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Dive into the research topics where Masa-oki Yamada is active.

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Featured researches published by Masa-oki Yamada.


Biological Trace Element Research | 1996

Age-related change of mineral content in the human thoracic aorta and in the human cerebral artery

Yoshiyuki Tohno; Setsuko Tohno; Takeshi Minami; Masayo Ichii; Yoko Okazaki; Masako Utsumi; Fumio Nishiwaki; Yumi Moriwake; Masa-oki Yamada; Tsutomu Araki

The relative contents (RCs) of mineral elements in aortae and cerebral arteries from 23 subjects, with ages ranging between 45 and 99 yr, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium, phosphorus, and magnesium in the aortae increased markedly after the age of 70. While the RC of sulfur in aortae decreased gradually after that age. It was found that accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, and secondarily in the tunica intima. Furthermore, the RCs of calcium, phosphorus, and magnesium in cerebral arteries increased markedly after the age of 70, whereas the RC of sulfur in cerebral arteries decreased after age 70. It was found that accumulation of calcium and phosphorus in the cerebral arteries were 30 and 60%, respectively, lower than those in the aortae with ages ranging between 45 and 99 yr.


Biological Trace Element Research | 1998

Age-related changes of mineral contents in the human aorta and internal thoracic artery

Yoshiytiki Tohno; Setsuko Tohno; Takeshi Minami; Masako Utsumi; Yumi Moriwake; Fumio Nishiwaki; Masa-oki Yamada; Keizo Yamamoto; Yasuo Takano; Yuko Okazaki; Hiroshi Yamamoto

To elucidate accumulations of minerals in the human aorta and internal thoracic artery, their relative contents (RCs) of minerals were analyzed by inductively coupled plasma atomic emission spectrometry.Aortas from 47 men and 24 women subjects were examined. The ages of these subjects ranged from newborn to 99 yr. After the age of 40 yr, RCs of calcium and phosphorus began to increase, and thereafter increased stepwise in the 50s and 70s. In the 70s, their accumulations were markedly increased.Internal thoracic arteries from 16 men and 7 women subjects were examined. These subjects ranged in age from 65–93 yr. It was found that all the RCs of calcium were low, <5.0 mg/g dry wt, and there was no age-dependent increase of calcium contents in internal thoracic arteries.


Biological Trace Element Research | 1996

DIFFERENCE OF MINERAL CONTENTS IN HUMAN INTERVERTEBRAL DISKS AND ITS AGE-RELATED CHANGE

Setsuko Tohno; Yoshiyuki Tohno; Takeshi Minami; Masayo Ichii; Yuko Okazaki; Masako Utsumi; Fumio Nishiwaki; Masa-oki Yamada

To establish a difference of the relative contents (RCs) of elements among the cervical, thoracic, and lumbar intervertebral disks and its age-related change, the intervertebral disks between the axis and the sacrum, which were resected from the nine cadavers who died at 53 to 99 yr old, were analyzed by inductively coupled atomic plasma emission spectrometry. It was found that both the RCs of calcium and phosphorus were high in the cervical disks, especially the highest in the disk between the 6th and 7th cervical vertebrae, and lower in the order of the cervical, thoracic, and lumbar intervertebral disks. In regard to the RCs of sulfur and magnesium, there were no significant differences among the cervical, thoracic, and lumbar intervertebral disks. In addition, it was found that both the RCs of calcium and phosphorus in the cervical intervertebral disks started to increase in the sixth decade of life, became the highest in the eighth decade of life, and then decreased.


Biological Trace Element Research | 1999

Age-related changes of elements in human anterior cruciate ligaments and ligamenta capitum femorum

Yoshiyuki Tohno; Yumi Moriwake; Yasuo Takano; Takeshi Minami; Setsuko Tohno; Masako Utsumi; Masa-oki Yamada; Keizo Yamamoto; Yuko Okazaki; Yoshinori Takakura

To elucidate compositional changes of human ligaments by aging, the content of elements in anterior cruciate ligaments (ACLs) and ligamenta capitum femorum (LCFs) was analyzed by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 11 men and 7 women, ranging from 59 to 91 yr of age. With regard to the content of elements, the content of sulfur and iron was significantly higher in the LCFs than in the ACLs. It was found in the ACLs that the content of sulfur decreased gradually with aging, whereas the content of calcium, phosphorus, and magnesium increased progressively with aging. On the other hand, it was found in the LCFs that the content of magnesium decreased gradually with aging, whereas the content of phosphorus increased progressively with aging. The common finding that the content of phosphorus increased with aging, but the content of iron decreased, was obtained in the ACL and LCF. Regarding sexual difference, it was found in both the ACLs and LCFs that the content of phosphorus was higher in women’s ligaments than in men’s.


Biological Trace Element Research | 1999

HIGH ACCUMULATION OF CALCIUM AND PHOSPHORUS IN HUMAN ILIAC ARTERIES

Setsuko Tohno; Mitsuhiko Masuda; Yoshiyuki Tohno; Yumi Moriwake; Takeshi Minami; Masako Utsumi; Masa-oki Yamada; Hiroshi Yamamoto; Yuko Okazaki

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date.Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.


Biological Trace Element Research | 1997

HIGH ACCUMULATION OF ELEMENTS IN THE HUMAN FEMORAL ARTERY

Setsuko Tohno; Yoshiyuki Tohno; Takeshi Minami; Yuko Okazaki; Masako Utsumi; Fumio Nishiwaki; Yumi Moriwake; Takashi Naganuma; Masa-oki Yamada; Tsutomu Araki

The relative contents (RCs) of elements in the femoral arteries as well as the thoracic aorta, coronary, basilar, and radial arteries from 26 subjects within the age range between 55 and 92 yr old, were analyzed by inductively coupled plasma atomic emission spectrometry.The RCs of calcium and phosphorus in the femoral arteries started to increase before the age of 60 yr. The RCs of magnesium increased after the age of 70 yr. However, the RCs of sulfur did not change significantly within the age range between 55 and 92 yr.With regard to localization of the mineral accumulations in the femoral arterial wall, it was found that the accumulations of calcium and phosphorus occurred only in the tunica media, only in the tunica intima, or in both the tunica media and the tunica intima. The manner of accumulation of calcium and phosphorus in the femoral arterial wall was different from that in the aortic wall.The average RCs of calcium in the 26 specimens were the highest in the femoral artery, followed in descending order by the thoracic aorta, coronary, basilar, and radial arteries. The average RCs of phosphorus were highest in the thoracic aorta, followed by the coronary, femoral, basilar, and radial arteries. It is noted that the accumulation of mineral elements never occurred uniformly in all the arteries.


Biological Trace Element Research | 1998

High accumulation of minerals in the human arteries of lower limb

Setsuko Tohno; Yoshiyuki Tohno; Takeshi Minami; Yumi Moriwake; Masako Utsumi; Fumio Nishiwaki; Masa-oki Yamada; Yuko Okazaki

To elucidate accumulation of minerals in the human arteries, the relative contents (RCs) of minerals in the arteries of the upper and lower limbs were analyzed by inductively coupled plasma atomic emission spectrometry.It was found that the RCs of calcium and phosphorus in the femoral and popliteal arteries of the lower limb increased with aging, whereas those in the axillary and radial arteries of the upper limb did not increase with aging. This result indicates that higher accumulation of calcium and phosphorus occurs in the arteries of the lower limb with aging as compared with that in the arteries of the upper limb, and the prevalence of arteriosclerosis increases in the arteries of the lower limb with aging but not in the arteries of the upper limb.


Biological Trace Element Research | 1998

Age-related changes of element contents in the human meniscus

Yumi Moriwake; Yoshiyuki Tohno; Setsuko Tohno; Takeshi Minami; Masako Utsumi; Fumio Nishiwaki; Masa-oki Yamada; Hiroshi Yamamoto; Yuko Okazaki; Tadashi Fujii; Yoshinori Takakura

The relative contents (RCs) of elements in the human menisci from 23 subjects in the age range between 65 and 93 yr were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of sulfur, calcium, and phosphorus in menisci increased progressively until the 80s, being the highest in the 80s, and thereafter decreased. The RCs of magnesium in menisci increased progressively until the 90s. Regarding the medial and lateral menisci, higher RCs of magnesium and iron, and a lower RC of phosphorus were found in lateral menisci in comparison with those in medial menisci.There were sexual differences in the RCs of calcium and phosphorus of medial and lateral menisci. The RCs of calcium and phosphorus were about 50% higher in women’s menisci than in men’s. Histological examinations showed that structureless mucoid masses were observed in the menisci, with very high RCs of calcium and phosphorus being detected.


Biological Trace Element Research | 1998

A HIGH ACCUMULATION OF MINERALS IN HUMAN INTERNAL JUGULAR VEIN

Setsuko Tohno; Yoshiyuki Tohno; Takeshi Minami; Yuko Okazaki; Masako Utsumi; Fumio Nishiwaki; Yumi Moriwake; Masa-oki Yamada

To elucidate age-related changes of mineral contents in human veins, the relative contents (RCs) of elements in the human internal jugular veins, superior and inferior venae cavae, and femoral veins from 27 subjects ranging from 40 to 98 yr old were analyzed by inductively coupled plasma atomic emission spectrometry.The average RCs of calcium in the 27 specimens were the highest in the internal jugular vein, followed in descending order by the superior vena cava, femoral vein, and inferior vena cava.The RCs of calcium and phosphorus in the internal jugular veins started to increase after the age of 50 yr, became the highest in subjects in their 60s and thereafter decreased gradually. It is noted that such accumulations of minerals, similar to the internal jugular vein, were also found in the veins, such as the superior and inferior venae cavae, and femoral vein. Accumulation of minerals in the veins is different from that of arteries, which increase progressively by aging, but do not decrease.


Biological Trace Element Research | 1999

Age-related changes of element contents in human mitral and tricuspid valves.

Setsuko Tohno; Yumi Moriwake; Yoshiyuki Tohno; Takeshi Minami; Fumio Nishiwaki; Masako Utsumi; Masa-oki Yamada

To examine age-related changes of human cardiac valves, mitral and tricuspid valves were analyzed by inductively coupled plasma-atomic emission spectrometry. The subjects for mitral valves consisted of 12 men and 8 women, ranging in age from 52 to 96 yr. The subjects for tricuspid valves consisted of 11 men and 6 women, ranging in age from 52 to 93 yr. Furthermore, 16 of the samples of the cardiac valves were derived from the same subjects.The contents of calcium, phosphorus, and magnesium in the mitral valves increased progressively with advancing age and reached maximum in the 80s in regard to calcium and phosphorus and maximum in the 90s in regard to magnesium. The maximum average amounts corresponded to about three times the average contents in the 60s. In contrast, the content of sulfur in the mitral valves remained constant between the 50s and 90s.Regarding tricuspid valve, the contents of calcium, phosphorus, and magnesium scarcely increased with advancing age, except for one subject who died of chronic renal failure.Histological observations of the mitral valves revealed that deposits of calcium were present in both the elastic fibers and its degenerative tissues of the mitral valve.The present study indicates that the accumulation of calcium, phosphorus, and magnesium occurs progressively in the mitral valve with aging, but does not occur in the tricuspid valve.

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Ken Fujimori

University of Tokushima

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Kensuke Chikamori

Naruto University of Education

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