• 농업과학연구
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• 제21권2호
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• pp.142-147
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• 1994

Carboxyrrethyl cellulose CM32 (Whatman Biochemical Ltd.)로 조제한 TNP-cellulose에 대하여 섬유소 분해효소의 활성도 측정을 위한 기질로서의 특성을 검토하였다. 섬유소 분해효소에 의한 TNP-cellulose의 가수분해는 Michaelis-Menten kinetics에 의하였으며, 그 분해의 위치가 amide결합이 아니고 섬유소 부분임을 확인하였다. 효소원이 다른 세가지 섬유소 분해효소 (Onozuka R-10 from Trichoderma viride; Cellulase II from Aspergillus niger; cell-free enzyme from Cellulomonas sp.)의 활성도를 TNP-cellulose를 기질로 하여 측정할때 그 반응조건을 기왕의 환원당 측정법과 비교해 보면: 반응 온도의 범위에는 변화가 없었으나, pH범위는 여러 효소에서 다소 넓어짐으로서 TNP-cellulose를 기질로 할때 수소이온의 영향을 적게 받음을 확인하였다. TNP-cellulose를 기질로 사용한 활성도 측정방법은: 세가지 효소 모두 일정 농도의 범위에서 활성도와 비례관계가 성립함으로서 효소원이 다른 여러 섬유소 분해효소에 적용할 수 있으며; 기왕의 DNSA법에 의한 환원당 측정법보다 감도가 높았고; 그 활성도의 값은 기왕의 환원당 측정법이나 점성도 측정법에 의한 결과와 대체로 비례적이었으나, 효소의 종류에 따라서 점성도 측정법의 결과와 반드시 일치하지는 않음으로서, 순수한 endo-효소의 활성도 측정을 위한 특이적인 방법이 되지 못함을 알수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제31권8호
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• pp.1119-1126
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• 2018

Objective: Present investigation was aimed to study the Single Nucleotide Variants of the luteinizing hormone beta ($LH{\beta}$) gene and to analyze their association with the semen quality (fresh and post-thawed frozen semen) and luteinizing hormone (LH) concentrations in Murrah buffalo bulls. Methods: Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) and Sanger sequencing method is used to study genetic variability in $LH{\beta}$ gene. LH assay was carried out using enzyme-linked immunosorbent assay method. A fixed general linear model was used to analyze association of single nucleotide polymorphism (SNP) of $LH{\beta}$ gene with semen quality in 109 and LH concentrations in 80 Murrah bulls. Results: $LH{\beta}$ gene was found to be polymorphic. Total six SNPs were identified in $LH{\beta}$ gene g C356090A, g C356113T, g A356701G, g G355869A, g G356330C, and g G356606T. Single Stranded Conformational Polymorphism variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on sperm concentration (million/mL), percent mass motility, acrosome integrity and membrane integrity in fresh and frozen semen whereas significant (p<0.05) effect was observed on percent live spermatozoa. SSCP variants of pattern 2 of exon 1+pattern 2 of exon 2+pattern 1 of exon 3 had highly significant (p<0.01) effect on luteinizing hormone concentrations too. Conclusion: The observed association between SSCP variants of $LH{\beta}$ gene with semen quality parameters and LH concentrations indicated the possibilities of using $LH{\beta}$ as a candidate gene for identification of markers for semen quality traits and LH concentrations in Murrah buffaloes.

• 대한영상의학회지
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• 제82권6호
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• pp.1524-1533
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• 2021

목적 인터페론-감마 분비 검사(interferon-gamma release assay; 이하 IGRA) 결과가 양성인 의료종사자의 흉부 X선(chest X-ray; 이하 CXR) 및 CT 결과를 기반으로 결핵의 발생률을 조사하고, 결핵 진단에서 진단 영상의 추가적인 역할을 알아보고자 하였다. 대상과 방법 IGRA를 시행 받은 1976명의 의료 종사자 중에서 IGRA 양성자를 후향적으로 조사하였다. 상부 폐야의 군집 결절 또는 선형 음영을 흉부 X선 양성으로 간주하였고, CT 결핵소견은 활성, 활동성미정, 비활동성, 정상으로 분류하였다. 활성 또는 활동성미정을 CT 양성으로 정의하였다. 결과 IGRA 검사 결과 255명(12.9%)에서 양성이었다. CXR과 CT는 각각 249명(99.2%)과 113명(45.0%)에서 시행되었다. CXR 양성 소견은 249명 중 7명(2.8%), CT 양성 소견은 113명 중 9명(8.0%)에서 각각 나왔다. 9명의 CT 양성 대상자 중 활성 또는 활동성미정 결핵 소견은 각각 6명(5.3%)과 3명(2.7%)에서 발견되었다. Acid-fast bacilli 염색, 배양 및 결핵에 대한 polymerase chain reaction을 포함한 미생물적 검사는 9명의 CT 양성 피험자 모두에서 음성이었다. CT 양성 피험자 9명은 경험적 항결핵약물 치료를 받았고, 이 9명 중 3명은 CXR 음성 소견이었다. 결론 IGRA 양성 의료 종사자에서 CT 검사는 무증상 결핵을 진단하는 데 도움을 주었다.

• Clinical and Experimental Pediatrics
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• 제57권8호
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• pp.351-356
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• 2014

Purpose: Among the many factors associated with acute intestinal mucosal infection, numerous studies have proposed the usefulness of fecal calprotectin. The aim of this study was to evaluate the usefulness of fecal calprotectin in the diagnosis of necrotizing enterocolitis (NEC). Methods: We collected 154 stool samples from 16 very low birth weight and premature newborns at the Konyang University Hospital neonatal intensive care unit or neonatal nursery. The stool samples were collected using the Calprest device, and the fecal calprotectin level was measured with the $B\ddot{U}HLMANN$ Calprotectin enzyme-linked immunosorbent assay kit. Results: Fecal calprotectin levels were significantly higher in the NEC group than in the non-NEC group (P=0.02). There was a significant positive linear relationship between the fecal calprotectin level and number of days after birth (P=0.00) in the gestational age <26 weeks group. There was a significant negative linear relationship between the calprotectin level and number of days after birth (P=0.03) in the gestational age ${\geq}26$ weeks and <30 weeks group. There was no difference in the calprotectin levels according to the type and method of feeding between the NEC and non-NEC groups. Conclusion: Fecal calprotectin levels were significantly increased in premature infants with NEC. The fecal calprotectin test is a noninvasive, easy, and useful tool for the diagnosis of NEC.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.524-528
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• 2001

The measurement of radiation response using simple and informative techniques would be of great value in studying the genetic risk following occupational, therapeutic, or accidental exposure to radiation. When patients receive radiation therapy, many suffer from side effects. Since each patient receives a different dose due to different physical conditions, it is important to measure the exact dose of radiation received by each patient to lessen the side effects. Even though several biological dosimetric systems have already been developed, there is no ideal system that can satisfy all the criteria for an idean dosimetric system, especially for low-dose radiation as used in radiation therapy. In this study, an SOS Chromotest of E. coli PQ37 was evaluated as a novel dosimeter for low-dose gamma-rays. E. coli PQ37 was originally developed to screen chemical mutagens using the SOS Chromotest-a colorimtric assay, based on the induction of ${\beta}$-galactosidase ue to DNA damage. The survival fraction of E. coli PQ37 decreased dose-dependently with an increasing dose of cobalt-60 gamma-rays. Also, a good linear correlation was found between the biological damage revealed by the ${\beta}$-galactosidase expression and the doses of gamma-rays. The expression of ${\beta}$-galactosidase activity that responded to low-dose radiation under 1 Gy was $Y=0.404+(0.089{\pm}0.3)D+(-0.018{\pm}0.16)D^2$ (Y, absorbance at 420 nm; D, Dose of irradiation) as calculated using Graph Pad In Plot and Excel. When a rabbit was fed with capsules containing an agar block embdded with E. coli PQ37 showed a linear response to the radiation doses. Accordingly, the results confirm that E. coli PQ37 can be used as a sensitive biological dosimeter fro cobalt-60 gamma-rays. To the best of our knowledge, this is the first time that a bacterium has been used as a biological dosimeter, especially for low-dose radiation.

• BMB Reports
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• 제38권5호
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• pp.584-590
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• 2005

Glucose 6-phosphate dehydrogenase (EC 1.1.1.49) was purified from Aspergillus aculeatus, a filamentous fungus previously isolated from infected tongue of a patient. The enzyme, apparently homogeneous, had a specific activity of $220\;units\;mg^{-1}$/, a molecular weight of $105,000{\pm}5,000$ Dal by gel filtration and subunit size of $52,000{\pm}1,100$ Dal by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The substrate specificity was extremely strict, with glucose 6-phosphate (G6P) being oxidized by nicotinamide adenine dinucleotide phosphate (NADP) only. At assay pH of 7.5, the enzyme had $K_m$ values of $6\;{\mu}m$ and $75\;{\mu}m$ for NADP and G6P respectively. The $k_{cat}$ was $83\;s^{-1}$. Steady-state kinetics at pH 7.5 produced converging linear Lineweaver-Burk plots as expected for ternary-complex mechanism. The patterns of product and dead-end inhibition suggested that the enzyme can bind NADP and G6P separately to form a binary complex, indicating a random-order mechanism. The enzyme was irreversibly inactivated by heat in a linear fashion, with G6P providing a degree of protection. Phosphoenolpyruvate (PEP), adenosinetriphosphate (ATP), and fructose 6-phosphate (F6P), in decreasing order, are effective inhibitors. Zinc and Cobalt ions were effective inhibitors although cobalt ion was more potent; the two divalent metals were competitive inhibitors with respect to G6P, with $K_i$ values of $6.6\;{\mu}m$ and $4.7\;{\mu}m$ respectively. It is proposed that inhibition by divalent metal ions, at low NADPH /NADP ratio, is another means of controlling pentosephosphate pathway.

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.1038-1042
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• 2009

Fifty-four cross-bred ((Landrace${\times}$Yorkshire)${\times}$Duroc) pigs (13.47${\pm}$0.03 kg average initial BW) were evaluated in a 42 d growth assay to determine the effects of the fermented soy product (FSP). The dietary treatments were: FSP 0 (corn-soybean basal diet), FSP 2.5 (FSP 0 amended with 2.5% FSP), and FSP 5 (FSP 0 amended with 5% FSP). The body weight at the end of the experiment increased linearly (p = 0.05) as the FSP levels in the diets increased. In addition, the ADG and G/F ratio also increased (linear effect, p = 0.06) as the levels of FSP increased. However, there was no effect of FSP on ADFI or DM digestibility (p>0.05). Furthermore, the N digestibility increased as the FSP levels increased (linear effect, p = 0.003), although the total protein concentration in the blood was not affected by FSP (p>0.05). Additionally, the albumin concentration was higher in pigs fed diets that contained 2.5% FSP than in pigs in the control group or the FSP 5 group (quadratic effect, p = 0.07). The creatinine concentrations were also evaluated at d 42 and found to be greater in pigs that received the FSP 2.5 diet (quadratic effect, p = 0.09). Moreover, the creatinine concentration increased linearly in response to FSP treatment (p = 0.09). Finally, although the BUN concentration on the final day of the experiment was greater in pigs that received the FSP 2.5 diet (quadratic effect, p = 0.10), there were no incremental differences in BUN concentrations among groups (p>0.05). Taken together, the results of this study indicate that feeding FSP to pigs during the late nursery phase improves growth performance and N digestibility.

• Mass Spectrometry Letters
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• 제5권4호
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• pp.104-109
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• 2014

Nonmedical use of prescription stimulants such as methylphenidate (MPH) and amphetamine (AP) by normal persons has been increased to improve cognitive functions. Due to high potential for their abuse, reliable analytical methods were required to detect these prescription stimulants in biological samples. A direct injection liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and implemented for simultaneous determination of MPH, AP and their metabolites ritalinic acid (RA) and 4-hydroxyamphetamine (HAP) in human urine. Urine sample was centrifuged and the upper layer ($100{\mu}L$) was mixed with $800{\mu}L$ of distilled water and $100{\mu}L$ of internal standards ($0.2{\mu}g/mL$ in methanol). The mixture was then directly injected into the LC-MS/MS system. The mobile phase was composed of 0.2% formic acid in distilled water (A) and acetonitrile (B). Chromatographic separation was performed by using a Capcell Pak MG-II C18 ($150mm{\times}2.0mm$ i.d., $5{\mu}m$, Shiseido) column and all analytes were eluted within 5 min. Linear least-squares regression with a 1/x weighting factor was used to generate a calibration curve and the assay was linear from 20 to 1500 ng/mL (HAP), 40-3000 ng/mL (AP and RA) and 2-150 ng/mL (MPH). The intra- and inter-day precisions were within 16.4%. The intra- and inter-day accuracies ranged from -15.6% to 10.8%. The limits of detection for all the analytes were less than 4.7 ng/mL. The suitability of the method was examined by analyzing urine samples from drug abusers.

• 대한의생명과학회지
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• 제15권1호
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• pp.55-60
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• 2009

Insect cells such as Spodoptera frugiperda Clone 9 (Sf9) cells are widely chosen as the host for heterologous expression of a mammalian sugar transport protein using the baculovirus expression system. Characterization of the expressed protein is expected to include assay of its function, including its ability to transport sugars and to bind inhibitory ligands such as cytochalasin B. It is therefore very important first to establish the transport characteristics and other properties of the endogenous sugar transport proteins of the host insect cells. However, very little is known of the transport characteristics of Sf9 cells, although their ability to grow on TC-100 medium strongly suggested the presence of endogenous glucose transport system. In order to investigate the substrate and inhibitor recognition properties of the Sf9 cell transporter, the ability of pentoses to inhibit 2-deoxy-D-glucose (2dGlc) transport was investigated by measuring inhibition constants $(K_i)$. To determine the time period over which of sugar into the Sf cells was linear, the uptake of 2dGlc 0.1mM extracellular concentration was measured over periods ranging from 30 seconds to 30 minutes. The uptake was linear for at least 2 minutes at the concentration, implying that uptake made over a 1 minute time course would reflect initial rates of the sugar uptake. The data have also revealed the existence of a saturable transport system for pentose uptake by the insect cells. The transport was inhibited by D-xylose and D-ribose, although not as effective as hexoses. However, L-xylose had a little effect on 2dGlc transport in the Sf9 cells, indicating that the transport is stereoselective. Unlike the human erythrocyte-type glucose transport system, D-ribose had a somewhat greater apparent affinity for the Sf9 cell transporter than D-xylose. It is therefore concluded that Sf9 cells contain an endogenous sugar transport activity that in some aspects resembled the human erythrocyte-type counterpart, although the Sf9 and human transport systems do differ in their affinity for cytochalasin B.

• Journal of Pharmaceutical Investigation
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• 제34권4호
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• pp.263-267
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• 2004

Branched and linear polyethylenimines (PEIs) have been studied as efficient and versatile agents for gene delivery in vitro and in vivo. PEIs exist in a linear or branched topology and are available in a wide range of molecular weight (Mw). Most studies have been done using PEIs with Mw higher than 10Kd. This study was aimed to test the transfection efficiency and the cell viability following gene delivery using PEI of Mw 2Kd, a relatively lower Mw cationic polymer. We used murine interleukin-2(mIL-2) plasmid DNA complexed with branched PEI 2Kd or 25Kd, and transfected them into a myoblast muscle cell line, C2C12. The cellular uptake of mIL-2 plasmid DNA was determined using quantitative polymerase chain reaction. RNA transcript levels were studied in the myoblast cells. Our results show that PEI 2Kd was as effective as PEI 25Kd in celluar gene delivery and transfection efficiency in C2C12 cells. Moreover, MTT assay indicated that PEI 2Kd/DNA complexes did not significantly reduce the cell viability regardless of N/P ratios. These results suggest that PEI of Mw 2Kd might play a role as effective and low toxic nonviral vector systems for muscular cell lines.