• International Journal of Oral Biology
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• v.31 no.2
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• pp.53-65
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• 2006

Calcium concentration in the bone resorption lacunae is high and is in the mM concentration range. Both osteoblast and osteoclast have calcium sensing receptor in the cell surface, suggesting the regulatory role of high extracellular calcium in bone metabolism. In vitro, high extracellular calcium stimulated osteoclastogenesis in coculture of mouse osteoblasts and bone marrow cells. Therefore we examined the genes that were commonly regulated by both high extracellular calcium and $1,25(OH)_2vitaminD_3(VD3)$ by using mouse oligo 11 K gene chip. In the presence of 10 mM $[Ca^{2+}]e$ or 10 nM VD3, mouse calvarial osteoblasts and bone marrow cells were co-cultured for 4 days when tartrate resistant acid phosphatase-positive multinucleated cells start to appear. Of 11,000 genes examined, the genes commonly regulated both by high extracellular calcium and by VD3 were as follows; 1) the expression of genes which were osteoclast differentiation markers or were associated with osteoclastogenesis were up-regulated both by high extracellular calcium and by VD3; trap, mmp9, car2, ctsk, ckb, atp6b2, tm7sf4, rab7, 2) several chemokine and chemokine receptor genes such as sdf1, scya2, scyb5, scya6, scya8, scya9, and ccr1 were up-regulated both by high extracellular calcium and by VD3, 3) the genes such as mmp1b, mmp3 and c3 which possibly stimulate bone resorption by osteoclast, were commonly up-regulated, 4) the gene such as c1q and msr2 which were related with macrophage function, were commonly down-regulated, 5) the genes which possibly stimulate osteoblast differentiation and/or mineralization of extracellular matrix, were commonly down-regulated; slc8a1, admr, plod2, lox, fosb, 6) the genes which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were commonly up-regulated; s100a4, npr3, mme, 7) the genes such as calponin 1 and tgfbi which possibly suppress osteoblast differentiation and/or mineralization of extracellular matrix, were up-regulated by high extracellular calcium but were down-regulated by VD3. These results suggest that in coculture condition, both high extracellular calcium and VD3 commonly induce osteoclastogenesis but suppress osteoblast differentiation/mineralization by regulating the expression of related genes.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.604-609
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• 2003

In order to investigate the transfer rate of calcium into rice and the effect of soaking conditions-temperature (20, 30, 40, 50 and $60^{\circ}C$, $X_1$), calcium concentration of soaking solution (0, 250, 500, 750 and 1000 mg/L, $X_2$) and soaking time (5, 10, 15, 20 and 25 min, $X_3$), moisture absorption rate, hardness and calcium content of rice after soaking were analyzed. When the soaking temperature and time were increased the moisture absorption rate also increased (p<0.01). Quadratic and interaction effects on the moisture absorption rate among variables were highly significant, within 5%. The predictive model for moisture absorption rate $(Y_1)$ was as follows: $Y=16.14+0.78X_1+1.24X_3-0.23X_1{^2}+0.14X_2{^2}-0.42X_3X_1-0.38X_3{^2}\;(R^2=0.9123)$. Hardness was decreased as soaking time and temperature increased. Calcium contents of soaked rice increased as temperature, the calcium concentration of soaking solution and soaking time were increased (p<0.01). Also the interactive effect between soaking time and calcium concentration of soaking solution was high. The predictive model for calcium content $(Y_3)$ was as follows: $Y_3=470.80+110.87X_1+123.47X_2+52.29X_3-7.42X_1{^2}-14.87X_2{^2}-9.49X_3X_2-20.57X_3{^2}\;(R^2=0.9840)$. From the results in this study, if adults and children take 400 g of calcium enriched rice with 600 mg/kg and $700{\sim}900\;mg/kg$, respectively, they can expect to take more calcium than the recommended intake without other calcium reinforcing agents.

• Journal of Plant Biology
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• v.39 no.2
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• pp.113-121
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• 1996

The role of Ca2+ on benzyladenine (BA)-induced senescence retardation in mature wheat (Triticum aestivum L.) primary leaves was investigated. When an extracellular calcium chelator, ethylene glycol-bis-($\beta$-aminoethylether)-N, N'-tetraacetic acid (EGTA) together with BA, was applied to senescing leaves for 4 days of dark incubation, the content of chlorophyll and soluble protein decreased rapidly. And, the content of malondialdehyde (MDA), known to be a degradation product of membrane lipids, increased compared with the BA alone control. The BA-EGTA combination also caused the stimulation of protease and RNase activity and a rapid loss of catalase activity owing to the decling of BA effects. In the case of treatment with only intracellular calcium antagonist 3, 4, 5-trimethoxybenzoic acid 8-(diethylamino) octyl ester (TMB-8) without the BA addition, the chlorophyll content at day 4 after dark incubation decreased in paralled with the increasing concentration of the antagonist. In addition, the chlorophyll content at 10-5 M calcium ionophore A23187 treatment in the absence of BA was similar to that of the BA alone treatment. These results suggest that calcium may mediate the retardation effect of BA on leaf senescence by acting as a second messenger and that the calcium input from cell organelles, as well as the calcium inflow from intercellular spaces and cell walls, may be involved in modulating cytosolic calcium levels related to BA action.

• Journal of Korean Society on Water Environment
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• v.31 no.3
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• pp.253-261
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• 2015

The purpose of this study is the efficient biological treatment of highly concentrated nitrate nitrogen by calcium ion control present within the pickling wastewater. In laboratory scale's experiments research was performed using a sequencing batch reactor and the evaluation of denitrification reaction in accordance with the injection condition of calcium ions, the surface properties of microorganisms, and the evaluation of sludge precipitability were performed. Results of the study showed that the denitrification reaction was delayed when injecting more than 600 mg/L of the calcium ion within the denitrification process. In addition, we observed the absorption form of calcium ions absorbed on the surface of microorganisms following an increase in the calcium ion dose. It was found that as the calcium ion dose increased the sludge precipitability also increased continuously and it is judged that a smooth denitrification induction is possible when treating the nitrate nitrogen by the calcium ion control of pickling waste water and the shortening of precipitation time enables a liquid operation to increase the reaction time.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.4
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• pp.237-249
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• 2019

Confirming the direct link between neural circuit activity and animal behavior has been a principal aim of neuroscience. The genetically encoded calcium indicator (GECI), which binds to calcium ions and emits fluorescence visualizing intracellular calcium concentration, enables detection of in vivo neuronal firing activity. Various GECIs have been developed and can be chosen for diverse purposes. These GECI-based signals can be acquired by several tools including two-photon microscopy and microendoscopy for precise or wide imaging at cellular to synaptic levels. In addition, the images from GECI signals can be analyzed with open source codes including constrained non-negative matrix factorization for endoscopy data (CNMF_E) and miniscope 1-photon-based calcium imaging signal extraction pipeline (MIN1PIPE), and considering parameters of the imaged brain regions (e.g., diameter or shape of soma or the resolution of recorded images), the real-time activity of each cell can be acquired and linked with animal behaviors. As a result, GECI signal analysis can be a powerful tool for revealing the functions of neuronal circuits related to specific behaviors.

• Geomechanics and Engineering
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• v.29 no.1
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• pp.79-90
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• 2022

Soybean-urease induced carbonate precipitation (EICP), as an alternative to microbially induced carbonate precipitation (MICP), was employed for soil improvement. Meanwhile, soluble calcium produced from industrial waste carbide slag powder (CSP) via the acid dissolution method was used for the EICP process. The ratio of CSP to the acetic acid solution was optimized to obtain a desirable calcium concentration with an appropriate pH. The calcium solution was then used for the sand columns test, and the engineering properties of the EICP-treated sand, including unconfined compressive strength, permeability, and calcium carbonate content, were evaluated. Results showed that the properties of the biocemented sand using the CSP derived calcium solution were comparable to those using the reagent grade CaCl₂. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses revealed that spherical vaterite crystals were mainly formed when the CSP-derived calcium solution was used. In contrast, spherical calcite crystals were primarily formed as the reagent grade CaCl₂ was used. This study highlighted that it was effective and sustainable to use soluble calcium produced from CSP for the EICP process.

• Nutrition Research and Practice
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• v.6 no.5
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• pp.396-404
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• 2012

The aim of the study was to investigate the inhibitory effects of calcium against intestinal cancer in vitro and in vivo. We first investigated the effects of calcium treatment in HCT116 and HT29 human colon cancer cells. At the concentration range of 0.8-2.4 mM, calcium significantly inhibited cell growth (by 9-29%), attachment (by 12-26%), invasion (by 15-31%), and migration (by 19-61%). An immunofluorescence microscope analysis showed that the treatment with calcium (1.6 mM) for 24 h increased plasma membrane ${\beta}$-catenin but decreased nuclear ${\beta}$-catenin levels in HT29 cells. We then investigated the effect of dietary calcium on intestinal tumorigenesis in $Apc^{Min/+}$ mice. Mice received dietary treatment starting at 6 weeks of age for the consecutive 8 weeks. The basal control diet contained high-fat (20% mixed lipids by weight) and low-calcium (1.4 mg/g diet) to mimic the average Western diet, while the treatment diet contained an enriched level of calcium (5.2 mg calcium/g diet). The dietary calcium treatment decreased the total number of small intestinal tumors (by 31.4%; P < 0.05). The largest decrease was in tumors which were ${\geq}$ 2 mm in diameter, showing a 75.6% inhibition in the small intestinal tumor multiplicity (P < 0.001). Immunohistochemical analysis showed significantly reduced nuclear staining of ${\beta}$-catenin (expressed as nuclear positivity), but increased plasma membrane staining of ${\beta}$-catenin, in the adenomas from the calcium-treated groups in comparison to those from the control group (P < 0.001). These results demonstrate intestinal cancer inhibitory effects of calcium both in human colon cancer cells and $Apc^{Min/+}$ mice. The decreased ${\beta}$-catenin nuclear localization caused by the calcium treatment may contribute to the inhibitory action.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.251-256
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• 2001

This research is focused on an improvement of additional value of high grade limestone. To obtain the basic data of precipitated calcium carbonate(PCC), studies of physical properties of limestone, calcination and hydration characteristics, the characteristics to manufacture quick lime, hydrated lime, ground calcium carbonate and precipitated calcium carbonate were performed. In the carbonation process, formation of rombohedral must be kept under $10^{\circ}C$ for reaction. Although the temperature of reaction of lime milk was limited under $30^{\circ}C$ for a colloidal PCC manufacture, over $50^{\circ}C$ for spindle type PCC. The recommended reaction conditions for colloidal PCC are $20^{\circ}C$ of reaction temperature, 4% of $Ca(OH)_2$ concentration, 1000rpm of stirring rate and 200ml/min of $CO_2$ gas flow rate.

• The Korean Journal of Physiology
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• v.8 no.1
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• pp.67-76
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• 1974

The effect of saponin on the sodium plus potassium activated ATPase activity was studied in the rabbit red cell ghosts and the experiments were also designed to determine the mechanism of action of saponin on the APTase activity. The following results were observed. 1. The ATPase activity of rabbit red cell ghosts is inhibited by low concentration of saponin but increased by high concentration. The activating effect of saponin on the $Na^{+}-K^{+}-ATPase$ activity is inhibited by ouabain but the stimulation of the $Mg^{++}-ATPase$ by high concentration of saponin is not inhibited by ouabain. 2. The activity ratio of $Na^{+}-K^{+}-ATPase$ by high concentration of saponin is decreased by raising the potassium concentration, and is increased by raising the sodium concentration. 3. The ATPase activity is increased by small amounts of calcium but inhibited by larger amounts. The activity ratio of the enzyme by saponin is decreased by raising the calcium concertration 4. The action on the ATPase activity was not related to the amino group of lysine, the hydroxyl group of threonine, the imidazole group of histidine, or the carboxyl group of aspartic acid. 5. The action of saponin on the ATPase activity is due to sulfhydryl group of the enzyme of $Na^{+}-K^{+}-ATPase$.

• The Korean Journal of Physiology
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• v.12 no.1_2
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• pp.15-23
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• 1978

The action of ascorbic acid on the sodium Plus potassium activated ATPase activity in the rabbit red cell membrane has been investigated and the experiments were also designed to determine the mechanism of action if ascorbic acid on the ATPase activity The following results were observed. 1. The activity of the NaK ATPase from red cell membrane is stimulated by ascorbic acid and the concentration of ascorbic acid for maximal activity is about 8 mM. 2. The activating effect of ascorbic acid on the ATPase activaty, with a given concentration of sodium in the medium, is increased by raisins the potassium concentration but activity ratio is decreased. 3. The activating effect of ascorbic acid on the ATPase activity, with a given concentration of potassium in the medium, is increased by raising the sodium concentration but activity ratio is decreased. 4. The action of ascorbic acid on the ATPase activity is stimulated by calcium ions and activity ratio is increased by raising the calcium concentration. 5. The activating effect of ascorbic acid on the ATPase activity was not related to the sulfhydryl group of cysteine or the hydroxyl group of threonine. 6. The activating effect of ascorbic acid on the ATPase activity is due to amino group and carboxyl group of the enzyme of NaK ATPase.