Cooling Capacity Test for MIL-101(Cr)/CaCl2 for Adsorption Refrigeration System.

An MIL-101(Cr) powder material was successfully prepared using the hydrothermal synthesis method, and then the original MIL-101(Cr) was combined with different mass fractions of CaCl2 using the immersion method to obtain a MIL-101(Cr)/CaCl2 composite material. The physical properties of the adsorbent were determined by X-ray powder diffraction (XRD), an N2 adsorption desorption isotherm test, and thermogravimetric analysis (TG). The water vapor adsorption performance of the metal-organic frameworks MOFs was tested with a gravimetric water vapor adsorption instrument to analyze its water vapor adsorption mechanism. Based on the SIMULINK platform in the MATLAB software, a simulation model of the coefficient of performance (COP) and cooling capacity of the adsorption refrigeration system was established, and the variation trends of the COP and cooling capacity of the adsorption refrigeration system under different evaporation/condensation/adsorption/desorption temperatures was theoretically studied. MIL101-(Cr)/CaCl2-20% was selected as the adsorption material in the adsorption refrigeration system through the physical characterization of composite materials with different CaCl2 concentrations by means of adsorption water vapor test experiments. A closed adsorption system performance test device was built based on the liquid level method. The cooling power per unit and adsorbent mass (COP and SCP) of the system were tested at different evaporation temperatures (288 K/293 K/298 K); the adsorption temperature was 298 K, the condensation temperature was 308 K, and the desorption temperature was 353 K. The experimental results showed that COP and SCP increased with the increase in the evaporation temperature. When the evaporation temperature was 298 K, the level of COP was 0.172, and the level of SCP was 136.9 W/kg. The COP and SCP of the system were tested at different adsorption temperatures (293 K/298 K/303 K); the evaporation temperature was 288 K, the condensation temperature was 308 K, and the desorption temperature was 353 K. The experimental results showed that the levels of COP and SCP decreased with the increase in the adsorption temperature. When the adsorption temperature was 293 K, the level of COP was 0.18, and the level of SCP was 142.4 W/kg.

Citrate pharmacokinetics and calcium levels during high-flux dialysis with regional citrate anticoagulation.

BACKGROUND: Regional citrate anticoagulation is a very effective anticoagulation method for haemodialysis. However, it is not widely used, primarily due to the risk of hypocalcaemia. We studied citrate and calcium kinetics to better understand safety aspects of this anticoagulation method. METHODS: During 15 haemodialysis treatments with a calcium-free dialysis solution, citrate was infused pre-dialyser and calcium was substituted post-dialyser. Systemic and extracorporeal citrate and calcium concentrations were repeatedly measured to calculate citrate and calcium pharmacokinetics. RESULTS: Removal by dialysis constituted the major elimination pathway of citrate (83 +/- 5%). Systemic citrate load and concentrations were low (17 +/- 7 mmol/4 h, 0.3 +/- 0.15 mmol/l). Combined use of calcium-free dialysate and citrate infusion increased diffusible calcium to 80% of total calcium and induced substantial dialytic loss of calcium (43 +/- 4 mmol/4 h). Since calcium was substituted, systemic calcium balances were positive (approximately +5 mmol) and concentrations stable. Calcium supplementation correlated with calcium dialytic losses, which in turn were dependent on total calcium and haematocrit. CONCLUSIONS: When using calcium-free dialysate during citrate anticoagulation, hypocalcaemia is very likely unless calcium is re-infused, because large amounts of calcium are lost in the dialysate. However, an accumulation of citrate in the patient's systemic circulation is an unlikely cause of hypocalcaemia since most of the citrate is removed by dialysis. Calcium substitution and monitoring are the most important safety measures. We propose a rational approach based on haematocrit and total calcium for the choice of the starting calcium supplementation rate.

Divalent cobalt as a label to study lymphocyte distribution using PET and SPECT.

UNLABELLED: PET and SPECT allow the study of the distribution of lymphocytes in living humans, provided that these cells are adequately prelabeled ex vivo. Such a labeling technique should not only be nontoxic to lymphocytes but it also should take into consideration that their kinetics are such that radioactivity must be followed for at least 24 hr. We describe the potential of divalent cobalt isotopes (55Co2+, half-life 17.5 hr for PET; 57Co2+, half-life 270 days for SPECT) for labeling lymphocytes. METHODS: Isolated rat lymphocytes were incubated with 57CoCl2 with or without unlabeled CoCl2 or CaCl2 carrier or other compounds. In some experiments, the accumulation of radioactive cobalt and calcium in lymphocytes was determined in the presence of phorbol myristate acetate alone, calcimycine alone or in combination. The toxicity of cobalt to lymphocytes was assessed with the trypan blue exclusion test and by assessing their proliferative capacity using radioactive thymidine incorporation as a readout. Biodistribution of cobalt-labeled lymphocytes was determined with postmortem analysis and compared with that of the free (nonlymphocyte-bound) tracer. RESULTS: At high concentrations (more than 100 x necessary for adequate labeling), cobalt was not cytotoxic. Incubation of labeled lymphocytes in tissue culture medium for 24 hr in vitro showed a loss of less than half of the incorporated cobalt radioactivity. Twenty-four hours after in vitro labeling of lymphocytes and intravenous injection, radioactivity accumulated not only in the liver, kidney and bladder of the rat but in the spleen and lungs, which differed from the distribution of the free tracer. Uptake and binding to rat lymphocytes of Co2+ partly mimicked that of Ca2+. The binding of cobalt, however, was stronger and nonsaturable. CONCLUSION: These results warrant further exploration of cobalt as a PET or SPECT label of human lymphocytes.

Biologic mechanisms of 89SrCl2 incorporation into type I collagen during bone mineralization.

UNLABELLED: 89SrCl2 is currently used as a palliative treatment for painful osseous metastases associated with an osteoblastic reaction in bone. However, the underlying biologic mechanism by which 89SrCl2 accumulates at these lesions and mediates palliation remains unclear. The aim of this study was therefore to elucidate this mechanism. METHODS: An in vitro cell biologic model, incorporating the MC3T3-E1 murine osteoblast cell line, was established to replicate the process of collagen production and mineralization. Experiments were performed to investigate the cellular association of 89SrCl2 and 45CaCl2 with both MC3T3-E1 cells and the PC-3 human prostate adenocarcinoma cell line. RESULTS: No evidence of intracellular localization of 89SrCl2 or 45CaCl2 was found for either cell line. Localization of radiolabel was seen to be associated with MC3T3-E1 cells but only in cultures that had undergone both differentiation and mineralization. The association of 89SrCl2 was inhibited by the alkaline phosphatase inhibitor levamisole, and extracellular localization of 89SrCl2 was confirmed by microautoradiography. CONCLUSION: 89SrCl2 acts as a calcium mimic and, as such, becomes associated with the collagen matrix produced by the MC3T3-E1 cells during collagen mineralization.

Effect of magnesium supplementation on the fractional intestinal absorption of 45CaCl2 in women with a low erythrocyte magnesium concentration.

The cosupplementation of magnesium with calcium has been suggested to be beneficial in the prevention of osteoporosis. We investigated the effect of magnesium supplementation on parameters of bone resorption and fractional 45Ca absorption. Twenty apparently healthy women with a mean age of 39.2 +/- 9.2 years and an erythrocyte magnesium concentration less than 1.97 mmol/L were recruited into a controlled magnesium supplementation trial. During weeks 1 to 4, they received a daily control preparation, potassium/sodium citrate malate (PSCM). During weeks 5 to 8, the subjects received magnesium citrate malate (MCM) equivalent to 250 mg magnesium per day. During the fourth and eighth weeks, blood was collected for measurement of the serum intact parathyroid hormone (PTH) concentration and serum and erythrocyte magnesium concentration. Urine was collected for measurement of calcium, magnesium, creatinine, and deoxypyridinoline excretion. On the final day of each treatment period, 5 microCi45CaCl2 was administered orally, and the isotope was traced in the blood and urine over 7 hours. Urinary calcium, 45Ca, and deoxypyridinoline excretion, as well as serum intact PTH levels, showed no statistically significant changes as a result of magnesium supplementation. However, urinary magnesium excretion increased by 31.1% (P < .005) while fractional 45Ca absorption decreased by 23.5% (P < .001) as a result of magnesium supplementation. It is concluded that magnesium supplementation does not result in changes in bone resorption, while the fractional intestinal absorption of 45Ca appears to decrease.

Intracellular calcium accumulation during the evolution of hypoxic-ischemic brain damage in the immature rat.

An excessive intracellular accumulation of calcium (Ca2+) in neurons and glia has been proposed to represent a major 'final common pathway' for cell death arising from hypoxia-ischemia. To clarify the role of altered calcium flux into the perinatal brain undergoing hypoxic-ischemic damage, 7-day postnatal rats underwent unilateral common carotid artery ligation followed by systemic hypoxia with 8% oxygen. This insult is known to produce brain damage in the form of selective neuronal death or infarction largely limited to the cerebral hemisphere ipsilateral to the arterial occlusion. Either prior to or following hypoxia-ischemia, the rat pups received a s.c. injection of 45CaCl2, and specimens of blood, cerebrospinal fluid (CSF), and brain were obtained for isotopic measurements and the calculation of the extent of brain intracellular radioactivity. During hypoxia-ischemia, there was a modest increase in intracellular Ca2+ radioactivity (+28-47%) in both cerebral hemispheres only after 2 h of hypoxia-ischemia. During recovery from 2 h of hypoxia-ischemia, intracellular Ca2+ accumulated progressively only in the ipsilateral cerebral hemisphere for up to 24 h, during which interval intracellular Ca2+ decreased in the contralateral hemisphere. No such progressive accumulation was noted during recovery in animals previously exposed to only 1 h of hypoxia-ischemia. The results suggest that a disruption of intracellular Ca2+ homeostasis is a major contributing factor in the evolution of perinatal hypoxic-ischemic brain damage. Ca2+ accumulation is a relatively modest and late event during the hypoxic-ischemic phase, and a progressive overload occurs during the recovery phase only if infarction occurs. The question remains as to whether or not the intracellular Ca2+ overload occurring during recovery is a contributor to or a consequence of the ultimate brain damage.

Simultaneous measurements of twenty-four-hour whole-body retention of 47Ca-chloride and 99mTc-MDP: early differentiation of metabolic bone diseases in rat models.

The 24-h whole-body retention (24-h WBR) of 47Ca-chloride and 99mTc-MDP was measured in four rat models over a 6-week period at 2 week intervals. Fine detail bone radiographs of the femurs and histologic bone specimens were also obtained simultaneously. In the osteomalacic (M) and steroid-induced osteoporotic (S) groups the 24-h WBR values of 47Ca were significantly lower, and in the osteoporotic (P) group were higher than in the control (C) group from the second week. The 24-h WBR values of 99mTc-MDP were significantly higher in the M group and were lower in the S group from the second week. Simultaneous measurements of 24-h WBR of these two radiopharmaceuticals facilitated the early differentiation of metabolic bone diseases in the animal models prior to the detection of radiologic bone changes.

The effect of a standard oral calcium load given in two different forms on plasma ionized calcium and serum PTH.

A standard dose (1 g, 25.4 mmol) of calcium was administered both as calcium chloride in syrup and as Calcium-Sandoz Syrup (calcium glubionate and calcium galactogluconate) to 10 volunteers. Both dosage forms caused a significant rise in ionized calcium and a significant fall in concentration of serum PTH, the calcium chloride producing significantly greater changes. The urinary excretion of calcium measured over 5 h after calcium chloride was double that after Calcium-Sandoz. Calcium chloride, as expected, also gave rise to a decreased urine pH. Calcium chloride would be the better choice for an oral PTH suppression test.

Improving the delivery of continuous renal replacement therapy using regional citrate anticoagulation.

AIMS: Regional citrate anticoagulation during acute renal replacement therapy (RRT) effectively prevents extracorporeal thrombosis and avoids bleeding risk. There have been a number of citrate anticoagulation protocols published; but a simple and predictable scheme with standardized components and procedures, as well as clearly defined citrate pharmacokinetics, is needed for continuous RRT (CRRT) that is now used frequently in the critical care setting. The present study sets forth methodology with standardized blood flow and dialysate composition, and with citrate and calcium infusions that are quantitatively linked to extracorporeal blood flow rate--a predictable and easily replicated CRRT paradigm. MATERIALS AND METHODS: CRRT using continuous venovenous hemofiltration with dialysis (CVVHD) was standardized using 150-200 ml/min blood flow, calcium-free dialysate with only moderate sodium (135 mEq/l) and bicarbonate (28 mEq/l) concentrations, and ultrafiltration limited to that needed for overall fluid balance in the intensive care unit. Citrate infusion (ACD-A solution) into the extracorporeal blood and calcium repletion in blood returned to the patient were proportional to blood flow. Anticoagulation was accomplished by keeping extracorporeal ionized calcium below 0.4 mM/l. Filter performance, citrate removal and changes in calcium, sodium and alkali were evaluated longitudinally. RESULTS: CVVHD using this protocol delivered urea clearance exceeding 2 l/h (48 l/d) when filter function was sustained. Filter longevity was markedly improved using citrate when compared with standard heparin anticoagulation, and nursing time spent on initiating and troubleshooting CRRT was approximately halved using this protocol. Sieving coefficients for urea, creatinine and citrate were approximately 0.9 and were sustained through nearly 3 days of filter use. Citrate clearance and removal were quantitatively linked to dialysate and ultrafiltration flow, resulting in 35-50% direct removal of the citrate-calcium chelate and reduced systemic citrate load. Serum tonicity and acid-base status were not problematic. The only notable side effect was modest calcium accumulation that necessitated reduction in calcium repletion rate. CONCLUSIONS: CVVHD is well suited to regional citrate anticoagulation. The present protocol is straightforward and predictable, with minor metabolic consequences that can be anticipated and adjusted. These results commend regional citrate anticoagulation to wider application.

Preparation of alginate/chitosan microcapsules and enteric coated granules of mistletoe lectin.

The aqueous extract of European mistletoe (Viscum album, L.) has been used in cancer therapy. The purified mistletoe lectins, main components of mistletoe, have demonstrated cytotoxic and immune-system-stimulating activities. Korean mistletoe (Viscum album L. coloratum), a subspecies of European mistletoe, has also been reported to possess anticancer and immunological activities. A galactose- and N-acetyl-D-galactosamine-specific lectin (Viscum album L. coloratum agglutinin, VCA) with Mr 60 kDa was isolated from Korean mistletoe. Mistletoe preparations have been given subcutaneously due to the low stability of lectin in the gastrointestinal (GI) tract. In the present study, we investigated the possibility of alginate/chitosan microcapsules as a tool for oral delivery of mistletoe lectin. In addition, our strategy has been to develop a system composed of stabilizing cores (granules), which contain mistletoe lectin, extract or powder, coated by a biodegradable polymer wall. Our results indicated that successful incorporation of VCA into alginate/chitosan microcapsules has been achieved and that the alginate/chitosan microcapsule protected the VCA from degradation at acidic pH values. And coating the VCA with polyacrylic polymers, Eudragit, produced outstanding results with ideal release profiles and only minimal losses of cytotoxicity after manufacturing step. The granules prepared with extract or whole plant produced the best results due to the stability in the extract or whole plant during manufacturing process.

Soluble calcium/SMFP dentifrice: effect on enamel fluoride uptake and remineralization.

PURPOSE: To evaluate in situ the effect of soluble calcium on fluoride uptake and remineralization by human dental enamel from a sodium monofluorophosphate (SMFP) dentifrice. MATERIALS AND METHODS: Eight volunteers took part in this cross-over, double-blind design study performed in three phases of 45 days. During each phase of the experiment, the subjects wore an acrylic resin appliance containing four blocks of human dental enamel with artificial caries to evaluate fluoride uptake and remineralization by three dentifrices: SMFP containing CaCl2, SMFP, and placebo. After each phase, the enamel blocks were removed and the total fluoride uptake (ppm F) and microhardness (Knoop) were measured. Statistical analyses (ANOVA and Turkey's test) were done. RESULTS: There was no statistically significant difference between SMFP-CaCl2 and SMFP treatments regarding the amount of fluoride and microhardness data of treated enamel blocks as well as their areas under the curves, although both differed significantly (P < 0.05) when they were compared with placebo. However, the SMFP-CaCl2 treatment demonstrated the highest values on fluoride uptake and microhardness data. Furthermore, the microhardness data demonstrated 50% and 40% of remineralization for SMFP-CaCl2 and SMFP dentifrices, respectively.

[Increased plasma membrane permeability for Ca2+ in radiation-induced thymocyte apoptosis]. / Uvelichenie pronitsaemosti plazmaticheskoi membrany dlia Ca2+ pri radiatsionno-indutsirovannom apoptoze timotsitov.

Parameters of the Ca2+ permeability (the 45Ca influx rate in the presence of orthovanadate blocking the Ca(2+)-ATPhase, and the initial rate of the 45Ca uptake) and the DNA fragmentation were determined in rat thymocytes after gamma-irradiation-induced (with a dose of 5 Gy) apoptosis. Within the first 30-90 min after irradiation, the 45Ca influx rate that is characteristic of the membrane passive permeability remained unchanged. The initial rate of the 45Ca uptake that is characteristic of the Ca2+ exchange almost doubled. In 90-180 min, the rate of the 45Ca influx in the irradiated cells increased 1.5 to 2.0 times. An increase in the DNA fragmentation was observed in 90-120 min after irradiation of thymocytes; in 3 h, it developed up to 50%. Thus, modification of the membrane Ca2+ permeability in the irradiated thymocytes precedes a stage of initiation of the DNA degradation. A degree of disturbance of the membrane passive permeability increases as the thymocyte apoptosis progresses. The obtained data suggest that disturbance of the passive Ca2+ permeability and the intracellular Ca2+ homeostasis are responsible for the apoptosis of lethally irradiated thymocytes.

[Regulation of calcium metabolism in hypertension]. / Reguliatsiia obmena kal'tsiia pri gipertonicheskoi bolezni.

In patients with hypertensive disease, the intravenous calcium tolerance test revealed a delayed elimination of loading hypercalcemia, which totally reflects the effectiveness mechanisms aimed at removing excessive calcium from the extracellular space. In hypertensives, renal calcium excretion was also delayed due to a lower suppression of calcium channel reabsorption. The patients showed a greater background concentration of parathyroid hormone (PTH) and during the calcium tolerance test a much lower PTH levels and higher calcitonin concentrations, though their homeostatic effects remained inadequate due to their diminished sensitivity of target organs. Thus, there was an increase in the activity of parathyroidal glands in patients with hypertensive disease.

Enhanced oral bioavailability of calcium using bovine serum albumin microspheres.

Low oral bioavailability of calcium leads to impairment of calcium homeostasis particularly during the high requirement phases of human growth. The objective of the current study was to prepare microspheres of calcium using bovine serum albumin and assess its viability to enhance the oral bioavailability. Microspheres of calcium were prepared by emulsion chemical cross linking method, characterized, evaluated for in vitro release and in vivo absorption. The prepared microspheres were found to be spherical in shape with smooth surface. High entrapment efficiency (>50%), desired particle size (<10 µm), high zeta potential values (-30.91 ± 3.06 to -34.65 ± 1.01 mV) and low polydispersity indices (0.61 ± 0.04 to 0.88 ± 0.05) were recorded in the prepared microspheres. In vitro release profile suggests that <10% of calcium was discharged in the gastric media (in 30 min) from the microspheres prepared using higher drug/polymer ratio (1:1, formulation F4). The pharmacokinetic data obtained in Sprague-Dawley rats showed that the rate and extent of calcium absorption was significantly enhanced following the administration of microspheres. The serum calcium level profiles indicate that the C(max) and AUC(0-α) were significantly higher (p < 0.001) when calcium was administered from microspheres when compared to control. Rapid absorption of calcium was also observed from microspheres and may be attributed to a greater uptake into intestinal Peyer's patches. Given the excellent results in the in vivo studies, it can be concluded that calcium loaded bovine serum albumin microspheres could be an effective and promising approach for the oral therapy of calcium. Indeed, this approach can be an alternative to parenteral therapy in acute hypocalcaemia as well.

Effects of bleaching agents containing fluoride and calcium on human enamel.

OBJECTIVE: Since little is known about the effects of carbamide peroxide (CP) containing fluoride (F) or calcium (Ca), this study evaluated the effects of experimental and commercially available bleaching agents, with or without F and Ca, on enamel. METHOD AND MATERIALS: Sound enamel slabs were randomly divided into six groups (n = 10): placebo gel (PLA); Whiteness (WHI-10% CP; FGM); Opalescence F (OPA-10% CP+F; Ultradent); Pola Night F (PN-10% CP+F; SDI); and experimental gels: 10% CP + F (CPF) and 10% CP + Ca (CPCa). The samples were submitted to 6-hour gel applications daily for 14 days and stored in remineralizing solution after treatment. Enamel microhardness measurements were performed at baseline and after bleaching. In addition, the analytical concentrations of F and Ca and the pH of the water used to rinse the bleached surface were analyzed by means of ion-selective electrode, atomic absorption spectroscopy, and pH meter, respectively. RESULTS: Enamel surface microhardness significantly decreased after bleaching with nonenhanced 10% CP (WHI). The chemical analyses suggest F uptake promoted by high-concentrate F bleaching gels (CPF, OPA, and PN) and a F loss with nonenhanced 10% CP bleaching gels (PLA, WHI). CP agent enhanced with Ca (CPCa) also caused Ca enamel uptake. CONCLUSION: Enamel was susceptible to mineral changes during bleaching treatment, but mineral loss was minimized by the addition of F and Ca to bleaching agents.

Treatment option for sperm- or oocyte-related fertilization failure: assisted oocyte activation following diagnostic heterologous ICSI.

BACKGROUND: Failed fertilization occurs in 2-3% of ICSI cycles and is mainly due to lack of oocyte activation. Heterologous ICSI of patient's sperm in mouse oocytes allows discrimination between sperm- and oocyte-related aetiologies of activation failure. Assisted oocyte activation (AOA) by Ca-ionophore treatment can initiate fertilization in subsequent therapeutic ICSI. We report on diagnosis and clinical treatment in 17 patients with previously failed fertilization. METHODS: Sperm from patients were injected into mature mouse oocytes. Activation capacity was assessed by 2-cell formation (mouse oocyte activation test, MOAT). When no activation occurred, it was assumed that the spermatozoon was deficient; otherwise an oocyte-related factor was suspected. In a subsequent ICSI cycle, AOA was done by ICSI with CaCl2 followed by a Ca2+ ionophore exposure. Fertilization was checked 16-20 h later. Embryo transfer was on day 2 or 3. RESULTS: MOAT showed sperm-related activation deficiency in six globozoospermic patients and two patients with extreme oligoasthenoteratozoospermia. One patient with small sperm acrosomes had a normal activation percentage. In eight other patients, the MOAT revealed a relatively normal activation capacity of the sperm, indicating an oocyte-related defect. After AOA, fertilization rates were 77 and 71% in the sperm- and oocyte-related groups respectively. Five pregnancies were achieved in the globozoospermia group and three in cases of oocyte-related activation failure. CONCLUSIONS: Assisted oocyte activation enables normal fertilization and pregnancy in sperm- and oocyte-related fertilization failure.

Intestinal absorption of calcium from calcium ascorbate in rats.

The intestinal absorption of calcium (Ca) from Ca ascorbate (Ca-AsA) was investigated in normal rats. Each animal was perorally administered either 5mg (low dose) or 10mg (high dose) of Ca in 1ml of distilled water as Ca-AsA, Ca carbonate (CaCO3), or Ca chloride (CaCl2), which were intrinsically labeled with 45Ca using 45CaCl2. The amount of radioactivity in plasma was measured periodically up to 34h after dosing, and pharmacokinetic parameters were calculated from the radioactivity in plasma. The time taken to reach the maximum 45Ca level (Tmax) did not differ among the three groups. The area under the plasma 45Ca level/time curve (AUCinfinity) value for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups. The radioactivity at Tmax (Cmax) for the Ca-AsA group was significantly higher than those for the CaCO3 and the CaCl2 groups for the low dose, and comparable with or significantly higher than those for the CaCl2 and CaCO3 groups for the high dose. Similar results were observed for whole-body 45Ca retention. Radioactivity in the femur 34h after dosing was the highest in the Ca-AsA group and the lowest in the CaCO3 group. The rank order of solubility in water, the first fluid (pH 1.2, JP-1) of JPXIII disintegration medium, acetate buffer solution (pH 4.0), triethanolamine-malate buffer solution (pH 7.0) and ammonium chloride buffer solution (pH 10.0) at 37 degrees C was CaCl2 > Ca-AsA > CaCO3. In contrast, the rank order of the solubility in the second fluid (pH 6.8, JP-2) of JPXIII disintegration medium at 37 degrees C was Ca-AsA > CaCl2 > CaCO3. These results indicate that the absorbability of Ca from Ca-AsA is almost comparable with, or higher than, that from CaCl2 and significantly higher than that from CaCO3 because of its high degree of solubility in the intestine. Therefore, Ca-AsA would be useful as a Ca supplement with relatively high absorption from intestine.