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C Igarashi

Publications and source records attributed to C Igarashi.

10 recordsLinked to original sources
PubMed1995

Bioavailability of calcium from calcium carbonate, DL-calcium lactate, L-calcium lactate and powdered oyster shell calcium in vitamin D-deficient or -replete rats.

The bioavailability of calcium from various calcium sources in humans and animals has been the subject of investigation for many years and there is considerable controversy as to the relative bioavailability of different calcium salts. Most of the studies have used a calcium balance technique which has numerous problems in terms of performance and interpretation. Using a method for evaluating the efficacy of calcium from calcium salts used for plasma calcium metabolism and bone mineralization, we examined the bioavailability of calcium from four commercially available calcium salts, namely calcium carbonate, DL-calcium lactate, L-calcium lactate and powdered oyster shell-calcium in vitamin D-deficient or -replete rats. Among the calcium salts, the differences in bioavailability were small and not statistically significant as tested by analysis of variance in both groups of rats. Thus, we conclude that calcium is utilized to the same extent from calcium carbonate, DL-calcium lactate, L-calcium lactate and powered oyster shell-calcium in both vitamin D-deficient and -replete rats.

Animals↗
PubMed1994

WBN/Kob rat: a new model of spontaneous diabetes, osteopenia and systemic hemosiderin deposition.

A long-term investigation of bone mineral metabolism in a newly developed strain, the WBN/Kob rat, which spontaneously develops diabetes, possibly due in part to hemosiderin deposition, was conducted. WBN/Kob rats used in this study developed diabetes after 9 months of age. Bone mass peaked at 6 months or 8 months of age, and femoral breaking strength was maximal at 8 months of age, declining rapidly after the development of diabetes. In contrast, both the bone mass and the mechanical strength increased up to 14 months of age in controls. The serum osteocalcin (BGP) levels were lower at 4 months of age and serum 1.25(OH)2D levels were significantly lower throughout the study in WBN/Kob rats than in controls. These results suggest that abnormal bone and mineral metabolism is present in WBN/Kob rats before the onset of diabetes, and that bone strength and BMD decrease simultaneously with the development of diabetes. This strain can serve as a useful model, not only of hemosiderosis and diabetes, but also of osteopenia.

Absorptiometry, Photon↗
PubMed1993

The effect of casein phosphopeptides on calcium utilization in young ovariectomized rats.

The effect of casein phosphopeptides (CPPs) on Ca utilization in ovariectomized (OVX) rats was studied. A mixture of CPPs corresponding to the amino acid sequences 1-25 and 1-28 in the beta-casein was isolated from the tryptic digest of beta-casein (beta CPP). After being fed a low Ca diet for 30 days, OVX rats were fed experimental diets of which the Ca level was 0.1%, 0.3% or 0.5% with or without 0.15% beta CPP for 28 days. During days 1-3 of the Ca refeeding period, rats fed beta CPP with 0.5% Ca showed a higher Ca absorption than control rats not supplemented with beta CPP. During days 7-9 and 26-28, there were no significant differences in Ca and P balances between the beta CPP group and the control group for each dietary Ca level. Femoral Ca and P contents from rats fed beta CPP tended to be higher than those from control rats. These results suggest that beta CPP supplementation could have an effect on Ca absorption at a certain degree of Ca deficiency.

Absorption↗
PubMed1991

Stimulation by 1,25-dihydroxyvitamin D3 of in vitro mineralization induced by osteoblast-like MC3T3-E1 cells.

Although vitamin D is essential for mineralization of bone, it is as yet unclear whether vitamin D has a direct stimulatory effect on the bone mineralization process. In the present study, the effect of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on in vitro mineralization mediated by osteoblast-like MC3T3-E1 cells was examined. MC3T3-E1 cells continued to grow after they reached confluency, and DNA content and alkaline phosphatase activity increased linearly until about 16 days of culture, whereas 45Ca accumulation into cell and matrix layer remained low. After this period, DNA content plateaued, and 45Ca accumulation increased sharply. Histological examination by von Kossa staining revealed that calcium was accumulated into extracellular matrix. In addition, needle-shaped mineral crystals similar to hydroxyapatite crystals could be demonstrated in between collagen fibrils by electron microscopy. Thus, MC3T3-E1 cells differentiate in vitro into cells with osteoblastic phenotype and exhibit mineralization. When MC3T3-E1 cells were treated with 1,25(OH)2D3 at this stage of culture, there was a dose-dependent stimulation of 45Ca accumulation by 1,25(OH)2D3, and a significant stimulation of 45Ca accumulation was observed with 3 x 10(-10) M 1,25(OH)2D3. Although 1,25(OH)2D3 enhanced alkaline phosphatase activity and collagen synthesis at the early phase of culture, it did not affect any of these parameters at the late phase when 1,25(OH)2D3 stimulated mineralization. Neither 24,25-dihydroxyvitamin D3 nor human PTH(1-34) affected mineralization in the presence or absence of 1,25(OH)2D3. These results demonstrate that 1,25(OH)2D3 stimulates matrix mineralization induced by osteoblastic MC3T3-E1 cells, and are consistent with the possibility that 1,25(OH)2D3 has a direct stimulatory effect on bone mineralization process.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1984

Heparan sulfate and dermatan sulfate from the liver of a patient with Hurler syndrome: high performance liquid chromatography of their degradation products after incubation with alpha-L-iduronidase-deficient fibroblasts.

Using a high performance liquid chromatography method, degradation products of heparan sulfate (HS) and dermatan sulfate (DS) were investigated after incubation of control and alpha-L-iduronidase-deficient fibroblasts with HS or DS. Characteristic elution profiles of the degradation products were obtained from the respective alpha-L-iduronidase-deficient fibroblasts. Moreover, alpha-L-iduronidase in control fibroblasts was resolved into two distinct components, forms A and B, on DEAE-cellulose column chromatography. Form A alpha-L-iduronidase could degrade HS, but not DS. Conversely, form B alpha-L-iduronidase could not degrade HS, but could degrade DS.

Chondroitin↗
PubMed1983

Characterization of keratan sulfate isolated from liver affected by Morquio syndrome.

Chemical structures of keratan sulfate (KS) isolated from the liver affected by Morquio syndrome type A (classical type) were investigated. In the KS from Morquio syndrome liver, the molar ratios of hexose, total sulfate, N-sulfate and sialic acid to hexosamine were 5.07, 0.90, 0.18 and 0.08, respectively, and about 10% of hexosamine consisted of galactosamine. The KS resulted in a production of oligosaccharides of relatively larger size after digestion with keratanase, as compared with bovine corneal KS. These findings strongly suggest that KS accumulated in the liver affected by Morquio syndrome may be derived from bony KS.

Animals↗
PubMed1969

[Aplastic anemia].

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Anemia, Aplastic↗