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Biomedical subjects

Takeshi Minami

Publications and source records attributed to Takeshi Minami.

At least 37 records · Page 2Linked to original sources

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.

Adult↗

Age-related changes of elements and relationships among elements in the common bile and pancreatic ducts.

To elucidate compositional changes of the common bile and main pancreatic ducts with aging, the authors investigated age-related changes of element contents in the common bile and pancreatic ducts by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students was finished, the common bile ducts and main pancreatic ducts (pancreatic ducts) were resected and the element contents were determined. The Mg content increased significantly only in the pancreatic duct with aging, but the other element contents did not change significantly in both the common bile and pancreatic ducts with aging. Regarding the relationships among the elements, significant direct correlations were found among the contents of Ca, P, S, and Mg in the common bile ducts, with some exceptions between P and either S or Mg contents. In the pancreatic ducts, significant direct correlations were found between S and Mg contents and between P and Na contents. The relationships in the elements between the common bile and pancreatic ducts were examined. It was found that there were significant direct correlations in the Ca, Mg, and Fe contents between the common bile and pancreatic ducts; that is, as Ca, Mg, and Fe increased in the common bile duct, they increased simultaneously in the pancreatic duct.

Aged↗

Compositional changes of the muscular layers of the stomach with aging.

To elucidate compositional changes of the stomach with aging, the authors investigated age-related changes of the elements and relationships among the elements in the muscular layers of the pylorus, cardia, lesser curvature, and greater curvature by inductively coupled plasma-atomic emission spectrometry. After ordinary dissection by medical students, the pylori, cardias, lesser curvatures, and greater curvatures were removed from the subjects, consisting of 19 men and 1 woman, ranging in age from 65 to 95 yr. The muscular layers were isolated and the element contents were determined. The calcium content increased progressively with aging in the muscular layers of the pylorus, cardia, and lesser curvature, whereas it tended to increase in the muscular layer of the greater curvature with aging. Regarding sulfur, the content increased significantly in the muscular layer of the pylorus with aging, but not significantly in the muscular layers of the cardia, lesser curvature, and greater curvature with aging. Regarding the relationships among the elements, significant direct correlations were found among calcium, phosphorus, sulfur, and magnesium in both the muscular layers of the pylori and cardias, with some exceptions.

Aged↗

High accumulation of calcium in human uterine artery with aging.

To elucidate compositional changes of the rami of the internal iliac artery with aging, the authors investigated age-related changes of the calcium content in the uterine, internal pudendal, umbilical, and obturator arteries by inductively coupled plasma-atomic emission spectrometry. After an ordinary dissection was finished, the uterine, internal pudendal, umbilical, and obturator arteries were resected from 10 female subjects, and the internal pudendal, umbilical, and obturator arteries were resected from 10 male subjects. The female subjects ranged in age from 52 to 96 yr, and the male subjects ranged in age from 63 to 88 yr. The calcium content in the uterine artery began to increase in the seventies and increased markedly in the nineties. In the internal pudendal artery, the calcium content hardly increased up to the eighties and increased significantly in the nineties. In contrast, the calcium content did not change in both the umbilical and obturator arteries with advancing age. It was found that the average content of calcium was the highest in the uterine artery and decreased in the order internal pudendal, umbilical, and obturator arteries. The average content of calcium in the uterine arteries corresponded to 46-fold the amount of the women's obturator arteries, in which it was the lowest. In the cases of men, the average content of calcium was higher in the order of the internal pudendal, umbilical, and obturator arteries. Regarding the average content of calcium, the order internal pudendal, umbilical, and obturator arteries of the men was consistent with that of the women.

Aged↗

Age-dependent decreases of sulfur and magnesium in human round ligaments of the uterus and relationships among elements.

To elucidate the compositional change of ligaments with aging, the authors investigated both age-related changes of elements and relationships among elements in the round ligaments of the uterus (round ligaments) by inductively coupled plasma-atomic emission spectrometry. The bilateral round ligaments were resected from 20 cadavers and also from the uteri removed surgically from 11 patients bearing uterine myoma or cancer. Thirty-one subjects ranged in age from 34 to 92 yr. It was found that both S and Mg decreased gradually in the round ligaments with aging, but Ca, P, Zn, Fe, and Al did not change significantly with aging. Regarding the relationships among elements, very significant direct correlations were found among the contents of Ca, P, S, and Mg in the round ligaments, whereas significant inverse correlations were found between the contents of Zn and elements, such as Ca, P, S, and Mg. It should be noted that there was an extremely significant direct correlation between Ca and P contents in the round ligaments.

Adult↗

Accumulation of calcium in human common iliac artery, aortic valve, xiphoid process, costal cartilage, posterior longitudinal ligament, trigeminal nerve, and rib accompanied by increase of magnesium.

To examine whether an accumulation of Ca in the tissues was accompanied by an increase of Mg, the authors 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.

Aged↗

Age-related changes of elements and relationships among elements in human tendons and ligaments.

To elucidate compositional changes of the tendons and ligaments with aging, the authors investigated age-related changes of element contents in the insertion tendons of the biceps brachii muscle, central tendons of the diaphragma, Achilles' tendons, posterior longitudinal ligaments (PLLs) of the cervical spine, ligamenta capitum femorum, and anterior cruciate ligaments. After ordinary dissections by medical students, the three tendons and three ligaments were resected and element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that the elements, such as Ca, P, S, Mg, Na, Zn, and Fe, did not change significantly in the three tendons and two ligaments with aging, except for the PLLs where Ca and Mg increased significantly with aging and Fe decreased significantly with aging. With regard to the relationships among elements, the common finding that there were significant correlations between Ca and P contents and between Ca and Mg contents was obtained in the three ligaments. Likewise, the common finding that there was a significant correlation between Ca and Mg contents was obtained in the three tendons. Regarding the relationship between Ca and P contents, the three tendons were different from the three ligaments.

Age Factors↗

Age-related changes of elements with their relationships in human cranial and spinal nerves.

To elucidate compositional changes of peripheral nerves with aging, the authors investigated age-related changes of elements and their relationships in the optic, trigeminal, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 10 men and 12 women, ranging in age from 65 to 91 yr. It was found that although accumulations of Ca and P occurred only in the trigeminal nerve at old age, it hardly occurred in the optic, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves at old age. The average contents of Ca and P were three and two times higher in the trigeminal nerve than in the other nine kinds of nerve, respectively. Likewise, the average content of Mg was a little higher in the trigeminal nerve compared with the other nerves. With regard to the relationships among elements, significant direct correlations were found among the contents of Ca, P, S, and Mg in most, but not all, 10 kinds of nerve. In the trigeminal nerve, a significant inverse correlation was found between the contents of S and the other elements, such as Ca, P, and Mg. Regarding the relationships between the contents of S and other elements, the nerves, except for the trigeminal nerve, differed from those found in the arteries previously reported.

Aged↗

Epigenetic system: a pathway to malignancies and a therapeutic target.

Cancer cells possess both genetic and epigenetic alterations that dysregulate essential cellular processes, leading to disordered cell proliferation and differentiation. Oncogenes and tumor suppressor genes have been found to be activated and inactivated, respectively, in malignant cells. Epigenetic regulation of the genome is mediated by interactions between DNA methylation, chromatin, and modifications of histones and various transcriptional regulators. Recent studies have shown that some components of the epigenetic system as well as epigenetically mutated genes are diagnostic and therapeutic targets in cancer. We discuss the molecular basis of the epigenetic mechanism in association with the development of cancer.

DNA Methylation↗

Transport of trace elements in lenses of normal and hereditary cataract UPL rats.

The multitracer technique was applied to the determination of the uptake of trace elements in the lenses of normal and hereditary cataract UPL rats to investigate the transport mechanisms of trace elements during cataract development. Be, Na, Sc, V, Cr, Mn, Fe, Co, Zn, As, Se, Rb, Sr, Y, Zr, Tc, Ru and Rh accumulate in normal and UPL cataract rat lenses. The rates of uptake of trace elements differ among species and also differ between normal and UPL rat lenses. The uptakes of V and Sr are greater in normal rat lenses, while the uptakes of Mn and Co are greater in UPL rat lenses. High concentrations of Zn are transported into normal rat lenses in comparison with other elements. However, the uptake of Se was highest in the lenses of UPL cataract rats. In addition, the difference in Se uptake between the normal and UPL rat lenses was greatest among the tested trace elements. The present study suggests that the transport characteristics of trace elements are different in the lenses of normal and UPL cataract rats. The different transport characteristics of trace elements in the lenses of normal and UPL cataract rats, especially the higher accumulation of Se in UPL rat lenses, may be implicated in cataract development.

Animals↗

Serum response factor is modulated by the SUMO-1 conjugation system.

Serum stimulation leads to activation of the serum response factor (SRF)-mediated transcription of immediate-early genes such as c-fos via various signal transduction pathways. We have previously reported that promyelocytic leukemia protein (PML) is involved in the transcriptional regulation by SRF. PML is one of the well-known substrates for modification by small ubiquitin-related modifier-1 (SUMO-1) and several SUMO-1-modified proteins associate with PML. Here, we report that SRF is modified by SUMO-1 chiefly at lysine(147) within the DNA-binding domain. Substitution of this target lysine for alanine did not affect the translocation of SRF to PML-nuclear bodies. The SRF mutant augmented the transcriptional activity under Rho A-stimulated condition but not under serum-starved condition, suggesting that activated SRF is suppressed by its sumoylation. These data support the transcriptional role of SUMO-1 conjugating system in cellular serum response.

Amino Acid Sequence↗

A confirmation of 125I-omega-conotoxin labeled sites in a crude membrane fraction from chick brain as the alpha1 subunit of N-type calcium channels.

Omega-conotoxin GVIA (omega-CTX), as a selective blocker for an N-type Ca2+ channel, has been conveniently used in many molecular biochemical and pharmacological experiments. There has been little elucidation of 125I-omega-CTX binding sites (mainly the 135-kDa band) in the crude membranes from chick brain, although the characteristics of specific 125I-omega-CTX binding and labeling sites in chick brain membranes have been investigated in our previous research. In this work, our goal is to further identify 125I-omega-CTX labeling sites in chick brain membranes by using anti-B1Nt antibodies (against the N-terminal segment B1Nt of N- or P-type Ca2+ channel alpha1-subunits). The 25I-omega-CTX-labeled sites in chick brain membranes could be solubilized and immunoprecipitated by using an anti B1Nt antibody. The molecular weight of the immunoprecipitated protein was determined as 135 kDa, which is inconsistent with that of the specific 125I-omega-CTX binding protein reported previously. Moreover, the 125-omega-CTX-labeled protein could be purified by the method of preparative SDS-PAGE and recognized by anti-B1Nt antibodies in Western blotting analysis. These results indicated that anti-B1Nt antibodies could truly recognize 125I-omega-CTX-labeled sites as the main band of 135 kDa from chick brain membranes, and the omega-CTX-labeled site (mainly the 135-kDa band) should be N-type Ca2+ channel alpha1-subunits.

Animals↗

Structural specificity for the inhibitory effect of calmodulin on specific 125I-omega-conotoxin GVIA binding.

To clear the structural specificity of calmodulin (CaM) on the specific 125I-omega-CTX binding to crude membranes from whole chick brain, the following experiments were investigated in this study: (i) the attenuating effect of semisynthetic tetrahydroisoquinoline derivatives on the inhibitory effect of Ca2+/CaM, (ii) the effects of chimeras of yeast and chicken Ca2+/CaM, and (iii) the effects of Ca2+-binding proteins (such as troponin c, S 100 a and b, and annexin I, III-V). The inhibitory effect of Ca2+/CaM was attenuated by isoquinoline derivatives (PX 28, 34, 216, 224, and CPU57) and a CaM antagonist W-7. PX 34, a typical synthesized isoquinoline derivative, showed the attenuating effect in a dose-dependent manner. The ED50 value for the attenuating effect of PX 34 was about 20 microM, which is similar to that of W-7 reported previously. Some chimeric CaMs such as YC 51-53 (which are close to the properties of vertebrate CaM) showed a significant inhibitory effect on the specific 125I-omega-CTX binding, but YC 129 and 130 (which retain the properties of yeast CaM), troponin c, S100 a, b, and annexin I, III-V had no effect on the specific 125I-omega-CTX binding. These results suggest that the characteristic structure containing the EF-hand structure of CaM itself is needed to cause the inhibitory effect on the specific 125I-omega-CTX binding.

Animals↗

PML-nuclear bodies are involved in cellular serum response.

BACKGROUND: Serum stimulation leads to the activation of various signal transduction pathways in cells, and the resultant signals are integrated into the serum response factor (SRF)-dependent transcription of immediate-early genes such as c-fos. RESULTS: To further characterize this response, we investigated the mechanism which controls serum response transcription in cultured human cells. Frequency of PML (promyelocytic leukaemia)-nuclear bodies (NBs) formation increases shortly after serum stimulation, probably facilitating the interaction of SRF and CBP acetyltransferase at the NBs. PML modulates SRF-mediated c-fos promoter activities upon addition of serum to cells or expression of constitutively active Rho family GTPases. We mapped the region in the SRF that interacts with PML to the C-terminal transactivation domain. An SRF mutant deleted of the transactivation domain neither co-localizes with CBP in NBs nor fulfills its transcriptional role. Under conditions of serum stimulation, the formation of NBs coincides with the immediate-early expression of the endogenous c-fos gene in fibroblasts and in all-trans retinoic acid-treated acute promyelocytic leukaemia NB4 cells. CONCLUSION: These data provide an insight into the involvement of NBs in modulating the transcription of serum-induced immediate-early genes.

Blood↗

Age-related changes of element contents in human tendon of the iliopsoas muscle and the relationships among elements.

To elucidate compositional changes of the tendons with aging, the authors investigated age-related changes of element contents in the tendon of the iliopsoas muscle by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 14 men and 14 women, ranging in age from 4 to 102 yr. The insertion tendons of the iliopsoas were removed from the cadavers after ordinary dissection and also surgically from patients with congenital dislocation of the hip. It was found that both Mg and P in the tendon of the iliopsoas muscle increased significantly with aging, but the other elements, such as S, Ca, Na, Zn, Fe, and Si, hardly changed with aging. With regard to the relationship among element contents, extremely significant correlations were found between P and S contents, between Mg and Na contents, and between S and Zn contents. In addition, very significant correlations were found between Si and either S or Zn contents. However, there was no significant correlation between Ca and P contents. These results revealed that with regard to age-related changes of element contents and the relationships among element contents, the tendon of the iliopsoas muscle was different from the Achilles tendon, in which both Mg and P decreased significantly with aging and there were significant correlations each other among the contents of S, Mg, and P.

Adolescent↗

Mass ratios of magnesium to calcium and phosphorus in the arteries of Japanese and Thai.

To elucidate quantitative changes of Ca, P, and Mg in the arteries with aging, the authors investigated changes of the mass ratios of Mg to Ca and P in the arteries of Japanese and Thai by inductively coupled plasma atomic emission spectrometry. The arteries of Japanese that were used were the thoracic and abdominal aortas, coronary, common iliac, internal iliac, external iliac, and femoral arteries, in which very high accumulations of Ca and P occurred in old age. The arteries of Thai that were used were the abdominal aorta, ramifying site of the abdominal aorta, coronary, common iliac, internal iliac, and external iliac arteries. It was found that there were extremely significant correlations both between Ca and Mg contents and between P and Mg contents in all of the arteries of the Japanese and the Thai. With regard to the mass ratio, the mass ratios of Mg to Ca ranged from 1.5% to 2.1% in the six arteries of the Japanese, except for the thoracic aorta at 3.1%, at an advanced stage of atherosclerosis, being similar to each other. In the arteries of the Thai, the mass ratios of Mg to Ca ranged from 1.9% to 3.0%, except for the coronary artery at 0.5%, at an advanced stage of atherosclerosis. The mass ratios of Mg to P ranged from 2.5% to 2.7% in the six arteries of the Japanese, except for the coronary artery at 1.8%, at an advanced stage of atherosclerosis. With regard to the arteries of the Thai, the mass ratios of Mg to P ranged from 1.9% to 3.3%, except for the coronary artery at 0.7%, at an advanced stage of atherosclerosis. These results revealed that both the mass ratios of Mg to Ca and Mg to P were almost similar among the arteries of Japanese and Thai, except for the coronary arteries. Therefore, these results suggested that the inorganic deposits in the coronary arteries of Japanese and Thai were similar to those in the intimal tunica of the thoracic aorta, whereas in the other arteries, they were similar to those in the middle tunica of the thoracic aorta.

Adult↗

Compositional changes of the xiphoid process and costal cartilage with aging.

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.

Aged↗