| Method |
Serial tissue sections
(each 3-µm thick) from the upper jaw, which were fixed with 4% formaldehyde
in PBS and decalcified with EDTA before embedding in paraffin,
were prepared and stained with H&E (Asanuma et al., 1997, PMID 9107301). The circumference of the nasal
cavity was measured based on photographs of each of the 104 tissue sections
that were taken at 110-µm intervals of the serial sections from the
nostrils to the posterior nasopharynx pore. The total surface area of
the nasal cavity was estimated by integration using the trapezoidal rule for
the surface area of 104 section blocks calculated based on both the circumference
of the nasal cavity and the thickness of the tissue blocks (113
µm). The circumference was calculated using software PIXS 2000 Ver 2.0
(Inotech, Hiroshima, Japan). |