• 대한의생명과학회지
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• 제8권4호
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• pp.235-244
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• 2002

This study was carried out to determine the blood and milk progesterone by enzyme-linked immunosorbent assay (ELISA), and milk urea nitrogen (MUN) in cows. MUN and protein concentration were determined using automated infared procedures. The optimum conditions of ELISA system was investigated including the first and second antibody titres, bound percent, and enzyme conjugate and also the factors on MUN and protein concentration by sampling procedures and addition of preservatives. Progesterone antibodies did not react to pregnenlone, testosterone, estrone, estradiol-l7$\beta$, aldosterone, cortisol, corticosterone and 11$\alpha$-dehydroxycortisone (DOC), but reacted with only progesterone. The intra and inter-assay coefficient of variation 4.5%, 6.1~9.4% when used of bovine serum. The morning, MUN concentration (17.6$\pm$2.8 mg/100 ml) in the 13 herds was similar to that of evening MUN concentration of the lactating cows from the same herd. A significant relationship between morning and evening milk samples of upper parameters was found r=0.93. Difference in MUN concentration with sampling procedures and using of preservatives were investigated.

• Journal of Applied Biological Chemistry
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• 제51권3호
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• pp.102-110
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• 2008

Complementation assay of the urea uptake-defective yeast mutants led to the identification of the Arabidopsis AtTIP4;1 gene encoding the aquaporin. However, its physiological functions still remain elusive. In the present study, histochemical and genetic analyses were performed to understand the physiological roles of AtTIP4;1 in urea uptake. The AtTIP4;1 product was detectible in the roots, but not in the leaves, the stem, and the flower. Its promoter allowed the expression of the $\beta$-glucuronidase reporter gene in the roots and the apical meristem in Arabidopsis. The AtTIP4;1 products were induced under nitrogen-deficient conditions. To investigate the role of the tonoplast intrinsic protein in urea transport and developments, Arabidopsis with the loss- and the gain-of-function mutations by T-DNA insertion in AtTIP4;1 and 35S promoter-mediated overexpression of AtTIP4;1 were identified, respectively. The transfer DNA insertion and the AtTIP4;1-overexpressed plants showed normal growth and development under normal or abiotic stress growth conditions. The urea-uptake studies using $^{14}C$-labeled urea revealed higher accumulation of urea in the AtTIP4;1-overexpressed plants. These results provide evidence that overexpression of AtTIP4;1 leads to the increase in the urea-uptake rate in plants without detectable defects to the growth and development.

• Biomolecules & Therapeutics
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• 제26권6호
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• pp.608-615
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• 2018

Benzalkonium chloride, diazolidinyl urea, and imidazolidinyl urea are commonly used preservatives in cosmetics. Recent reports suggested that these compounds may have cellular and systemic toxicity in high concentration. In addition, diazolidinyl urea and imidazolidinyl urea are known formaldehyde (FA) releasers, raising concerns for these cosmetic preservatives. In this study, we investigated the effects of benzalkonium chloride, diazolidinyl urea, and imidazolidinyl urea on ROS-dependent apoptosis of rat neural progenitor cells (NPCs) in vitro. Cells were isolated and cultured from embryonic day 14 rat cortices. Cultured cells were treated with 1-1,000 nM benzalkonium chloride, and $1-50{\mu}M$ diazolidinyl urea or imidazolidinyl urea at various time points to measure the reactive oxygen species (ROS). PI staining, MTT assay, and live-cell imaging were used for cell viability measurements. Western blot was carried out for cleaved caspase-3 and cleaved caspase-8 as apoptotic protein markers. In rat NPCs, ROS production and cleaved caspase-8 expression were increased while the cell viability was decreased in high concentrations of these substances. These results suggest that several cosmetic preservatives at high concentrations can induce neural toxicity in rat brains through ROS induction and apoptosis.

• Applied Biological Chemistry
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• 제24권1호
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• pp.15-20
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• 1981

본 실험에서는 요소(尿素) 엽면시비(葉面施肥)에 의한 잎내 urease 효소의 활성도(活性度)에 미치는 영향을 콩, 라이맥, 토마토, 무 및 배추를 공시재료(供試材料)로 사용하여 조사하였다. urease 활성도(活性度)의 정확한 측정을 위하여 효소조액(酵素粗液)에 포함되어 있는 암모니아 이용 효소 중에서 열(熱)에 약한 효소의 불활성화(不活性化)를 꾀하고져 효소 반응액을 $60^{\circ}C$에서 3시간 동안 처리시켰다. 뇨소 처리를 받은 잎에서 urease 비활성도(比活性度)가 뇨소 무처리구(無處理區)에서 보다 엽면살포 후 일반적으로 2 내지 4일 동안에는 약간 높은 경향(傾向)을 보였다. 뇨소 처리구와 무처리구 간의 효소비활성도 차이는 어느 식물에서나 뇨소 처리 후 48시간 경과하였을 때 가장 두드러지게 나타났다. 콩과 라이맥의 경우에는 각가 6%와 10% 정도 높았고 토마토와 무에서는 약 20%정도, 배추에서는 60%정도의 차이가 있었다. 단백질의 함량은 콩과 토마토의 경우에서는 뇨소 처리구에서 엽면살포 후 약5일 동안 대조구(對照區)에 비해 높은 수준(水準)을 유지했으나 라이맥, 우무 및 배추에서는 본 실험기간 동안에는 큰 차이를 보이지 않았다. 잎내의 암모니아 농도는 urease 활성이 증가된 뇨소 처리구에서 오히려 약간 낮은 값을 보였다. 이상(以上)의 실험결과들은 뇨소의 엽면살포시 식물의 잎속으로 흡수(吸收)되어 들어간 뇨소가 urease의 생합성을 유도(誘導)하여 빨리 질소원(窒素源)인 뇨소를 식물 성장에 필요한 다른 대사물로 전환시켜 결과적으로 단기간내에 식물의 생육상태(生育狀態) 개선(改善)을 촉진시킨다고 사료된다.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.183-194
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• 2008

A variety of stem cells has been emerging as therapeutic cells that can replace organ transplantation in human liver diseases. The present study focused on whether human eyelid adipose-derived stem cells (HAD) might differentiate into functional hepatocyte-like cells in vitro. HAD were isolated from human eyelid adipose tissue. Effect of dimethyl sulfoxide (DMSO), fibroblast growth factor (FGF)-2 and FGF-4 on the hepatic differentiation of HAD have been examined in vitro. Immunocytochemical analysis and PAS staining showed that HAD cultured in both DMSO and FGF-4 exhibited the most intense staining than HAD of the other experimental groups. These HAD expressed numerous hepatocyte-related genes. Immunoblotting analyses showed that HAD cultured in the presence of DMSO and FGF-4 secreted higher amount of human albumin than HAD cultured in other conditions. Urea analysis also demonstrated that these HAD produced higher amount of urea than any other groups of HAD. In conclusion, combined treatment of DMSO and FGF-4 could effectively induce the functional differentiation of HAD into hepatocyte-like cells.

• 한국식품과학회지
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• 제32권6호
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• pp.1221-1226
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• 2000

대두단백질의 분석을 위한 효소면역측정법을 개발하고자 특이항체를 생산하고 그 항체의 특성을 비교하였다. 분리대두단백(ISP), ISP를 SDS와 urea의 첨가하에 열처리한 것(ISP(SU)), 11S 글로불린의 acidic subunit(AS)를 각기 면역하여 다클론 항체를 생산하였다. 간접 경합 효소면역측정법(ciELISA)을 실시하여 처리를 달리한 대두단백질에 대한 이들 항체의 반응성을 조사하였여 $IC_{50}$으로 나타내었다. 항AS 항체의 경우 $IC_{50}$값이 ISP, ISP(SU), ISP를 2-ME로 처리한 ISP(ME), crude 11S에 대하여 각각 20, 2, 2.5, $200\;{\mu}g/mL$로 나타났다. 또한, 항ISP(SU) 항체의 경우 같은 항원에 대해서 100, 5, 4, $220\;{\mu}g/mL$였으며 항ISP 항체의 경우는 각각 20, 30, 36, $1000\;{\mu}g/mL$로 나타났다. 이로서 생산된 3가지 항체 중에서 항AS 항체가 대두단백질에 대한 반응성이 가장 우수하여 ELISA분석법 개발에 적합하였다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제19권2호
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• pp.96-103
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• 2016

Helicobacter pylori infection is acquired mainly during childhood and causes various diseases such as gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue (MALT) lymphoma, and iron deficiency anemia. Although H. pylori infection in children differs from adults in many ways, this is often overlooked in clinical practice. Unlike adults, nodular gastritis may be a pathognomonic endoscopic finding of childhood H. pylori infection. Histopathological findings of gastric tissues are also different in children due to predominance of lymphocytes and plasma cells and the formation of gastric MALT. Although endoscopy is recommended for the initial diagnosis of H. pylori infection, several non-invasive diagnostic tests such as the urea breath test (UBT) and the H. pylori stool antigen test (HpSA) are available and well validated even in children. According to recent data, both the $^{13}C$-UBT and HpSA using enzyme-linked immunosorbent assay are reliable non-invasive tests to determine H. pylori status after eradication therapy, although children younger than 6 years are known to have high false positives. When invasive or noninvasive tests are applied to children to detect H. pylori infection, it should be noted that there are differences between children and adults in diagnosing H. pylori infection.

• 대한의생명과학회지
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• 제9권1호
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• pp.29-36
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• 2003

Progesterone levels in the blood plasma or skim milk of cows are considered to be very useful indicator fur the detection of estrus cycle and early pregnancy diagnosis. During 13 to 14 days after estrus the level of progesterone in plasma or skim milk were not different between the inseminated arid non-inseminated cows. In the pregnant cows the peak level of progesterone reached on 14th day after artificial insemination (AI), but in the absence of conceptus the level declines after the 14th day slowly, and then very rapidly towards the basal level after the 17th day. This low level persists about 4 days, including those of estrus and ovulation a highly characteristic pattern which differs so markedly from that in the pregnant cows. Progesterone levels in blood plasma or skim milk can provided a reliable diagnosis of early pregnancy and monitoring ovarian activity in cows. The mean $\pm$ standard deviation of milk urea nitrogen(MUN) and protein concentration in the cows at 9 herds were 17.7$\pm$2.35 mg/dL and 3.2$\pm$0.17%, respectively. The days of nonpregnant after parturition was shorter in the cows in which the lower level of MUN than higher level of MUN concentration.

• Journal of Microbiology
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• 제39권4호
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• pp.279-285
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• 2001

Vibrio parahaemolyticus is a halophilic bacterium associated with seafood gastroenteritis. An unusual strain of Kanagawa-positive urease producing Vibrio parahaemolyticus O1:K1 was isolated from the environment and identified . A polymerase chain reaction assay revealed that this strain harbored both the tdh and the genes. The urease from this strain was studied. Maximum urease production was induced in LB medium containing 0.2% urea, 0.5% glucose, 2% NaCl and pH 5.5 with 6h of culti-vation at 37$\^{C}$ under aeration. Purification of urease was achieved by the process of whole cell lysate, 65% ammonium sulphate precipitation, DEAE-cellulose ion exchange column chromatography, Sepharose CL-6B gel filtration and oxirane activated Sepharose 6B-urea affinity chromatography with 203 fold purification and 2.2% yield. Analysis of the purified enzyme by SDS-PAGE demonstrated the presence of the subunits with a molecular weight of 85kDa, 59kDa, 41kDa and the molecular weight for the native enzyme by nondenaturing PAGE and gel filtration chromatography was 255kDa. The purified urease was stable at pH 7.5 and the opeimal pH in HEPES buffer was 8.0 The enzyme was stable at 60$\^{C}$ for 2 h with a residual activity of 32% . The addition of 10$\mu$M if NiCl$_2$maintained stability for 30 min. The Km value of the purified enzyme was 35.6 mM in urea substrate. The TD$\_$50/(median toxic dose) of the purified urease was 2.5$\mu\textrm{g}$/ml on human leukemia cells.

• BMB Reports
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• 제35권2호
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• pp.143-154
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• 2002

The structural and functional aspects of ervatamin B were studied in solution. Ervatamin B belongs to the $\alpha+\beta$ class of proteins. The intrinsic fluorescence emission maximum of the enzyme was at 350 nm under neutral conditions, and at 355 nm under denaturing conditions. Between pH 1.0-2.5 the enzyme exists in a partially unfolded state with minimum or no tertiary structure, and no proteolytic activity. At still lower pH, the enzyme regains substantial secondary structure, which is predominantly $\beta$-sheet conformation and shows a strong binding to 8-anilino-1-napthalene-sulfonic acid (ANS). In the presence of salt, the enzyme attains a similar state directly from the native state. Under neutral conditions, the enzyme was stable in urea, while the guanidine hydrochloride (GuHCl) induced equilibrium unfolding was cooperative. The GuHCl induced unfolding transition curves at pH 3.0 and 4.0 were non-coincidental, indicating the presence of intermediates in the unfolding pathway. This was substantiated by strong ANS binding that was observed at low concentrations of GuHCl at both pH 3.0 and 4.0. The urea induced transition curves at pH 3.0 were, however, coincidental, but non-cooperative. This indicates that the different structural units of the enzyme unfold in steps through intermediates. This observation is further supported by two emission maxima in ANS binding assay during urea denaturation. Hence, denaturant induced equilibrium unfolding pathway of ervatamin B, which differs from the acid induced unfolding pathway, is not a simple two-state transition but involves intermediates which probably accumulate at different stages of protein folding and hence adds a new dimension to the unfolding pathway of plant proteases of the papain superfamily.