Mineral Calcium Content Research Articles

An update on the cardiovascular pleiotropic effects of milk and milk products.

Hypertension is a major risk factor in addition to atherosclerosis and type 2 diabetes mellitus for the development of coronary heart disease and strokes. Several prospective clinical studies have demonstrated a possible protective effect of milk and dairy product consumption on these conditions. The putative effects of milk and dairy products are possibly mediated through their mineral content of calcium, magnesium, potassium, and vitamin D. These dairy substances exercise their blood pressure-lowering effect either directly on the arterial wall by these minerals or indirectly through blockade of the angiotensin-converting enzyme (ACE) by the amino acids contained in the casein and whey of milk. The blockade of ACE results in the inhibition of production of angiotensin II, a potent vasoconstrictive peptide, and the prevention of degradation of bradykinin, a potent vasodilating peptide. For this concise review, a Medline search of the English language literature was conducted from 2006 to September 2012 and 16 pertinent papers were selected. The potential beneficial pleiotropic effects from these studies together with collateral literature will be discussed in this review.

Mineral content of calcium and magnesium in the serum and longitudinal periodontal progression in Japanese elderly smokers

Evidence from physiological and clinical studies regarding the mechanism by which calcium and magnesium are associated with periodontal disease, adjusted for smoking habits, is lacking. This longitudinal study evaluated the association of serum calcium levels and the calcium/magnesium (Ca/Mg) ratio with periodontal disease progression among smokers and non-smokers. A total of 309 subjects aged 73 years were included. Follow-up surveys were carried out every year for 6 years. After dividing subjects into smokers and non-smokers, multiple logistic regression analysis for men was performed to evaluate the relationship between the serum Ca/Mg ratio and periodontal disease progression. We used the 25th percentile of periodontal disease events for 6 years as the dependent variable and seven other variables, including quartiles for serum Ca/Mg ratios, as independent variables. There was a clear dose-response relationship of Ca/Mg ratio quartiles for periodontal disease events among smokers. Significant differences in odds ratios in the first and second quartiles were seen compared with the fourth quartile (reference): 6.28 (p=0.014) and 5.96 (p=0.022), respectively. However, there was no significant dose-response relationship among non-smokers. A low serum Ca/Mg ratio was significantly associated with periodontal disease progression in Japanese elderly smokers.

Influences of ionic dissolution products of dicalcium silicate coating on osteoblastic proliferation, differentiation and gene expression

This work aims to explore the influence of the ionic products of dicalcium silicate coating on osteoblastic proliferation and differentiation, as well as on the expression of BMP2 and its signal transducers Smad1, 6 and 7 in MG-63 osteoblast-like cells. Plasma-sprayed dicalcium silicate coatings were soaked in DMEM to obtain culture media containing the ionic dissolution products of dicalcium silicate coating (Ca 2SiO 4–DMEM). MG63 osteoblast-like cells were cultured in Ca 2SiO 4–DMEM (experimental group) for 3–12 days, while those cultured in normal DMEM served as control (control group). MTT assay was used to evaluate cell viability and proliferation. Alkaline phosphatase activity (ALP), osteocalcin (OC) and type I collagen (COLI) were investigated as differentiation markers. Gene expression of BMP2 and Smad1, 6, 7 was also detected. BMP2 protein was examined by ELISA assay. Alizarin Red-S (AR-S) assay was used to detect mineralization. The results demonstrated that Si concentration in Ca 2SiO 4–DMEM is markedly higher than that in normal DMEM. Compared to the control group, MG63 cells of the experimental group exhibited upregulated proliferation on day 3, and markedly upregulated gene expression of the differentiation markers, especially on days 9 and 12 for OC and on days 3, 6 and 9 for ALP. Gene expression of BMP2 and Smad1, as well as BMP2 protein secreted into culture media, was also upregulated in the experimental group, while gene expression of Smad6 and 7 was not influenced. AR-S assay indicated a higher calcium mineral content deposition in cells of the experimental group. In conclusion, the ionic products of plasma-sprayed dicalcium silicate coating are beneficial to the proliferation and differentiation of MG63 osteoblast-like cells.

Regulation of Mesenchymal Stem Cell Osteogenic Differentiation by Glucocorticoid-induced Leucine Zipper (GILZ)

Mesenchymal stem cells (MSCs) can differentiate into multiple cell lineages, including osteoblasts and adipocytes. We reported previously that glucocorticoid-induced leucine zipper (GILZ) inhibits peroxisome proliferator-activated receptor gamma-2 (Ppargamma2) expression and blocks adipocyte differentiation. Here we show that overexpression of GILZ in mouse MSCs, but not MC3T3-E1 osteoblasts, increases alkaline phosphatase activity and enhances mineralized bone nodule formation, whereas knockdown of Gilz reduces MSC osteogenic differentiation capacity. Consistent with these observations, real-time reverse transcription-PCR analysis showed that both basal and differentiation-induced transcripts of the lineage commitment gene Runx2/Cbfa1, as well as osteoblast differentiation marker genes including alkaline phosphatase, type I collagen, and osteocalcin, were all increased in GILZ-expressing cells. In contrast, the mRNA levels of adipogenic Ppargamma2 and C/ebpalpha were significantly reduced in GILZ-expressing cells under both osteogenic and adipogenic conditions. Together, our results demonstrate that GILZ functions as a modulator of MSCs and that overexpression of GILZ shifts the balance between osteogenic and adipogenic differentiation of MSCs toward the osteogenic pathway. These data suggest that GILZ may have therapeutic value for stem cell-based therapies of metabolic bone diseases, such as fracture repair.

Element analysis in femur of diabetic osteoporosis model by SRXRF microprobe

Diabetes mellitus affects bone metabolism and leads to osteopenia and osteoporosis, but its pathogenic mechanism remains unknown. To address this problem, mineral element of bone was analyzed in experimental diabetic osteoporosis model. Male Wistar rats were randomly divided into streptozotocin (STZ)-induced diabetic group ( n = 5) and control group ( n = 5). The experiment lasted 68 days and at the end of the experiment, femoral bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry and element content in femur of animals was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe analysis technique. Results showed that femoral BMD in diabetic group was significantly lower than that in control ( P < 0.01). Relative mineral content of calcium (Ca), phosphorus (P) and zinc (Zn) in diabetic femurs decreased significantly compared to controls. And strontium (Sr) in diabetics reduced 11% ( P = 0.09). Relative content of sulfur (S) in average was statistically higher ( P < 0.01) in diabetics than that in controls. But no obvious difference was observed in relative content of chromium (Cr), iron (Fe), copper (Cu), and lead (Pb) between the two groups. Statistical analysis revealed that Ca correlated positively with P ( R = 0.85 and P < 0.001), with Sr ( R = 0.38 and P < 0.05) and with Zn ( R = 0.37 and P < 0.05). Whereas, Zn correlated negatively with S ( R = −0.40 and P < 0.05). Our results reveal that loss of minerals accounts for the BMD reduction in diabetics.

Mineralization of SaOS‐2 cells on enzymatically (silicatein) modified bioactive osteoblast‐stimulating surfaces

There is a demand for novel bioactive supports in surgery, orthopedics, and tissue engineering. The availability of recombinant silica-synthesizing enzyme (silicatein) opens new possibilities for the synthesis of silica-containing bioactive surfaces under ambient conditions that do not damage biomolecules like proteins. Here it is shown that growth of human osteosarcoma SaOS-2 cells on cluster plates precoated with Type 1 collagen is not affected by additional coating of the plates with the recombinant silicatein and incubation with its enzymatic substrate, tetraethoxysilane (TEOS). However, the enzymatic modification of the plates by biosilica deposition on the protein-coated surface caused a marked increase in calcium phosphate formation of SaOS-2 cells as revealed by alizarin red-S staining to quantify calcium mineral content. The increased occurrence of calcium-phosphate nodules on the modified surface was also observed by scanning electron microscopy. These results suggest that by supporting calcium-phosphate deposition in vitro, biosilica (silicatein)-modified surfaces are potentially bioactive in vivo, by stimulating osteoblast mineralization function.

X-Ray Microanalysis of Human Cementum

An energy dispersive x-ray microanalysis study was performed throughout the total length of cementum on five impacted human teeth. Mineral content of calcium, phosphorous, and magnesium were determined with an electron probe from the cemento-enamel junction to the root apex on the external surface of the cementum. The concentration profiles for calcium, phosphorous, and magnesium were compared by using Ca/P and Mg/Ca atomic percent ratio. Our findings demonstrated that the Ca/P ratio at the cemento-enamel junction showed the highest values (1.8-2.2). However, the area corresponding to the acellular extrinsic fiber cementum (AEFC) usually located on the coronal one-third of the root surface showed a Ca/P media value of 1.65. Nevertheless, on the area representing the fulcrum of the root there is an abrupt change in the Ca/P ratio, which decreases to 1.3. Our results revealed that Mg(2+) distribution throughout the length of human cementum reached its maximum Mg/Ca ratio value of 1.3-1.4 at.% around the fulcrum of the root and an average value of 0.03%. A remarkable finding was that the Mg/Ca ratio pattern distribution showed that in the region where the Ca/P ratio showed a decreasing tendency, the Mg/Ca ratio reached its maximum value, showing a negative correlation. In conclusion, this study has established that clear compositional differences exist between AEFC and cellular mixed stratified cementum varieties and adds new knowledge about Mg(2+) distribution and suggests its provocative role regulating human cementum metabolism.

미역취뿌리 추출물이 성장기 흰쥐의 골대사에 미치는 영향

본 연구에서는 3주령의 암컷 흰쥐를 이용하여 미역취뿌리 추출물이 골대사에 미치는 영향을 조사하고자 미역취뿌리 메탄올 추출물을 10, 50, 100 mg/kg/day의 농도로 음용수에 희석하여 9주간 사육시켰다. 매주 체중과 사료효율을 측정한 결과, 대조군에 비해 체중의 변화나 사료효율에는 유의적으로 차이가 없는 것으로 보아 미역취 뿌리 추출물에 대한 기본적 독성은 없고, 성장에 미치는 영향은 없는 것으로 사료되었다. 그리고 3주 간격으로 소변으로 배출되는 Ca과 P의함량을 ICP로 분석 한 결과, 10 mg/kg/day농도로 음용한 군에서 유의적으로 감소됨을 확인 할 수 있었고 혈액으로 유리되는 Ca과 P의 함량 또한 섭취군에서 유의적으로 감소되는 것을 확인하였다. 또한 섭취 후 9주째에 양에너지 방사선 골밀도 측정기(dual energy x-ray absorptiometry, DEXA)를 이용하여 척추, 대퇴골, 골반의 골밀도와 골무기질 함량을 측정한 결과, 메탄을 추출물을 음용한 군의 척추 골밀도가 대조군에 비해 유의적으로 높게 나타났으며, 글 무기질 함량 또한 대퇴골과 골반에서 대조군에 비해 유의적으로 높게 나타났다. 따라서 미역취뿌리 메탄을 추출물의 음용이 암컷 흰쥐에서 골밀도 및 골함량에 유의하게 작용하고 또한 골대사 과정에서 유리되는 Ca와 P의 대사과정에 작용하여 유리되는 Ca과 P의 양을 감소시켜 이상의 결과로 미뤄볼 때, 적절한 미역취뿌리 추출물의 투여는 흰쥐의 성장에 대해 부작용이나 독성없이 골밀도와 골무기질 함량을 높였으며 앞으로 조골세포 기능 저하로 인한 골대사 질환에 사용되어 질 수 있을 것이다. To investigate the bioactivities of Solidago virga-aurea var. gigantea Mig. Root (SVR), we studied the effect of a SVR methanol extract on the activity of bone metabolism. Spraque-Dawley three-week-old female rats were randomly assigned to groups as follows : non-supplemented rats and supplemented with SVR at 10, 50, 100 mg/kg bw/day. Every week determined weight gain and food intake, urine and blood examination of mineral content of calcium and phosphorus was performed each at experimental periods of 3 and 9 weeks respectively; bone mineral density and bone mineral content were also assayed. There were no significant differences in body weight or feed efficiency ratio levels. However, the biological value of calcium and phosphorus excretion in the group supplemented with SVR extract decreased significantly more than that in the group not supplemented with SVR extract. Also, spine BMD, femur BMC and pelvis BMC per weight were significantly greater on SVR extract supplemented groups than that of the control group. In conclusion, it might be expected that methanol extract of SVR does not impair the growth of rats and may improve bone metabolism in rats.

The relation of radionuclide uptake by bone to the rate of calcium mineralization. I: Experimental studies using 45Ca, 32P and 99Tcm-MDP.

The study of the uptake of radionuclides by bone has been undertaken in a mouse tail graft model using 45Ca, 32P and a routine bone scanning agent 99Tcm-MDP, together with serial calcium determinations. The model provided an experimental system in which the calcium mineral content and the rate of mineralization both changed progressively throughout its development. A significant linear correlation was found between 45Ca and 32P uptake and the rate of calcium mineralization, which held for all stages of the graft's growth. Both radiotracers therefore accurately reflected the calcium mineral deposition. In the case of 99Tcm-MDP, the correlation with mineralization rate only applied for the most active growth period of the graft when the rate was increasing. For all radiotracers, the peak in bone uptake corresponded to the maximum in mineralization rate.