Accumulation of elements in the arteries and cardiac valves of Thai with aging

To elucidate whether the extent of element accumulation in the arteries and cardiac valves with aging was different between different races, the authors investigated the accumulation of elements in the arteries and cardiac valves of the Thai with aging and the relationships among elements in the cardiac valves. After ordinary dissection at Chiang Mai University was finished, 16 arteries and 4 cardiac valves were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the 16 arteries, the average content of calcium was the highest in the site of the abdominal aorta ramifying into the common iliac arteries, and it decreased in the order internal iliac, coronary, abdominal aorta, common iliac, external iliac, superior mesenteric, inferior mesenteric, thoracic aorta, brachial, radial, common carotid, subclavian, ulnar, axillary, renal, and internal thoracic arteries. The average contents of phosphorus and magnesium in respective arteries were parallel with the average contents of calcium, except for the coronary artery. In comparison with the arteries of the Japanese, the trend of calcium accumulation in the arteries of the Thai was almost similar to that in the arteries of the Japanese, except for the coronary artery and thoracic aorta. The calcium accumulation in the coronary artery was much higher in the Thai than in the Japanese, whereas that in the thoracic aorta was lower in the Thai than in the Japanese. Regarding elements in the cardiac valves, the calcium content increased remarkably in the seventies in the aortic valve and in the nineties in the pulmonary valve, but it hardly increased in both the mitral and tricuspid valves with aging. The average content of calcium was the highest in the aortic valve, and it decreased in the order pulmonary, tricuspid, and mitral valves. Regarding the relationship among elements in the aortic valves, it was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, and magnesium, whereas there were significant direct correlations between zinc and either calcium or phosphorus contents. Although significant correlations were found between sulfur and the other element contents in the aortic valves of the Japanese, no significant correlations were found between them in the aortic valves of the Thai. In the mitral valves, extremely or very significant direct correlations were found among the contents of calcium, phosphorus, magnesium, and sulfur, with some exceptions that there were no significant correlations between phosphorus and either magnesium or sulfur contents. In addition, no significant correlation was found in the calcium content between the aortic valve and coronary artery in the same individuals.     

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

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.     

Compositional changes of the aortic valve similar to the artery with aging

To elucidate compositional changes of the cardiac valves with aging, the authors investigated the relationships among element contents in the aortic valves, in which the accumulation of calcium and phosphorus was the highest. The subjects consisted of 10 men and 14 women, ranging in age from 65 to 102 yr. Extremely significant direct correlations were found among the contents of calcium, phosphorus, magnesium, sodium, and zinc in the aortic valves. In contrast, significant inverse correlations were found between the contents of sulfur and the other elements, such as calcium, phosphorus, magnesium, and sodium. It should be noted that these correlations present in the aortic valves were very similar to those in the arteries, especially those in the thoracic aortas. The changes of the mass ratios of Mg/Ca and Mg/P in the aortic valves were similar to those in the thoracic aortas. As calcium and phosphorus increased in the aortic valve, the mass ratios Mg/Ca and Mg/P decreased reversely in the aortic valve. These results suggest that the compositional change of the aortic valve is very similar to that of the thoracic aorta.     

Earlier accumulation of calcium, phosphorus, and magnesium in the coronary artery in comparison with the ascending aorta, aortic valve, and mitral valve

To explore reasons for a high accumulation of Ca and P occurring in the coronary artery of Thai with aging, the authors investigated age-related changes of elements in the coronary artery, ascending aorta near the heart, and cardiac valves in single individuals, and the relationships in the elements between the coronary artery and either the ascending aorta or cardiac valves. After an ordinary dissection by medical students at Chiang Mai University was finished, the anterior descending arteries of the left coronary artery, ascending aortas, mitral valves, and aortic valves were resected from the subjects. The subjects consisted of 17 men and 9 women, ranging in age from 46 to 76 yr. The element content was analyzed by inductively coupled plasma-atomic emission spectrometry. The average content of Ca and P was the highest in the coronary artery and decreased in the order aortic valve, ascending aorta, and mitral valve. The Ca, P, and Mg content increased in the coronary artery in the fifties and in the ascending aorta, aortic valve, and mitral valve in the sixties. It should be noted that the accumulation of Ca, P, and Mg occurred earlier in the coronary artery than in the ascending aorta, aortic valve, and mitral valve. It was found that with respect to the Ca, P, Mg, and Na contents, the coronary artery correlated well with both the aortic valve and ascending aorta, especially with the aortic valve, but it did not correlate with the mitral valves. This finding suggests that the accumulation of Ca, P, Mg, and Na occurs in the coronary artery together with the aortic valve and ascending aorta, but not together with the mitral valve. Because regarding the accumulation of Ca, P, and Mg, the ascending aorta and aortic valve are preceded by the coronary artery, it is unlikely that the accumulation of Ca, P, and Mg spreads from the ascending aorta or aortic valve to the coronary artery.     

Heart valve macro- and microstructure

Each heart valve is composed of different structures of which each one has its own histological profile. Although the aortic and the pulmonary valves as well as the mitral and the tricuspid valves show similarities in their architecture, they are individually designed to ensure optimal function with regard to their role in the cardiac cycle.In this article, we systematically describe the structural elements of the four heart valves by different anatomical, light- and electron-microscopic techniques that have been presented. Without the demand of completeness, we describe main structural features that are in our opinion of importance in understanding heart valve performance. These features will also have important implications in the treatment of heart valve disease. They will increase the knowledge in the design of valve substitutes or partial substitutes and may participate to improve reconstructive techniques. In addition, understanding heart valve macro- and microstructure may also be of benefit in heart valve engineering techniques.     

Accumulation of calcium and phosphorus accompanied by inevitable accumulation of magnesium in human arteries

To examine whether there were differences between races in regard to the relationships among element contents in the arteries, the authors investigated the relationships among the average contents of calcium, phosphorus, sulfur, and magnesium in the 18 kinds of the Thai artery. After ordinary dissection by medical students at Chiang Mai University was finished, the thoracic and abdominal aortas, ramifying site of the abdominal aorta into the common iliac arteries, coronary, common carotid, internal thoracic, subclavian, axillary, brachial, radial, superior and inferior mesenteric, renal, common iliac, internal iliac, and external iliac arteries were resected from the subjects who consisted of 12 men and 3 women, ranging in age from 39 to 84 yr. The femoral and posterior tibial arteries were resected from the subjects, consisting of 15 men and 5 women, ranging in age from 25 to 88 yr. The element content of the arteries was analyzed by inductively coupled plasma-atomic emission spectrometry. It was found that there were extremely significant direct correlations among the average contents of calcium, phosphorus, and magnesium in the 18 kinds of the Thai artery, but no significant correlations were found between the average contents of sulfur and elements, such as calcium, phosphorus, and magnesium. These results were in agreement with those of the Japanese arteries. Therefore, it was suggested that there was no significant difference between the arteries of the Thai and the Japanese in the relationships among calcium, phosphorus, sulfur, and magnesium.     

Compositional changes of human mitral valves with aging

To elucidate compositional changes of the mitral valve with aging, the authors investigated the relationships among element contents in the mitral valves. The subjects consisted of 10 men and 15 women, ranging in age from 65 to 102 yr. After the ordinary dissection, mitral valves, lower parts of the interventricular septa, and terminal crests containing the sinoatrial nodes were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The interventricular septa and sinoatrial nodes were used to compare with the mitral valves. With regard to the mitral valve, it was found that extremely significant correlations were found among the contents of Ca, P, Mg, and Na, but no significant correlations were found between the contents of S and elements such as Ca, P, or Mg. Regarding the interventricular septum, it was found that an extremely significant correlation was found between P and S contents; very significant correlations were found between Ca and Mg contents and between Mg and S contents; and a significant correlation was found between P and Mg contents. However, no significant correlation was found between Ca and P contents in the interventricular septa. In the terminal crest containing the sinoatrial node, significant correlations were found among the contents of Ca, P, Mg, and S. The present study revealed that with regard to the relationships among element contents, the compositional change of the mitral valve was intermediate between those of the thoracic aorta and the interventricular septum.     

Age-related changes of elements in human ureter

To elucidate changes of the ureter with aging, the authors investigated age-related changes of element contents in human ureters. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The contents of calcium, sulfur, and iron in the ureters increased progressively with aging, whereas the contents of phosphorus and magnesium did not increase with aging. Significant relationships were found both between calcium and sulfur contents and between calcium and iron contents in the ureters, but not between calcium and either phosphorus or magnesium contents. It was noteworthy that a significant relationship was also found between sulfur and iron contents in the ureters. It remains uncertain whether calcium forms a compound with sulfur or iron in aged human ureters or not.     

Relationships among element contents in the medial meniscus

To elucidate compositional changes of elements in the meniscus with aging, the authors investigated the relationships among elements in the medial meniscus by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 16 men and 7 women, ranging in age from 65 to 93 yr. In the left medial meniscus, extremely significant correlations were found both between calcium and phosphorus contents and between sulfur and magnesium contents, whereas significant correlations were found between calcium and either iron or zinc contents, between phosphorus and either iron or zinc contents, and between iron and zinc contents. On the other hand, in the right medial meniscus, there were only an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents. The common finding between the left and right medial menisci was an extremely significant correlation between calcium and phosphorus contents and a significant correlation between sulfur and magnesium contents.     

Coronary artery anomalies and aortic valve morphology in the Syrian hamster

In the Syrian hamster, anomalies in the origin of the left coronary artery are significantly associated with the bicuspid condition of the aortic valve. In this species, bicuspid aortic valves are expressions of a trait, the variation of which takes the form of a phenotypic continuum, ranging from a tricuspid aortic valve with no commissural fusion to a bicuspid aortic valve with the aortic sinuses located in ventrodorsal orientation and devoid of any raphe. The intermediate stages of the continuum are represented by tricuspid aortic valves with a more or less extensive fusion of the ventral commissure and bicuspid aortic valves with a more or less developed raphe located in the ventral aortic sinus. The present study was designed to decide whether there is a gap between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies, or whether this incidence varies according to the different tricuspid and bicuspid morphotypes of the continuum. The study was carried out in Syrian hamsters belonging to a single inbred family with a high incidence of tricuspid aortic valves with fusion of the ventral commissure, bicuspid aortic valves, and anomalies in the origin of the left coronary artery, i.e. single right coronary artery ostium in aorta, anomalous origin of the left coronary artery from the pulmonary artery, and anomalous origin of the left coronary artery from the dorsal aortic sinus. The specimens were examined by means of a stereomicroscope and, in several cases, scanning electron microscopy was also used. The relationships between anomalous coronary artery patterns and aortic valve morphologies were tested using a logistic regression model. The results obtained indicate that there is no discontinuity between tricuspid and bicuspid aortic valves regarding the incidence of coronary artery anomalies. The probability of occurrence of anomalous coronary artery patterns increases continuously according to the deviation degree of the aortic valve from its normal (tricuspid) design. The present findings suggest that in the Syrian hamster, the morphogenetic mechanisms involved in the formation of congenital anomalous aortic valves and anomalies in the origin of the left coronary artery, respectively, are strongly related from an aetiological viewpoint.     

Osteogenesis inducers promote distinct biological responses in aortic and mitral valve interstitial cells

Both aortic and mitral valves calcify in pathological conditions; however, the prevalence of aortic valve calcification is high whereas mitral valve leaflet calcification is somewhat rare. Patterns of valvular calcification may differ due to valvular architecture, but little is known to that effect. In this study, we investigated the intrinsic osteogenic differentiation potential of aortic versus mitral valve interstitial cells provided minimal differentiation conditions. For the assessment of calcification at the cellular level, we used classic inducers of osteogenesis in stem cells: β-glycerophosphate (β-Gly), dexamethasone (Dex), and ascorbate (Asc). In addition to proteomic analyses, osteogenic markers and calcium precipitates were evaluated across treatments of aortic and mitral valve cells. The combination of β-Gly, Asc, and Dex induced aortic valve interstitial cells to synthesize extracellular matrix, overexpress osteoblastic markers, and deposit calcium. However, no strong evidence showed the calcification of mitral valve interstitial cells. Mitral cells mainly responded to Asc and Dex by cell activation. These findings provide a deeper understanding of the physiological properties of aortic and mitral valves and tendencies for calcific changes within each valve type, contributing to the development of future therapeutics for heart valve diseases.     

Accumulation of calcium and phosphorus in the mitral valve in comparison with the abdominal aorta and the scaphoid bone

To clarify why calcification of the mitral valve occurred, the authors chose the abdominal aorta and the scaphoid bone among many arteries and bones, and they studied both relationships in element contents between the mitral valve and the abdominal aorta and between the mitral valve and the scaphoid bone. The subjects consisted of 11 men and 8 women, ranging in age from 52 to 96 yr. The accumulation of calcium and phosphorus occurred progressively with aging in the mitral valve, whereas it became the highest in the sixties in the abdominal aorta and did not increase thereafter. The accumulation of calcium and phosphorus occurred in the abdominal aorta earlier than the thoracic aorta, in which it became remarkable in the seventies. It should be noted that in regard to the accumulation of calcium and phosphorus, no significant correlations were found between the mitral valve and the abdominal aorta. It is suggested that calcification of the abdominal aorta is not essentially accompanied by calcification of the mitral valve. The scaphoid bone was chosen among many bones consisting mainly of spongy bone and the relationship was examined between the calcium content in the mitral valve and the bone mineral density of the scaphoid bone. It was found that there was a low relationship between them. Therefore, it is suggested that a part of the surplus calcium released from bones is deposited in the mitral valve.     

Age-dependent increases of calcium and phosphorus in human epiglottal cartilage

To elucidate compositional changes of the elastic cartilage with aging, the authors investigated age-related changes of elements in the epiglottal cartilages by inductively coupled plasma-atomic emission spectrometry. After the ordinary dissection by medical students at Chiang Mai University was finished, the epiglottises were resected from the subjects. The epiglottal cartilages were isolated and the element contents were determined. The subjects consisted of 11 men and 14 women, ranging in age from 39 to 92 yr old. It was found that although the extent of accumulation of calcium and phosphorus was slight, calcium and phosphorus increased progressively in the epiglottal cartilages with aging. In contrast, sulfur, magnesium, zinc, iron and sodium did not change significantly in them. Regarding the relationships among elements, it was found that there were significant correlations among calcium, phosphorus, magnesium, and sodium in the epiglottal cartilages, with one exception between calcium and sodium contents. In comparison between men and women, no significant differences were found in the predominant elements such as calcium, sulfur, and phosphorus in the epiglottal cartilages.     

Accumulation of magnesium as well as calcium and phosphorus in Japanese monkey arteries with aging

To examine whether an accumulation of elements in the arteries with aging differs between human and animal, the authors investigated the relationships among element contents in the arteries of the Japanese monkeys. The Japanese monkeys consisted of five males and four females, ranging in age from 2 to 29 yr. The aorta, common and external iliac, femoral, common carotid, subclavian, and axillary arteries were resected from the monkeys and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that there were very high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in all of the monkey arteries. In addition, significant correlations were found among the other element contents in some, but not all of the arteries. These results were consistent with the foregoing findings of the human arteries. It is likely that magnesium forms compounds with phosphorus or calcium in the monkey arteries.     

Relationships among element contents in the internal jugular vein similar to the arteries

To elucidate compositional changes of the veins with aging, the authors investigated the relationships among element contents in the internal jugular veins, in which a higher accumulation of calcium and phosphorus occurred with aging. The subjects consisted of 15 men and 10 women, ranging in age from 40 to 98 yr. The element contents of the internal jugular veins were determined by inductively coupled plasma-atomic emission spectrometry. It was found that there were extremely significant direct correlations among the contents of calcium, phosphorus, magnesium, and sodium in the internal jugular vein. In addition, very significant direct correlations were also found both between zinc and either iron or silicon contents and between sulfur and iron contents in the vein. As calcium and phosphorus increased in the internal jugular vein, the mass ratios of Mg/Ca and Mg/P decreased gradually in the vein, whereas the mass ratio of Ca/P hardly decreased. These results indicated that with regard to both the relationships among the contents of calcium, phosphorus, and magnesium and the changes of the mass ratios of Mg/Ca and Mg/P, the internal jugular vein was very similar to the arteries.     

Increases of calcium and magnesium and decreases of phosphorus and iron with aging in human uterine tubes

To elucidate compositional changes of the uterine tube by aging, the authors studied age-related changes of elements in human uterine tubes by inductively coupled plasma-atomic emission spectrometry. The uterine tubes were resected postmortem or surgically removed from patients with uterine myoma. It was found that the contents of calcium and magnesium increased progressively with aging in uterine tubes, whereas the contents of phosphorus and iron decreased gradually with aging. The sulfur content of uterine tubes remained constant and independent of aging. Regarding relationships between elements, significant relationships were found between calcium and magnesium contents, between phosphorus and iron contents, between phosphorus and sulfur contents, and between phosphorus and sodium contents in human uterine tubes.     

Simultaneous accumulation of magnesium with calcium and phosphorus in aorta and iliac arteries of thai

To elucidate compositional changes of arteries with aging, the authors previously investigated age-related changes of mineral contents in the various arteries of Japanese and Japanese monkey. To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the arteries of Thai. The subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr. After the ordinary dissection at Chiang Mai University was finished, abdominal aortas, common iliac, internal iliac, and external iliac arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. The contents of calcium, phosphorus, and magnesium became the highest in the fifties in the abdominal aorta, common iliac, and external iliac arteries, whereas the contents of calcium and magnesium became the highest in the sixties in the internal iliac artery, and decreased thereafter. In regard to relationships among element contents, it was found that there were high correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium in all of the abdominal aortas and three iliac arteries. The mass ratios of magnesium to calcium and phosphorus were each similar in the abdominal aorta, common iliac, and internal iliac arteries, except for the external iliac artery, in which it was slightly high. These revealed that as calcium and phosphorus increased in the arteries with aging, magnesium increased in the arteries as well. The differences between the arteries of Thai and Japanese were discussed in the present article.     

Simultaneous accumulation of calcium, phosphorus, and magnesium in various human arteries

To elucidate compositional changes of the arteries with aging, the authors investigated the relationships among average contents of calcium, phosphorus, sulfur, and magnesium in the arteries by inductively coupled plasma-atomic emission spectrometry. The arteries used were the thoracic and abdominal aortas, coronary, common carotid, anterior, middle and posterior cerebral, vertebral, basilar, internal thoracic, axillary, radial, truncus celiacus, common, internal and external iliac, femoral, popliteal, and umbilical arteries. It was found that high correlations were found between the average contents of calcium and phosphorus, between the average contents of calcium and magnesium, and between the average contents of phosphorus and magnesium in the arteries, but not between the average contents of sulfur and the other elements. These correlations revealed that as the content of calcium and phosphorus increased in the arteries, the magnesium content increased simultaneously in the arteries, but the sulfur content did not. It is likely that magnesium forms compounds with phosphorus in the arteries.     

High accumulation of calcium and phosphorus in the coronary artery of the Thai in comparison with the Japanese

To examine whether there were differences between races in regard to age-related changes of mineral contents and the relationships among element contents in the arteries, the authors investigated the coronary arteries of Thai and Japanese. The Thai subjects consisted of 13 men and 3 women, ranging in age from 39 to 84 yr, whereas the Japanese subjects consisted of 17 men and 9 women, ranging in age from 55 to 92 yr. After the ordinary dissections at Chiang Mai University and Nara Medical University were finished, the coronary arteries were resected and the element contents were determined by inductively coupled plasma-atomic emission spectrometry. In the Thai, an accumulation of calcium and phosphorus began to occur in the forties and increased markedly in the fifties, whereas in the Japanese, an accumulation of calcium and phosphorus began to occur in the seventies and increased markedly in the nineties. The result revealed that an accumulation of calcium and phosphorus occurred earlier in the Thai than in the Japanese. Regarding the relationships among element contents, extremely significant correlations were found between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents in both the coronary arteries of the Thai and the Japanese. As far as the coronary arteries with a very high accumulation of calcium and phosphorus, the mass ratios of magnesium to calcium and phosphorus were lower in the coronary arteries of the Thai in comparison with the Japanese.     

Age-related changes of elements in human thoracic ducts and azygos veins and relationships among elements

To elucidate compositional changes of the thoracic duct with aging, the authors investigated age-related changes of elements in the thoracic ducts in comparison with the azygos veins. The subjects consisted of 22 men and 1 woman, ranging in age from 65 to 95 yr. After ordinary dissection, the thoracic ducts and azygos veins were resected from the subjects and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that calcium appeared to increase in the thoracic duct with aging, but the other elements, such as phosphorus, sulfur, magnesium, iron, zinc, and sodium, did not change significantly with aging. In the azygos vein, both calcium and sulfur increased significantly with aging. Regarding the relationship among elements, extremely significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in the thoracic ducts, except for phosphorus and magnesium contents with a very significant direct correlation. In the azygos veins, significant direct correlations were found between calcium and sulfur contents and between sulfur and magnesium contents. However, no significant correlations were found among calcium, phosphorus, and magnesium in the azygos veins. These results revealed that with regard to the relationship among calcium, phosphorus, and magnesium, the thoracic duct was similar to the arteries, but not to the azygos vein.