• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.91-99
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• 1992

Cell structure is based on proteins. Since the antibody is proteous substance, the continous low protein feeding decreases the resistance of host against pathogenic agents. The present study was designed to investigate the infectivity of protozoa to rats which were fed with variously prescribed diets. Experimental group was divided into 4 groups according to the level of casein in the diet, group I: casein 0%, group II: casein 5%, group III: casein 15%, group IV: casein 30%. Each animal was fed for 5 weeks followed by inoculation of protozoa in cecum and sacrified each 1 week later of the infection. Each diet group, non infected with protozoa was recognized as the control. Result are summerized as follows : 1. All the rats of group I died in 2∼4 weeks and 2 of 12 rats in group II were also died in the period. 2. The growth rate and FER were high in group III and IV compared with group II. Therefore low protein feeding decrease growth and feed efficaly ratio(FER). 3. The pH of caecal contents between the infected group and control showed no difference, but the values of group III and IV were higher than the group II. Low pH of the caecal contents provides a suitable condition for determining their susceptibility to Entameoeba histolytical trophozoite. 4. Amounts of serum total protein in group II, III and IV showed no significant difference with the control and infected group, but amounts in group III and IV were higher than the group II. Therefore, continuous low protein feeding decrease serum total protein. 5. Albumin, ${\alpha}$1, gloulin, ${\alpha}$2 globulin, ${\beta}$ globulin, ${\gamma}$ gloulin of group III and IV were all high to compare than the group II. Albumins of group III and IV of control was higher than infected group, but there was no difference in ${\gamma}$ globulin between the infected and control group.

• Journal of Life Science
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• v.5 no.2
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• pp.57-62
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• 1995

Casein or soybean protein was subjected to there action with caffeic acidtyrosinase system at 30-35$\circ$C, pH 6.8 with aeration for 5hr. The resulting brown proteins were washed with acetone until the washings were on longer colored. However, modified protein still retained a light brown. The effects of the modified proteins and brown compounds on male Wistar strain rats were studied by pair-feeding of a cholesterol-free diet for 14days. Significant decrease in protein digestibility for the rats fed with the modified proteins were observed. Weight gain and protein digestibility were not influenced by feeding brown compounds, but the feeding of brown compound from casein caused an enlargement of caecum. The concentrations of serum cholesterol and triglyceride in the rats fed with modified proteins and brown compounds were mostly unchanged against the rats fed with untreated proteins. These results suggest that the decrease in protein digestibility induced by enzymic browning-reaction did not cause the decrease in concentration of serum cholesterol.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.743-749
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• 2004

The gene encoding human serum albumin (HSA) was cloned from human liver cDNA library by PCR. The HSA cDNA in size of 2,176 bp, including 1,830 bp of open reading frame, was cloned into the plasmid carried with the 5'flanking sequence of goat $\beta$-casein gene (-4,044 to +2,025 bp) to get a tissue specific expression vector in mammary gland named pGB562/HSA (12.5 kb). A 9.6 kb DNA fragment in which the sequence is in order of goat $\beta$-casein gene regulatory sequence, HSA cDNA and SV40 polyadenylation signals was isolated from the pGB562/HSA by SacI and DraIII cutting, and used to microinject into the pronuclei of mouse fertilized eggs to produce transgenic mice. Three transgenic mice (2 female and 1 male) were identified by PCR and dot Southern blot analysis. The copy numbers of integrated transgene were more than 10 copies in line #21 and #26 as well as over 50 copies in line #31 of transgenic mice. HSA protein collected from the milk of lactating transgenic mice was confirmed by immuno-detection of Western and slot blot. The concentrations of HSA in the milk were from 0.05 to 0.4 mg/ml. An obvious antigen and antibody conjugate could be observed in immunohistochemical stain of mammary gland tissue from lactating day 11 of HSA transgenic mice. The transmission of transgene and its expression was recognized according to the results of RT-PCR and sequences analyses of their progeny.

• Journal of Nutrition and Health
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• v.21 no.4
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• pp.197-212
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• 1988

To study the effect of preventing the browning reaction between casein and glucose by protecting the reactants using corn starch with coating material, rats were fed for 30 days nonbrowning diet, nonprotected browning diet, browning diet protected only casein, browning diet protected both casein and glucose and browning diet supplement sucrose simultaneously with protecting both casein and glucose. The amounts of fructosyl-lysine excreted through urine were greater than those through feces regardless of diets and the both side of the excreted amounts of fructosly-lysine through urine or feces were greater for rats fed browning diets regardless protecting compared to rats fed the nonbrowning diet. Through urine, the excreted amounts of fructosyl-lysine were decreased for rats fed the browning diet supplemented sucrose simultaneously with protecting both casein and glucose than those for rats fed the nonprotected browning diet and through feces, were decreased for rats fed protected browning diets regardless of protecting method than the nonprotected browning diet. The excreted amounts of all individual essential free amino acids through feces were increased for rats fed browning diets irrespective of protecting compared to the nonbrowning diet, but through urine, were increased or similar level for rate fed the nonbrowning diet compared to browning diets except histidine. The excreted amount of free lysine through feces were decreased for rats fed protected browning diets than nonprotected browning diet. Fructosyl-lysine contents of serum, liver and small intestinal digesta were increased for rats fed browning diets regardless of protecting by starch compared to nonbrowning diet but, of serum and small intestinal digesta were decreased for rats fed protected browning diets than the nonprotected browning diet.

• Journal of Dairy Science and Biotechnology
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• v.29 no.1
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• pp.59-63
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• 2011

This study was carried out to investigate the change of components which raw milk has during cold storage. General component content of raw milk (fat, protein, lactose, total solids) was decreased in proportion to the length of cold storage. The pH of raw milk was decreased in according to the length of cold storage. In electrophoresis images, ${\beta}$-casein which was one of the composition of raw milk was decreased as the period of cold storage extended on the other hand, the content of Ca and P in the serum casein was increased in accordance with the length of cold storage.

• Journal of Nutrition and Health
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• v.40 no.4
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• pp.320-326
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• 2007

An important related question is whether arginine has influence bone metabolism. The effect of arginine supplements on bone markers and related hormones were studied in young female Sprague-Dawley rats fed either an arginine supplemented diet or control diet. Twenty four rats (body weight 83${\pm}$5 g) were randomly assigned to one of two groups, consuming casein or casein with supplemented arginine diet. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. Bone formation was measured by serum osteocalcin and alkaline phosphatase (ALP) concentrations. And bone resorption rate was measured by deoxypyridinoline (DPD) crosslinks immunoassay and corrected for creatinine. Serum osteocalcin, growth hormone, estrogen, insulin-like growth factor-1 (IGF-1), parathyroid hormone (PTH) and calcitonin were analyzed using radioimmunoassay kits. The weight gain and mean food intake were not affected regardless of diets. The rats fed arginine-supplemented diet had not significantly different in ALP, osteocalcin, crosslinks value, PTH, estradiol, and IGF-1 compared to those fed casein diet group. The arginine-supplemented group had significantly higher growth hormone and calcitonin than casein group. This study suggests that arginine is beneficial for bone formation in growing female rats. Therefore exposure to diet which rich in arginine early in life may have benefits for bone formation and osteoporosis prevention.

• Preventive Nutrition and Food Science
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• v.7 no.3
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• pp.278-281
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• 2002

The objective of the current study was to determine the influences of dietary proteins and methionine on plasma lipid concentrations. Thirty growing male Sprague-Dawley rats were fed diets similar in all respects except that dietary protein was from either casein, soy protein isolate, or soy protein isolate supplemented with L-methionine (0.24 %). The animals were fed experimental diets ad libitum for nine weeks. Plasma total-cholesterol concentrations were unaffected by the protein source or methionine supplementation. Plasma triglyceride concentrations were lower in rats of methionine supplemented soy protein diets (76 mg/dL) than in the rats fed casein or soy diet (120 mg/dL, 109 mg/dL, respectively). These results indicate that soy protein reduces plasma triglycerides relative to casein in rats fed cholesterol free diets, and that methionine-supplemented soy diets decrease plasma triglyceride concentrations more than soy protein alone.

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.318-327
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• 1985

This study was designed to investigate the effect of early protein undernutrition of rats on later susceptibility to lead poisoning. Weanling rats, weighing about 55 grams, were malnourished by feeding low protein diets ( 12% and 5% casein diet ) during the four weeks of protein deprivation period. For the following 5 weeks, the malnourished rats were fed with 25% casein diet as rehabilitation diet. After the rehabilitation period, all rats were fed with 25% casein diet and the drinking water containing 2000ppm-Pb during the four weeks. The results obtained were as follows ; 1 ) Feed intake, body weight gain and food efficiency ratio were reduced in all rats exposed to lead, especially in rats fed with 5% casein diet during the four weeks of weanling period. 2 ) Enlargement of kidney and spleen were observed in all rats exposed to lead and were more remarkable in rats fed with 5% casein diet. 3 ) In rats exposed to lead, activity of serum glutamic oxaloacetic transaminase ( S- GOT ) was significantly increased by increasing the degree of early protein deprivation, whereas hematocrit value was significantly decreased. Activity of serum glutamic pyruvic transaminase ( S- GPT ) was shown a tendency to increase by increasing the degree of early protein deprivation, but the difference was not significant. 4) In rats exposed to lead, the amount of lead accumulation in kidney was increased by increasing the degree of early protein deprivation. The significant increase was shown in rats fed with 5% casein diet during the four weeks of weanling period. The results of the experiment suggest that early protein undernutrition, even after some period of rehabilitation, may enhance the later susceptibility to lead poisoning.

• Journal of Nutrition and Health
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• v.27 no.1
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• pp.3-11
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• 1994

This study was carried out to examine how dietary protein and calcium levels in rats fed fat-enriched diet affect the total lipid and cholesterol contents of blood and tissues. Male Sprauge-Dawley rats weighing approximately 200g were fed six purified diets which contained 18%(w/w) beef tallow, 1% (w/w) cholesterol, two source of protein, casein or isolated soy protein (ISP) and three levels of dietary calcium, 0.1%, 0.4% and 1.0%, first, for four weeks, and second, for eight weeks. The contents of the total lipid, cholesterol and triglyceride in blood, liver, heart and feces were determined. After four weeks feeding serum lipid and cholesterol concentrations significantly decreased in rats fed 1.0% (w/w) level calcium, regardless of dietrary protein sources. After eight weeks, these concentrations were significantly lower in the rats fed soy protein than in casein-fed rats. As dietary calcium level increased serum and tissue lipid and cholesterol contents were decreased and fecal lipid excretion increased. It is concluded that hypolipidemic and/or hypocholesterolemic effects of soy protein and calcium were partly due to decrease in lipid absorption.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.246-253
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• 1997

This study was conducted to investigate the effect of protein kinds and levels on lipid metabolism in hypercholesterolemia rats. Male Sprague Dawley rats were administrated 1% cholesterol and 0.25% sodium cholate to induce hypercholesterolemia and were fed on diet containing two levels(7, 20%) of casein and soy protein respectively. The rats were sacrified after 5 weeks of feeding periods. Total lipid content in serum was decreased in proportion to level of protein and soy protein was more effective than casein in lipid-lowering effect. Serum triglyceride content was significantly decreased in proportion to level of protein and did not show significance by protein kind. Serum phospholipid content was more significantly decreased in 20% protein groups than that of 7% protein groups. Total cholesterol content in serum was significantly decreased by protein and were decreased in proportion to level of soy protein. Free cholesterol content did not show significance by protein level. The degree of decrease predominated in soy protein groups. Serum HDL-cholesterol content and RL-cholesterol were increased in proportion to level of protein and effect of soy protein was not more significantly than that of casein. Atherogenic index was significantly decreased in proportion to level of protein and soy protein groups were more effective. Serum LDL-, VLDL-cholesterol contents were more significantly decreased in 20% protein groups than that of 7% protein groups. Serum $\beta$-lipoprotein and chylomicrone-cholesterol contents also showed significantly decrease by soy protein.