• Journal of Nutrition and Health
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• 제29권6호
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• pp.578-589
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• 1996

This study was performed to invstigate the effect of dietary protein level and source on cadmium intoxicification in rats. Forty-eight male rats of Sprague-Dawley strain weighing 171$\pm$3g were blocked into 8 groups of 6 animals according to body weigth, and were raised for 30days. Eight experimental diets different with cadmium(0ppm, 400ppm)and protein(15%, 40%) levels and protein source[casien, I.S.P.(isolated soy protein)] were given to animals for 30days. Food intake, weight gain, food efficiency ratio, liver weight, kidney weight and femur weight were lower in cadmium added group, and higher in high protein groups(40% protein) than medium protein groups(15% protein). But, dietary protein source had no influence on them. Cadmium concerntration of liver was higher in rats fed casein than I.S.P. groups, and cadmium concentration in intestine was higher in high protein groups. In femur both high protein and I.S.P.diets increased cadmium concentrations. MT concdentrations in liver, kidney and intestine were higher in cadmium added group, and kidney intestine MT concentration were higher in high protein group. Absorption and retention rates of cadmium were lower in rat fed I.S.P. than animal fed casein among medium protein groups and cadmium concentration in blood and liver of I.S.P groups were lower than casein groups. But absorption and retention rates of cadmium were similar in high casein and I.S.P. groups. Renal damage by cadmium administration was not seen in all groups. Absorption rates of zinc and copper competing with cadmium in absorption process were lower in high protein groups than medium protein groups and lower in rats fed I.S.P. than casein. In conclusion, weight gain, F.E.R, and MT concentraion of high protein groups were higher than those of medium protein groups and absorption and retention rates of cadmium were lower in high protein groups. From these results, it was shown that cadmium toxicity was alleviated by high dietary protein. Meanwhile, the effect of dietary source on the cadmium toxicity was different with protein level. In medium protein groups absorption and retention rates of cadmium were much lower in rats fed I.S.P. than casein. In high protein groups, cadmium toxicity was not influenced by protein source and absorption and retention rates of cadmium were not different between casein and I.S.P. groups.

• Journal of Nutrition and Health
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• 제1권2호
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• pp.61-85
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• 1968

The experiment was carried out on eight healthy male subjects of 19-22 years old and they were maintained The experiment was carried out on eight healthy male subjects of 19-22 years old and they were maintained under the rice diet, the general mixed diet and the high animal protein diet for 7 days of each experimental period, respectively. The composition of each diet was indicated in Table 3. The allowance' of each nutrient per head per day in each diet were as follows. a) In the rice diet; protein:139.5 g (animal source:64.6 g, vegetable source:74.9 g), fat:25.3 g (animal source:11.3 g, vegetable source:14.0 g), carbohydrate: 644.0 g, calcium:982.3 mg, phosphorus: 2369.2mg, thiamine:2.1 mg, riboflavin: 1.6 mg, and 3211 Cal. b) In the general mixed diet; protein: 97.4g (animal source: 10.5 g, vegetable source: 86.9 g), fat:40.3 g (animal source:7.1 g, vegetable source:33.2 g), carbohydrate:620.7 g, calcium:887.1m g, phosphorus:2200.8m g, thiamine: 1.8m g, riboflavin:1.9m g, and 3158 Cal. c) In the high animal protein diet; protein: 135.6 g (animal source:68.8 g, vegetable source:66.8 g), fat:32.5g (animal source:17.9 g, vegetable source:14.6 g), carbohydrate:930.9 g, calcium: 626.0 mg, phosphorus: 1998.9 mg, thiamine: 1.5 mg, riboflavin: 1.5 mg, and 3194 Cal. The absorption rates of protein, fat, carbohydrate, calcium, phospherus, thiamine and riboflavin in each diet were observed. The results obtained were summarized as follows: 1. The absorption rates of protein and fat in the rice diet were 88.t % and 71.3.%. 2. The absorption rates of protein and fat in the general mixed diet were 83.4% and 86.4%. 3. The absorption rates of protein and fat in the high animal protein diet were 86.8% and 82.4%. 4. The nitrogen balances in the rice, the general mixed and the high animal protein diet groups were +5.7g, +2.3g and +4.0g respectively. 5. The absorption rates of carbohydrate in each diet were all above 95 % and so seemed to be almost completely absorbed except the cellulose in the diets. 6. The calory utilization rates in each diet were all above 93 %. 7. The minimum absorption rates of protein, fat and calory were 83.8%, 63.3%, and 89.7% in the rice diet, 80.0%, 80.9% and 85.9%, in the general mixed diet and 83.6%, 75.7% and. 89.3 % in the high animal protein diet respectively. Therefore, it is assumed that these data might be significant in practical use. 8. The protein absorption rates of the rice diet (88.1 %) was better than that of the general mixed diet (83.4 %). 9. The fat absorption rates of the general mixed diet and the high animal protein diet (86.4% and 82.4%) were signficantly better than that of the rice diet (71.3%). 10. The calcium absorption rates of each diet, rice diet, the general mixed diet and the high animal protein diet were 41.6%, 36.0%, and 27.7%, respectively. 11. The phosphorus absorption rates of each diet were 51.4%, 56.0% and 52.3%, respectively.12. The phosphorus absorption rate seemed better than that of calcium. 13. The thiamine absorption rates of each diet seemed 27.0 %, 42.9 % and 29.5 %, respectively. 14. The riboflavin absorption rates of each diet seemed above 30.6%, 27.1%, and 39.3% respectively. 15. The excretion amounts of thiamine or riboflavin were much more than the amounts ingested of the both vitamins. Therefore, the certain amount of both vitamins seemed to synthesize in the intestine.

• Journal of Photoscience
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• 제2권1호
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• pp.19-25
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• 1995

Picosecond time-resolved and static protein fluorescence spectra and absorption spectra of octopus rhodopsin, a photorecepting protein, are measured and compared with those of bacteriorhodopsin, a photon-induced proton pumping protein, to understand the protein conformations and functions of octopus rhodopsin and its deprotonated photocycle intermediate. The bluer and weaker absorption of retinal indicates that octopus rhodopsin is better in thermal noise suppression but less efficient in light harvesting than bacteriorhodopsin. The protein fluorescence of octopus rhodopsin shows the characteristic of Trp only and the uantum efficiency and lifetime variations may result primarily from variations in the coupling strength with the retinal. The stronger intensity by four times and larger red shift by 12 nm of fluorescence suggest that octopus rhodopsin has more open and looser structure compared with bacteriorhodopsin. Fluorescence decay profiles reveal two decay components of 300 ps (60%) and 2 ns (40%). The deprotonation of protonated Schiff's base increases the shorter decay time to 500 ps and enhances the fluorescence intensity by 20%. The fluorescence and its decay time from Trp residues near retinal are influenced more by the deprotonation. The increase of fluorescence intimates that protein structure becomes loosened and relaxed further by the deprotonation of protonated Schiff's base. The driving force of sequential changes initiated by absorption of a photon is too exhausted after the deprotonation to return the intermediate to the ground state of the begun rhodopsin form.

• The Journal of the Acoustical Society of Korea
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• 제21권3E호
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• pp.126-131
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• 2002

Ultrasonic measurements are made in egg white to study the properties of the solution of the natural protein. The high-Q ultrasonic resonator method is used to get the ultrasonic absorption spectra over the range 0.2-10 ㎒ at 20℃. It is proportional to the 1.25th power of the frequency. The gelation process caused by heat is studied from the change in the velocity and the absorption. at 3 ㎒ using the pulse echo overlap technique over the range of 10-80℃. The absorption decreases with increasing temperature up to 60℃ where it turns up sharply and rapidly increases thereafter. The strong absorption in the gel region is described by the interaction between the solution and the network structure made of protein. Very slow variation in time elapse is observed after the temperature is quickly raised. It would be a real-time observation of the network building process and the characteristic time for the process is shown to be 400 min. A hysteresis phenomenon with respect to the temperature is observed. This phenomenon is associated with the memorizing effect of the network structure of protein of the gel.

• Journal of Nutrition and Health
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• 제27권5호
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• pp.451-459
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• 1994

This study was performed to investigate the effect of sources of protein on iron bioavailability in 10 healthy young Korean women. The 18-day metabolic study consisted of a 6-day adaptation period, 6-day moderate protein(60g protein/day, 18mg Fe/day) and 6-day high protein period(90g protein/day, 18mg Fe/day). During the moderate and high protein period, 5 subjects were fed the high plant protein meals(80% plant protein). Fecal excretion of dietary iron was significantly higher(p<0.05) in high protein high plant diet group(HPP, 9.48$\pm$1.61mg/day) than in high protein high animal diet group (HPA, 14.40$\pm$0.89mg/day). Apparent absorption and bioavailability of iron was also significantly higher(p<0.10) in HPA(40.7$\pm$5.3%, 6.46$\pm$1.61mg/day) than in HPP(14.4$\pm$5.3%, 2.39$\pm$0.89mg/day). But there was no significant difference between the high animal protein group and high plant protein group in moderate protein period. Serum iron concentration and transferrin saturation increased as animal protein intake increased, from 106.0$\pm$5.1ug/이 and 30.6$\pm$1.5% for MPA to 129.1$\pm$6.7ug/이 and 37.1$\pm$1.3% for HPA. Statistically positive correlations were shown not only between the level of dietary heme iron and apparent absorption(r=0.95, p<0.05), but also between serum iron concentration and apparent absorption(r=0.64, p<0.05). Negative iron balance was shown in two subjects fed the moderate protein meals. These results suggest that recommanded dietary allowances of iron may be under the need to maintain the positive balance, and iron bioavaliability increase by only high level of animal protein intake.

• Journal of Nutrition and Health
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• 제22권6호
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• pp.516-530
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• 1989

A 44-day metabolic study was conducted to compare the effects of soy protein and meat protein on N, Ca, P, and Mg metabolism in young Korean males. Meat protein diet(MPD) and soy protin diet(SPD) were provided for 3 weeks each. For MPD, meat protein Supplied 50.3% of total protein and mean daily suplies of Ca, P, and Mg were 33.28mg, 1013.01mg, 226.81mg respectively. For SPD, soy protein supplied 51.8% of total protein and mean contents of Ca, P and Mg were 737.86mg, 1261.76mg, and 451.3mg. Mean daily fecal and urinary excretions of Ca were 350.6mg and 113.3mg for MPD and 515.0mg and 118.3mg for SPD. Apparent absorption rates in MPD and SPD were 4.2mg in MPD and 700.4mg and 475.1mg SPD. Apparent absorption rates were 65.6% in MPD and 44.5% in SPD(p<0.01). For Mg, fecal and urinary excretions were 144.8mg and 81.2mg in MPD and 292.4mg and 65.5mg in SPD. Apparent absorption rates were 37.5% in MPD and 35.2% in SPD. The correlations between urinary Ca, P, and their balance were significant (p<0.001) in MPD, but not in SPD. Urinary Ca was significantly correlated with urinary N, P, Mg(p<0.001) in MPD, but not in SPD. From these results, meat protein seems to increase the excretions of major minerals compared to soy protein.

• Archives of Pharmacal Research
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• 제25권5호
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• pp.572-584
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• 2002

Rapid development in molecular biology and recent advancement in recombinant technology increase identification and commercialization of potential protein drugs. Traditional forms of administrations for the peptide and protein drugs often rely on their parenteral injection, since the bioavailability of these therapeutic agents is poor when administered nonparenterally. Tremendous efforts by numerous investigators in the world have been put to improve protein formulations and as a result, a few successful formulations have been developed including sustained-release human growth hormone. For a promising protein delivery technology, efficacy and safety are the first requirement to meet. However, these systems still require periodic injection and increase the incidence of patient compliance. The development of an oral dosage form that improves the absorption of peptide and especially protein drugs is the most desirable formulation but one of the greatest challenges in the pharmaceutical field. The major barriers to developing oral formulations for peptides and proteins are metabolic enzymes and impermeable mucosal tissues in the intestine. Furthermore, chemical and conformational instability of protein drugs is not a small issue in protein pharmaceuticals. Conventional pharmaceutical approaches to address these barriers, which have been successful with traditional organic drug molecules, have not been effective for peptide and protein formulations. It is likely that effective oral formulations for peptides and proteins will remain highly compound specific. A number of innovative oral drug delivery approaches have been recently developed, including the drug entrapment within small vesicles or their passage through the intestinal paracellular pathway. This review provides a summary of the novel approaches currently in progress in the protein oral delivery followed by factors affecting protein oral absorption.

• 한국식품영양과학회지
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• 제12권3호
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• pp.251-258
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• 1983

엽농축단백질(葉濃縮蛋白質)(LPC)을 이용해서 인공유(人工乳)를 만들 수 있는 기틀을 마련코저, 엽농축단백질(葉濃縮蛋白質)의 기능적(機能的) 성질(性質)을 milk casein 수준으로 높이기 위해 섬바디(Dystaenia takeshimana Nakai) 잎에서 추출한 chloroplastic protein과 cytoplasmic protein 및 Italian ryegrass(Lolium multiflorum Lamb.)에서 추출(抽出)한 엽농축단백질(葉濃縮蛋白質) 1g당 succinic anhydride 0. 10, 0. 25, 100g씩을 가(加)해 숙시닐화시켜 기능성을 조사한 결과는 다음과 같다. 1. bulk density는 섬바디잎에서 추출한 chloroplastic protein 및 cytoplasmic protein과 Italian ryegrass에서 추출한 LPC가 succinic anhydride의 무처리구에서 높았으며 숙시닐화 시킴으로 감소한 후 숙시닐화가 증가하므로서 bulk density는 어느 정도 증가하는 추세였다. 2. 용해도는 숙시닐화를 시킨 각 구에서는 Italian ryegrass LPC 1g에 succinic anhydride 1g 첨가반응시 섬바디 chloroplastic protein에서는 시료 1g당 succinic anhydride 0.1g이상 첨가반응시 milk casein 보다 용해도가 높은 경향이었다. 3. 흡수도 및 지방흡착에서는 숙시닐화 시킨 것과 시키지 않은 것 모두가 milk casein 보다 높은 경향이었다. 4. 유화능과 유제의 안정성에서는 숙시닐화를 시키지 않은 각(各) LPC가 약간 낮은 반면 숙시닐화 시킴에 따라 milk casein 보다도 높고 점점 증가하는 경향이었다.

• Journal of Nutrition and Health
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• 제21권1호
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• pp.47-60
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• 1988

This study was performed to investigate the effect of dietary levels on protein metabolism in eight healthy Korean adult females. The 20-day metabolic study consisted of 2 day adaptation period and three 6-day experimental. Three experimental diets were low protein (LP : protein 44g), high protein(HP : protein 85g) and high animal protein (HAP : protein-84g). The apparent absorption and balance on nitrogen were significantly higher in high protein than in low protein diet. Nitrogen, absorption rate was about 75% for low protein and about 85% for high protein intake. The mean values of nitrogen balance were -1.28% for low protein and 0.78% for high protein diet. All the subjects were in negative nitrogen balance at the low protein intake while they were in positive nitrogen balance at the high protein intake. The mean daily urinary nitrogen excretion increased with increased level of protein intake. Urea nitrogen was the largest part of the urinary nitrogen. The ratio of urea nitrogen to total urinary nitrogen increased significantly for 79 to 85% as protein intake was doubled.

• Journal of Nutrition and Health
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• 제21권2호
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• pp.99-112
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• 1988

This study was performed to investigate the effects of dietary protein and calcium levels on calcium metabolism in eight healthy Korean adult females. The 2-day metabolic study consisted of a 2 day adaptation period and three 6-day experimental periods. Three experimental diets were low protein low calcium(LPLCa : protein 44g, Ca 422mg), higher protein low calcium(HPLCa : protein 85g, Ca 365mg), and high protein high calcium (HPHCa : protein 84g, Ca 727mg). The apparent calcium absorption was likely to be affected by the calcium intake rather than by the protein intake. Average calcium absorption rate was about 23-29% of calcium intake. The calcium balance was -21.44mg for LPCa, -25.02mg for HPLCa, and -3.22mg for HPHCa. Avergae urinary calcium excretion was 127.7mg for LPLCa, 108.6mg for HPLCa, and 215.4mg for HPHCa. Urinary calcium excretion was more closely related to the changes of calcium intake rather than of protein intake. These results seemed to be due to the interactions between the high phosphours contained in the high protein diet and the little discrepancy of protein intake levels.