• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.2
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• pp.352-367
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• 1998

Intracellular pH (pHi) plays an important role in the regulation of cellular processes by influencing the acitivity of various enzymes in cells. Therefore, almost every type of mammalian cell possesses an ability to regulate its pHi. One of the most prominent mechanisms in the regulation of pHi is $Na^+/H^+$ exchanger. This exchanger has been known to be activated when cells are stimulated by the binding of agonist to the muscarinic receptors. Therefore, the aims of this study were to compare the rates of $H^+$ extrusion through $Na^+/H^+$ exchanger before and during muscarinic stimulation and to investigate the possible existence of $HCO_3^-$ transporter which is responsible for the continuous supply of $HCO_3^-$ ion to saliva. Acinar cells were isolated from the rat mandibular salivary glands and loaded with pH-sensitive fluoroprobe, 2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF), for 30min at room temperature. Cells were attached onto the coverglass in the perfusion chamber and the changes in pHi were measured on the iverted microscope using spectrofluorometer. 1. By switching the perfusate from $HCO_3^-$-free to $HCO_3^-$-buffered solution, pHi decreased by $0.39{\pm}0.02$ pH units followed by a slow increase at an initial rate of $0.04{\pm}0.007$ pH units/min. The rate of pHi increase was reduced to $0.01{\pm}0.002$ pH units/min by the simultaneous addition of 1 mM amiloride and $100{\mu}M$ DIDS. 2. An addition and removal of $NH_4^+$ caused a decrease in pHi which was followed by an increase in pHi. The increase of pHi was almost completely blocked by 1mM amiloride in $HCO_3^-$-free perfusate which implied that the pHi increase was entired dependent on the activation of $Na^+/H^+$ exchanger in $HCO_3^-$-free condition. 3. An addition of $10{\mu}M$ carbachol increased the initial rate of pHi recovery from $0.16{\pm}0.01$ pH units/min to $0.28{\pm}0.03pH$ units/min. 4. The initial rate of pHi decrease induced by 1mM amiloride was also increased by the exposure of the acinar cells to $10{\mu}M$ carbachol ($0.06{\pm}0.008pH$ unit/min) compared with that obtained before carbachol stimulation ($0.03{\pm}0.004pH$ unit/min). 5. The intracellular buffering capacity ${\beta}1$ was $14.31{\pm}1.82$ at pHi 7.2-7.4 and ${\beta}1$ increased as pHi decreased. 6. The rate of $H^+$ extrusion through $Na^+/H^+$ exchanger was greatly enhanced by the stimulation of the cells with $10{\mu}M$ carbachol and there was an alkaline shift in the activity of the exchanger. 7. An intrusion mechanism of $HCO_3^-$ was identified in rat mandibular salivary acinar cells. Taken all together, I observed 3-fold increase in $Na^+/H^+$ exchanger by the stimulation of the acinar cells with $10{\mu}M$ carbachol at pH 7.25. In addition, I have found an additional mechanism for the regulation of pHi which transported $HCO_3^-$ into the cells.

• Journal of the Korean Society of Food Culture
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• v.23 no.4
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• pp.507-513
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• 2008

The development of soy cutlets containing textured soy protein (TSP) as a meat analog was studied. In order to decrease the beany flavor and to increase the texture, TSP was treated with 0.3% Flavourzyme or 0.1% Protamex for 10 or 20 min, respectively. The degree of hydrolysis for TSP treated with Protamex was higher than that treated with Flavourzyme. Hydrolysis was observed to increase as the reaction time was increased for both Flavourzyme and Protamex. The water holding capacity of TSP treated with Protamex for 10 min was the highest, and that treated with Flavourzyme for 20 min was similar to that of Protamex treatment for 20 min. The oil binding capacity of TSP treated with Protamex for 20 min was the highest. The hardness of the soy cutlets using TSP treated with Flavourzyme for 10 min was higher than that treated for 20 min, while that of Protamex treated for 20 min was higher than that treated for 10 min. The cohesiveness of the soy cutlets using TSP treated with Flavourzyme or Protamex for 10 min was higher than those treated for 20 min. The chewiness of the soy cutlets treated with Flavourzyme for 10 min was higher than for those treated for 20 min, while those treated with Protamex for 20 min was higher than those treated for 10 min. The springiness of TSP treated with Flavourzyme for 20 min was higher than those treated for 10 min, and higher than those treated with Protamex for 10 or 20 min. For sensory evaluation, the beany flavor of the soy cutlets treated with Protamex for 20 min was the weakest. The flavor and chewiness of both a pork cutlet and a soy cutlet treated with Protamex for 20 min were the best. In the overall quality, soy cutlets treated with Protamex for 20 min was the most desirable. In conclusion, soy cutlets treated with 0.1% Protamex for 20 min could be a reasonable substitute of pork cutlets.

• Animal Bioscience
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• v.35 no.12
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• pp.1921-1928
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• 2022

Objective: This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. Methods: A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Results: Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. Conclusion: These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.169-178
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• 2008

Purpose: The purpose of this study was to determine the efficacy of early low-dose iron supplementation in term breast-fed infants. Methods: Eighty-seven healthy term infants were divided into 3 groups: A, formula-fed; B, breast-fed only; S, breast-fed with iron supplementation (5 mg/day from 2 months of age). We measured ferritin, iron, total iron binding capacity (TIBC), transferrin saturation rate (TFSAT), hemoglobin (Hb), hematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and red cell distribution width (RDW) at birth, 6 months of age, and 12 months of age. Results: 1) At 6 months of age, ferritin, iron, TFSAT, and Hb in Group B were the lowest among the 3 groups, whereas TIBC and RDW were the highest. The incidences of iron deficiency (ID) and iron deficiency anemia (IDA) in Group B were 33% and 30%, respectively, significantly higher than those seen in Groups A (5% and 8%, respectively) and S (7% and 5%, respectively). 2) At 12 months of age, ferritin, TFSAT, Hb, MCV, and MCH in Group B were the lowest among the 3 groups, whereas TIBC and RDW were the highest. Iron and Hct did not differ among the 3 groups. The incidences of ID and IDA in Group B were 64% and 50%, respectively, again significantly higher than those seen in Groups A (4% and 3%, respectively) and S (9% and 7%, respectively). Conclusion: The prevalences of ID and IDA were higher in breast-fed infants than in formula-fed infants, even at 6 months of age. Early and low-dose iron supplementation in breast-fed infants improved iron status and lowered the incidence of iron deficiency anemia in early infancy.

• Korean Journal of Community Nutrition
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• v.9 no.5
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• pp.589-596
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• 2004

This study was performed to investigate the anthropometric data, serum profiles, and nutrient intakes of high school students who are living in Seoul. Anthropometric data showed that mean height and weight were 174.1 cm and 66.6 kg in 99 male and 161.4 cm and 54.0 kg in 116 female students. Mean BMl for male and female students were 21.9 and 22.3 kg/$m^2$, and subjects with BMI > 25 kg/$m^2$ were 14 and 7%, respectively. Total cholesterol, HDL- and LDL-cholesterol of subjects were 149.6$\pm 3.1,\; 46.4 \pm 1.3,\; 86.4 \pm 2.3$,/TEX> mg/dl for males and 169.2 $\pm 3.1,\;50.7 \pm 1.0,\; 100.9 \pm 2.7 mg/dl$ for females, respectively. Hemoglobin (Hb) and total iron binding capacity (TIBC) were 12.8 $\pm 0.1 g/dl, \;437.3 \pm 7.2\mug/dl\; in\; male\; and\; 11.9 \pm 0.1 g/dl,\; 439.4 \pm 5.7\mug/dl$ in female, respectively. Based on Hb classification, 45.6% of male and 45.0% of female students fell into anemic condition. Intakes of energy, Ca, Fe, Zn, riboflavin, and folate were below the Korean RDA. In particular Ca (male and female, respectively, 64.6 and 64.3% RDA) and Fe (male and female, respectively, 78.6 and 64.3% RDA) intakes were extremely low. Serum triglyceride was positively significantly correlated with weight (r =0.22), BMI (r =0.279), waist circumference (WC, r =0.235), triceps skin-fold thickness (TSF, r =0.197) and obesity index (OI, r =0.279). Hb concentration was positively correlated with height (r + 0.387), weight (r =0.349), BMI (r =0.191) and waistlhip ratio (WHR, r =0.380). As for the correlation between serum profiles and nutrient intakes, the Hb concentration was positively correlated with energy (r =0.163), protein (r =0.149), Na (r =0.153), vitamin A (r =0.165), thiamin (r =0.201) and niacin (r =0.192, p < 0.01). These result suggest that the prevalence of Ca and Fe deficiency of student is high and dietary guideline for prevent anemia in this age needs to contain the adequate intake of energy and its related vitamins.