended-wear contact lenses were collected from patients with no ocular surface disease. Mucins were extracted in guanidine hydrochloride (GuHCl) with protease inhibitors. After the supernatant was removed, the extraction was repeated twice with the addition of 10 mM dithiothreitol, making a total of three extractions. Mucins were isolated by cesium chloride (CsCl) gradient centrifugation and size fractionated on Sepharose CL2B. Charge distribution was analyzed on ion-exchange chromatography with a lithium perchlorate (LiClO(4)) gradient. RESULTS: Contact lens-adherent mucins comprised soluble mucins and mucins that required solubilization by (repeated) dithiothreitol treatment. MUC1, MUC4, MUC2, and MUC5AC mucins eluted mainly at low buoyant densities in extractions from lenses worn long term without disinfection and at successively higher buoyant densities from monthly disposable contact lenses. Mucins with little negative charge, which were observed in all extractions, and very highly negatively charged species, present in the second and third extractions from contact lenses, had no equivalents in tissue-extracted mucins. CONCLUSIONS: Mucins adhering to contact lenses are altered forms of intracellular mucins. Different degrees of adherence of mucins to contact lenses may occur, either because of mucin characteristics or after mucin complexation with adherent materials. In the context of good contact lens hygiene, their presence may offer some protection from toxicants in the tear film, because mucins could function as acceptors for charged moieties such as free radicals.