• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.113-121
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• 2024

Purpose: In response to the surge in coronavirus disease 2019 (COVID-19) omicron variant cases, we have implemented preemptive testing for preschool and school. The purpose is to quickly detect COVID-19 cases using a rapid antigen test (RAT) kit so that normal school activities can continue. Methods: The results entered in The Healthcare Self-Test App were merged with the information on the status of confirmed cases in the COVID-19 Information Management System by Korea Disease Control and Prevention Agency (KDCA) for preschool and school of students and staffs March 2 to May 1, 2022 to analyze the RAT positive rate and positive predictive value of RAT. Results: In preschool and school 19,458,575 people were tested, weekly RAT positive rate ranged from 1.10% to 5.90%, positive predictive value of RAT ranged from 86.42% to 93.18%. By status, RAT positive rate ranged from 1.13% to 6.16% for students, 0.99% to 3.93% for staffs, positive predictive value of RAT ranged from 87.19% to 94.03% for students, 77.55% to 83.10% for staffs. RAT positive rate by symptoms ranged from 76.32% to 88.02% for those with symptoms and 0.34% to 1.11% for those without symptoms. As a result of preschool and school RAT, 943,342 confirmed cases were preemptively detected, before infection spread in preschool and school. Conclusions: RAT was well utilized to detect confirmed cases at an early stage, reducing the risk of transmission to minimize the educational gap in preschool and school. To compensate for the limitations of RAT, further research should continue to reevaluate the performance of RAT as new strains of viruses continue to emerge. We will have to come up with various ways to utilize it, such as performing periodic and repeated RAT and parallel polymerase chain reaction.

• Korean Journal of Pharmacognosy
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• v.25 no.3
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• pp.238-248
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• 1994

The hypoglycemic and metabolic effects of Commelina communis L. extract were investigated in alloxan induced diabetic rats. The increased blood glucose level in the diabetic rats was significantly reduced and the loss of body weight was recovered with the treatment of the plant protein fractions($30{\sim}70%$ ammonium sulfate precipitates). Administration of the plant protein fractions elicited the significant increase of glucose-6-phosphate dehydrogenase (G-6-P DH) activity and liver weight which were decreased in the diabetic rat liver. G-6-P DH was partially purified from extract- or insulin-treated diabetics, diabetic control, and normal rat liver and studied for the biochemical properties. The $K_m$ value(9.002 mM) of diabetic rat liver enzyme was greatly higher than that (0.033 mM) of normal enzyme indicating the affinity of enzyme for the substrate was significantly reduced in the diabetic rat liver. This reduced affinity of enzyme for the substrate in the diabetic rat was recovered in the extract- or insulin-treated rat liver enzyme having 0.164 or 0.208 mM of their $K_m$ values, respectively. Although there was no significant difference in the optimum pH(6.0) and optimum temperature($37^{\circ}C$) of enzyme among the experimental groups, the dependence of their activities on pH appeared to be slightly resistant in the extract- or insulin-treated group compared to the diabetic group. In order to investigate the antigenicity of rat liver enzyme among experimental groups, enzyme-linked immunosorbent assay was carried out by using anti-G-6-P DH anti-serum. Absorbance(0.102) shown in the normal rat liver was reduced even below zero in the alloxan-diabetic rat liver, but increased again in the extract- or insulin-treated rat liver(0.096 or 0.118, respectively). The result of this study suggested that G-6-P DH may be used as a marker enzyme to diagnose and to indicate the progress of the diabetics, and the hypoglycemic effect of the extracts of Commelina communis L. was certainly associated with action or mode of G-6-P DH on the rat liver.

• Journal of the Korean Society of Radiology
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• v.15 no.3
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• pp.313-320
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• 2021

This study evaluates the radiation protection effects of Schizonepeta tenuifolia water extract on white rat by gender. Schizonepeta tenuifolia contains polyphenol and flavonoid, which are typical substances that remove free radical. Thus, to determine the effectiveness of radiation protection, the Schizonepeta tenuifolia water extract was administered to Sparaqu-Dawely (SD) rat males and females for two weeks, followed by hematological analysis, analysis of changes in the length of the small intestine villi length, and SOD activity evaluation. The male rat in ST+IR group showed a slightly greater recovery of platelets than the IR group. The ST+IR group also showed a higher platelet recovery capability than the IR group. lymphocyte showed that male and female rat ST+IR groups have higher resilience than IR groups likewise platelet. After irradiation, the villi length of the male rat and female rat decreased less in ST+IR group than in the IR group, indicating that the villi length of all genders was less damaged. This result confirmed that the Schizonepeta tenuifolia water extract had a radiation protection effect.

• Toxicological Research
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• v.6 no.1
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• pp.89-97
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• 1990

Neural regulation of phenylethanolamine N-meth-yltransferase (PNMT) was studied with reserpine as a neuronal agent in rat adrenal medulla. The enzyme activity assay and northern blot analysis were performed to determine whether the induction of PNMT activity after reserpine treatment was associated with elevation of mRNA coding for PNMT. The i.p. administration of reserpine (2.5 mg/kg) on alternate days fot 4 injections to rats brought about 30% increase of adrenal medullary PNMT activity and approximately 60% stimulation of the PNMT mRNA level in rat adrenal gland. A dose of 10 mg/kg of reserpine was chosen to perform optimum induction of PNMT activity in the rat adrenal gland based on the results of dose response curve of reserpine. Time course reserpine (10 mg/kg) effects on the rat adrenal medullary PNMT were as follows: 1. Peripheral PNMT activity reached maximum level after 7 days of drug treatment on alternate days. 2. Trans-synaptic stimulation by reserpine increased pretranslational activity of rat adrenal PNMT, but not translational activity. 3. Immunotitration of PNMT molecule after reserpine treatment indicated that reserpine produced an enzyme with greater antibody affinity than endogenous molecule in the rat adrenal gland.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.251-255
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• 1998

Rat testis known to contain all of the enzymes required for carnitine biosynthesis also contains high concentration of calmodulin, a protein which may or may not contain trimethyllysine, the major substrate in carnitine biosynthesis. The purpose of this study was to investigate the levels of carnitine and the state of calmodulin N-methylation in rat testes, and to discuss the possibility of the involvement of calmodulin incarnitine biosynthesis. Nonesterified carnitine , acid soluble acyl carnitine, and acid insoluble acyl carnitine of ra tests were 273 nmole, 62nmole, and 4 nmole/g tissue, respectively. Total carnitine level was 339 nmole/g testes tissue. Calmodulin purified from rat tests was assayed for methylation potential using N-methyltransferase from the rat testes. Rat testes calmodulin showed no 3H-methyl incorporation indicating that the calmodulin was trimethylated already by endogenous calmodulin N-methyltransferase. Amino acid composition analysis revealed that the rat testes calmodulin containd one mole of trimethyllysine per mole of calmodulin. These data suggest that testes calmodulin could provide the trimethyllysine needed for the synthesis of carnitine in the rat tests.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.1
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• pp.13-20
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• 1991

For this experiment frist the fermented Soybean Meju was prepared by domestic ordinary method of Korean and concentrated Meju suspensoidal extract was made for toxicological test sample on mice and rat. Even the oral dose of 10g extract per kg of mice had not any acute toxicity. So the median lethal dose(LOD50) is lilely to be much greatr or not to be. In comparison of the average weight gain rate for 4 weeks the control and test groups of 0.308g Ex/rat kg and 9.24g Ex/rat kg daily were the much the same as about 19% but 3.08g Ex/rat kg group waas exceptionally 2.7% higher than control For this period all test groups did not show any abnormality in appearance and anatomic findings. In serum GPT GOT alkaline phosphatase and blood urea nitrogen value there were no difference significantly between control and the test groups of 0.308g/rat kg and 3.08g/rat kg but 9.24g/rat kg group was some what higher than control. Especially in cholesterol alkaline phosphatase and blood urea nitrogen value 9.24g/rat kg group or 28days had 100mg/이 37.5u 32mg/이 respectively which were increased significantly. The pathological findings of all test groups especially 9.24g/kg group did not showed any characterized sign of acute or subacute liver damage or intestine lesion. So it is supposed that there is not any tocixants originated from some molds in fermented Korean domestic Meju which is prepared traditionally in winter.

• Clinical and Experimental Reproductive Medicine
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• v.18 no.1
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• pp.41-48
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• 1991

The present investigation has been undertaken to elucidate the functional role of ovarian steroids on the mechanism of oviduct differentiation during early embryonic development in rat. The activity of alkaline phosphatase (ALPase) was measured in the oviduct tissue under different steroids treatment regime on day 9 pregnancy. The ALPase activity of the oviduct of pseudopregnant rat was compared with that of normal pregnant rat. The results of day 9 pregnancy rat oviduct clearly demonstrated that $17{\beta}-estradiol$ and progesterone were effective in pseudopregnant rat oviduct. In the ovary intact group the ALPase activity was similar in both of normal and pseudopregnant oviduct, but in the $17{\beta}-estradiol$ treated group the ALPase activity in normal pregnancy was significantly higher than that in pseudopregnancy. The effect of estradiol on the normal pregnant rat oviduct was apparently found on day 3 and day 9 pregnancy. This study, therefore, clearly demonstrates that $17{\beta}-estradiol$ is much potent in oviduct tissue differentiation. It is suggested that absence of $17{\beta}-estradiol$ effect on pseudopregnant rat oviduct is due to there is no embryo passing througth the oviduct.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.2
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• pp.157-161
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• 1999

Recent studies clearly demonstrated that the novel expression of LH gene in the rat testis, and suggested the local action of the LH-like molecule. The present study was performed to analyze the expression of LH genes in the rat accessory reproductive organs. Expression of LH subunit genes in the rat uterus and epididymis was demonstrated by reverse transcription-polymerase chain reaction (RT-PCR) and specific LH radioimmunoassay (RIA). The $LH_{beta}$ transcripts in these organs contained the published cDNA structure, the pituitary type exons 1-3, which encoded the entire $LH_{beta}$ polypeptide. Presence of the transcripts for the ${\alpha}$-subunit in the rat reproductive tissues were also confirmed by RT-PCR. In the LH RIA, significant levels of LH were detected in crude extracts from the rat ovary, uterus and epididymis. The competition curves with increasing amount of tissue extracts were parallel with those of standard peptide, indicating that the immunoreactive LH-like materials in these tissues are similar to authentic pituitary LH molecule. In rat epididymis, the highest amount of immunoreactive LH was detected in corpus area. Our findings demonstrated that the genes for LH subunits are expressed in the rat accessory reproductive organs, and suggested that these extrapituitary LH may act as a local regulator with auto and/or paracrine manner.

• BMB Reports
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• v.34 no.5
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• pp.408-414
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• 2001

Ornithine decarboxylase (EC 4.1.1.17) is an essential enzyme for polyamine synthesis and growth in mammalian cells and plants. We compared the biochemical and immunological properties of rat and Nicotiana glutinosa ODC by cloning and expressing the recombinant proteins. The primary amino acid sequence between rat and N. glutinosa ODC had a 40% homology The molecular weight of the overexpressed rat ODC was 53 kDa, and that of N. glutinosa was 46.5 kDa. Adding 1 mM of putrescine to the enzyme reaction mixture inhibited both rat and N. glutinosa ODC activity to 30%. Agmatine had an inhibitory effect only on N. glutinosa ODC. Cysteine and lysine modifying reagents reduced both ODC activities, verifying the key roles of cysteine and lysine residues in the catalytic mechanism of ODC. ELISA was performed to characterize the immunological difference between the rat and plant ODC. Both the rat and N. glutinosa ODC were recognized by the polyclonal antibody that was raised against purified N. glutinosa ODC, but the rat ODC was 50-fold less sensitive to the antibody binding. These results indicate that even though both ODCs have the same evolutionary origin, there seems to be a structural distinction between the species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.1
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• pp.27-33
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• 1996

납중독에 대한 마늘의 antidotic effect를 조사하기 위한 4주간의 실험에서 , rat 체중 kg 당 중 (7일간) 1회초산납 100mg을 투여한 rat에 매일 마늘즙을 식이의 4%로 투여한 실험군(LG)과 초산납과 함께 중금속 해독제인 N-acetyl penicillamine을 매일 rat 체중 kg당 100mg 투여한 실험군 (LP)의 체중 증가율 비교에서 초산납만을 투여한 실험군(L)보다 LG군과 LP군 모두 유의성 있는 rat 성장률 개선효과 (각각 +13.3%과 +22.3%)를 보였다. L군 rat의 외관과 해부검사에서는 장기들(위, 간장, 신장)의 병변(damage)이 매우 미미하게 관찰되었으나 혈액검사에서 GOT, alkaline phos-phatase, blood uric acid, blood urea nitrogen, crea-tinine, bilitrubin 값이 유의적을 증가하여 납중독에 의한 장기(organs) 특히 신장 기능의 현저한 장해를 보였다. 그러나 LG군이 이들 측정값이 L군보다 유의성의 차로 낮은 값을 보여 LP군과 거의 비슷한 수준이었다. 특히 L군에서는 Pb 중독으로 인하여 hemo-globin 량이 정상 이하(10.37g/dl)로 감소되었으나 LG군에서는 L군에서와 같이 거의 정산 (12.32g/dl)을 유지하였다. L군의 혈액, 간장 및 신장의 납 합량은 각각 0.281, 0.250, 0.403ppm으로 대조군 보다 매우 높았으나 LG군은 대조군에 가깝게 그리고 LP군과는 거의 같은 수준(각각 0.182, 0.131, 0.253ppm)으로 낮아졌다. 이상의 실험 결과에서 마늘이 rat의 납중독에 미치는 효과를 N-acetyl penicillamine의 해독 효과와 비교할 때 마늘의 해독 효과라고 볼 수 있는 유의성있는 측정값들이 관찰되었다.