STUDIES ON THE HUMAN RIB-CARTILAGE
In order to elucidate the mode of calcification and ossification of the human rib-cartilage appeared on the routine X-ray film, the histologica investigations of the human rib-cartilage were made. The rib-cartilage of 40 cadavers covering from the fetus to 76 years of age were examined radiologically, and fixed with 10% formalin. Decalcification was carried out using 10% formic acid-ion exchange resin method. The paraffin section, 5r in thickness , was stained by Hematoxylin-Eosin, Azan,
... 's Elastica, Silver impregnation and PAS stainings . On some sections, Gomori's staining and von KOssa's staining were also carried out. First, the effect of decalcification procedure on the stainability of cartilage tissue was studied. As to Hematoxylin-Eosin, Weigert's Elastica, Azan and Silver-impregnating stainings , no difference in the stainability was observed between the sections before and after the decalcification procedure ; while, the stainability of ground-substance became less in PAS staining and stainability was lost in von Kossa's staining after the decalcification procedure . These findings indicate that the choice of the staining method is important when observing the decalcified section. Consecutive sections, 7r in thickness, of the cartilage of the 1st rib of a new-born baby were projected on a paper by using microscopy, and cross-sections of the vessels on each section were traced on each paper. Following vessels on each cross section from paper to paper , three-dimensional structure of the vessels were re-constructed. This reconstruction procedure of the vessels was made as the anatomical structure of the vessels is considered to be an in-and export ways of calcium ion, thus playing an important role in the calcification and ossification of the rib-cartilage. The rib-cartilage vein, which was called as the sinusoid by the author , was lined by a layer of cuboidal cells, and has a markedly large space as compared with the accompanying arterioles. Complicated branching and joining were observed , which were similar to the sinus of the spleen. The measurement of the sinusoid was carried out by using micrometer .