To elucidate age-related changes of the dura mater, the authors investigated age-related changes of mineral contents in the falx cerebri and the tentorium cerebelli by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 10 men and 15 women, ranging in age from 65 to 102 yr. The contents of calcium, phosphorus, and magnesium increased progressively with aging in the falx cerebri, whereas the contents of sulfur, iron, and zinc remained constant, being independent of age. In regard to the tentorium cerebelli, the contents of calcium, phosphorus, and magnesium seemed to increase progressively with aging, but the contents of sulfur, iron, and zinc hardly changed with aging. It was noteworthy that there were no significant relationships between the falx cerebri and the tentorium cerebelli in such element contents as calcium, phosphorus, magnesium, sulfur, iron, and zinc.

To examine whether an accumulation of Ca in the tissues was accompanied by an increase of Mg, the authros investigated the relationships between Ca and Mg contents in the common iliac arteries, aortic valves, xiphoid processes, costal cartilages, posterior longitudinal ligaments, trigeminal nerves, and ribs by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissections by medical students were finished, the common iliac arteries, aortic valves, xiphoid processes, bilateral the fourth costal cartilages, posterior longitudinal ligaments between the fourth and fifth cervical vertebrae, trigeminal nerves, and bilateral the sixth ribs were resected from the subjects and elements were determined. It was found that there were extremely significant direct correlations between Ca and Mg contents in all of the common iliac arteries, aortic valves, costal cartilages, posterior longitudinal ligaments, and trigeminal nerves, whereas there were significant direct correlations in both the xiphoid processes and ribs. As for the tissues containing Ca higher than 20 mg/g, the average mass ratios of Mg/Ca were similar among the seven tissues. As Ca increased in all of the common iliac arteries, aortic valves, xiphoid processes, costal cartilages, posterior longitudinal ligaments, trigeminal nerves, and ribs, Mg increased simultaneously in the seven tissues.

To elucidate compositional changes of the cartilage with aging, the authors investigated age-related changes of element contents in the xiphoid process and costal cartilage by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissection by medical students was finished, the xiphoid processes and bilateral the fourth costal cartilages were resected and element contents were determined. The subjects consisted of 17 men and 9 women, ranging in age from 52 to 96 yr. No significant correlations were found between age and the content of elements, such as Ca, P, S, Mg, Na, Zn, Fe, and Si in the xiphoid process and costal cartilage, except for S in the costal cartilage, in which an extremely significant correlation was found. With regard to the relationships among element contents, the common finding that there were significant direct correlations both between Ca and P contents and between Ca and Mg contents, whereas there were significant inverse correlations both between Ca and S contents and between P and S contents obtained in the xiphoid process and costal cartilage.

To examine whether the bone mineral density (BMD) decreases uniformly with aging in any spongy bones, the authors investigated age-related changes of BMD in the calcaneus, talus, and scaphoid bone. After the ordinary dissection by medical students was finished, calcanei, tali, and scaphoid bones were resected from the subjects, and BMDs were measured by dual-energy X-ray absorptiometry. Their BMDs seemed to decrease gradually with aging in the calcanei, tali, and scaphoid bones. It was found that there were statistically significant relationships between age and BMD in the men’s and women’s scaphoid bones, women’s tali, and women’s calcanei, but not in the men’s tali and calcanei. It should be noted that there were significant relationships between age and BMD in both men’s and women’s scaphoid bones. In regard to relationship in BMD between the bones of the upper and lower limbs in individuals, it was found that the relationship between the calcaneus and talus was higher than that between the calcaneus and scaphoid bone. This suggests that there is a higher relationship in BMD between the two tarsal bones compared with that between the tarsal and carpal bones.