A Colorimetric Microplate Assay Method for High Throughput Analysis of Lipase Activity

Choi, Suk-Jung,Hwang, Jung-Min,Kim, Sung-Il Korean Society for Biochemistry and Molecular Biol 2003 Journal of biochemistry and molecular biology Vol.36 No.4

The present work describes a colorimetric microplate assay for lipase activity based on the reaction between 5,5'-dithiobis(2-nitro benzoic acid) (DTNB) and the hydrolysis product of 2,3-dimercapto-1-propanol tributyrate (DMPTB). Reaction mixtures containing DTNB, DMPTB, and lipase were prepared in microplate wells, and the absorbance at 405nm was recorded after incubation at $37^{\circ}C$ for 30 min. A linear relationship was obtained in the range of 0.1-1 U of lipase activity by this method. The reaction conditions were also optimized for the range of 0.01-0.1 U or 1-10 U. When assaying crude tissue extracts, the reaction of DTNB with non-specific reducing agents created a major source of error. However, this error was corrected by the use of blank samples that did not contain DMPTB.

경막외 마취시 Clonidine 과 Epinephrine 첨가에 따른 마취연장효과의 비교

최영석,이미경,이일옥,윤석민,임상호,김난숙 대한마취과학회 1993 Korean Journal of Anesthesiology Vol.26 No.2

Epidural clonidine is reported to produce analgesia in humans. To investigate the analgesic effect and prolongation of epidural and spinal anesthesia, we mixed 0.2mg epinephrine, 150 mcg clonidine, or 1 cc normal saline with 0.5% bupivacaine and compared the hemodynamie and analgesic effects of each drug. Heart rate and blood pressure were checked before, during and after anesthesia. Sensory level was checked by pin-prick method. The results were as follows; 1) The analgesia onset time and the time to highest level of sensory loss was most rapid in the epinephrine group. 2) The two segment regression time was significantly prolonged in the epinephrine group. 3) The analgesia duration was significantly prolonged in the clonidine and epinephrine group. 4) Although the heart rate gradually decreased over 60 min. After injection of each drug, there was no significant change between the groups. 5) Blood pressure decreased over 20-30 min. After injection of each drug, but there was no significant change between the groups.

A Colorimetric Microplate Assay Method for High Throughput Analysis of Lipase Activity

Choi, Suk-Jung,Hwang, Jung Min,Kim, Sung Il 한국생화학분자생물학회 2003 BMB Reports Vol.36 No.4

The present work describes a colorimetric microplate assay for lipase activity based on the reaction between 5,5'-dithiobis(2-mitro benzoic acid)(DTNB) and the hydrolysis product of 2,3-dimercapto-1-propanol tributyrate (DMPTB). Reaction mixtures containing DTNB, DMPTB, and lipase were prepared in microplate wells, and the absorbance at 405nm was recorded after incubation at 37℃ for 30 min. A linear relationship was obtained in the range of 0.1-1 U of lipase activity by this method. The reaction conditions were also optimized for the range of 0.01-0.1 U or 1-10 U. When assaying crude tissue extracts, the reaction of DTNB with non-specific reducing agents created a major source of error. However, this error was corrected by the use of blank samples that did not contain DMPTB.

Effects of Supercritical Carbon Dioxide Treatment on Meat Quality and Sensory Evaluation in Soy Sauce and Hot-pepper Paste Marinated Pork

Choi, Young Min,Lee, Sang Hoon,Choe, Jee Hwan,Kim, Kyoung Heon,Rhee, Min Suk,Kim, Byoung Chul Korean Society for Food Science of Animal Resource 2013 한국축산식품학회지 Vol.33 No.5

The objective of this study was to investigate the effects of supercritical carbon dioxide (SC-$CO_2$) treatment on meat quality and sensory evaluation of marinated pork. Meat marinated in two traditional Korean marinades, soy sauce and hot-pepper paste, and raw marinated meat were then treated with 7.4, 12.2, or 15.2 MPa $CO_2$ at $31.1^{\circ}C$for 10 min. The SC-$CO_2$ treatments had no effect on the meat pH (p>0.05) or Warner-Bratzler shear force (p>0.05). There was no significant difference (p>0.05) in the total loss (sum of treatment loss and cooking loss) between the control and SC-$CO_2$ treated samples at 15.2 MPa (soy sauce marinated pork: 21.78 vs. 18.97%; hot-pepper marinated pork: 21.61 vs. 18.01%). After the SC-$CO_2$ treatment, lighter surface colors were observed in the treatment samples compared to those of the control samples (p< 0.001). However, tasting panelists were unable to distinguish a difference in color or in overall acceptability of the control and treatment (p>0.05). In the case of soy sauce marinated pork, when SC-$CO_2$ applied at 15.2 MPa and $31.1^{\circ}C$for 10 min, treatment samples showed a tenderer meat than the control samples. Therefore, the SC-$CO_2$ treatment conditions had no adverse effects on the sensory quality characteristics of the marinated meat products.

성인에서 기관내삽관을 위한 Pipecuronium 일회 정주 적정 용량

최영석,윤석민,임상호,이미경,박영철,류태간 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.33 No.3

Background : Studies in animals suggest that pipecuronium dose not induce hemodynamic chan-ges related to histamine release or to an effect on the autonomic nervous system. Therefore the effects of bolus administration of large doses of pipecuronium, up to 0.20 mg/kg, on the intubation condition, onset and duration of neuromuscular blockade, heart rate and blood pressure were studied during fentanyl- nitrous oxide anesthesia. Method : Forty adults were randomly assigned to receive a bolus injection of either 0.05, 0.10, 0.15, 0.20 mg/kg of pipecuronium. Neuromuscular blockade was measured using mechanomyographic activity of the adductor pollicis muscle after supramaximal stimulation of the ulnar nerve. Four subgroups of 10 patients received pipecuronium doses of 0.05, 0.10, 0.15 and 0.20 mg/kg, respectively, as an intubating dose. Results : The times of onset and clinical duration(mean sem) after each dose were as follows: 0.05 mg/kg, 2.98 0.42 and 41.5 2.42 min; 0.10 mg/kg, 1.54 0.06 and 82.9 7.48 min; 0.15 mg/kg, 1.41 0.14 and 124.8 13.1 min; 0.20 mg/kg, 1.12 0.05 and 187.1 12.8 min. The intubation condition, time of onset and duration after doses of 0.05 mg/kg were significantly different from values after the higer doses. The duration was increased with dose-increments. No dose-related changes in heart rate or blood pressure were observed. Conclusion : The authors conclude that dose of 0.10 mg/kg and over has good intubation condition clinically and large bolus dose of pipecuronium can be safely used with a significantly prolonged duration of action without hemodynamic change. (Korean J Anesthesiol 1997; 33: 453∼457)

함산소불화 활성탄소섬유를 이용한 저농도 크롬이온의 흡착 특성

김민지 ( Min Ji Kim ),정민정 ( Min Jung Jung ),최석순 ( Suk Soon Choi ),이영석 ( Young Seak Lee ) 한국공업화학회 2015 공업화학 Vol.26 No.4

In this work, activated carbon fibers (ACFs) were oxyfluorinated and their adsorption ability for the low concentration of hexavalent chromium in an aqueous solution was investigated. The pore structure and surface properties of ACFs were examined by BET and X-ray Photoelectron Spectroscopy (XPS), respectively. Due to the oxyfluorination treatment, the content of (C-O) bond on ACFs surface which influences the adsorption capacity for heavy metal ions increased largely, resulting that Cr6+ adsorption equilibrium reached quickly within 10 min. In addition, the maximum removal efficiency at the initial Cr6+ concentration of 20 ppm was observed, which is a 100% improvement compared to that of non-treated ACFs. These results suggest that the oxyfluorination of ACFs can be applied as a good surface treatment for the effective adsorption of the low concentration of Cr6+.

Effects of Supercritical Carbon Dioxide Treatment on Meat Quality and Sensory Evaluation in Soy Sauce and Hot-pepper Paste Marinated Pork

Young Min Choi,Sang Hoon Lee,Jee Hwan Choe,Kyoung Heon Kim,Min Suk Rhee,Byoung Chul Kim 한국축산식품학회 2013 한국축산식품학회지 Vol.33 No.5

The objective of this study was to investigate the effects of supercritical carbon dioxide (SC-CO2) treatment on meat quality and sensory evaluation of marinated pork. Meat marinated in two traditional Korean marinades, soy sauce and hot-pepper paste, and raw marinated meat were then treated with 7.4, 12.2, or 15.2 MPa CO2 at 31.1oC for 10 min. The SC-CO2 treatments had no effect on the meat pH (p>0.05) or Warner-Bratzler shear force (p>0.05). There was no significant difference (p>0.05) in the total loss (sum of treatment loss and cooking loss) between the control and SC-CO2 treated samples at 15.2 MPa (soy sauce marinated pork: 21.78 vs. 18.97%; hot-pepper marinated pork: 21.61 vs. 18.01%). After the SC-CO2 treatment, lighter surface colors were observed in the treatment samples compared to those of the control samples (p< 0.001). However, tasting panelists were unable to distinguish a difference in color or in overall acceptability of the control and treatment (p>0.05). In the case of soy sauce marinated pork, when SC-CO2 applied at 15.2 MPa and 31.1oC for 10 min, treatment samples showed a tenderer meat than the control samples. Therefore, the SC-CO2 treatment conditions had no adverse effects on the sensory quality characteristics of the marinated meat products.

Dose-linear pharmacokinetics of oleanolic acid after intravenous and oral administration in rats

Jeong, Dong Won,Kim, Young Hoon,Kim, Hui Hyun,Ji, Hye Young,Yoo, Sun Dong,Choi, Won Rack,Lee, Soo Min,Han, Chang-Kyun,Lee, Hye Suk WILEY PUBLISHERS 2007 BIOPHARMACEUTICS AND DRUG DISPOSITION Vol.28 No.2

<P>The pharmacokinetics of oleanolic acid was evaluated in vitro and in vivo. From Caco-2 cell permeation studies, oleanolic acid was a low permeability compound with no directional effects, suggesting a low in vivo absorption mediated by a passive diffusion. Oleanolic acid was metabolically unstable following incubation with rat liver microsomes in the presence of NADPH. After intravenous injection at doses of 0.5, 1 and 2 mg/kg doses, oleanolic acid showed dose-linear pharmacokinetics as evidenced by unaltered CL (28.6–33.0 ml/min/kg), V<SUB>ss</SUB> (437–583 ml/kg), dose-normalized AUC (16.0–17.9 µg min/ml based on 1 mg/kg) and t<SUB>1/2</SUB> (41.9–52.7 min). Following oral administration of oleanolic acid at doses of 10, 25 and 50 mg/kg, T<SUB>max</SUB>, t<SUB>1/2</SUB>, dose-normalized C<SUB>max</SUB> (66–74 ng/ml based on 25 mg/kg) and dose-normalized AUC (5.4–5.9 µg min/ml based on 25 mg/kg) were comparable between 25 and 50 mg/kg dose, but the plasma concentrations at 10 mg/kg dose were not measurable as they were below the limit of quantitation (2 ng/ml). The absolute oral bioavailability was 0.7% for oral doses of 25 and 50 mg/kg. The extent of urinary excretion was minimal for both i.v. and oral doses. The very low oral bioavailability of oleanolic acid could be due to a poor absorption and extensive metabolic clearance. Copyright © 2007 John Wiley & Sons, Ltd.</P>

Sustained-release praziquantel tablet : pharmacokinetics and the treatment of clonorchiasis in beagle dogs

Hong, Sung-Tae,Lee, Sang Hyup,Lee, Seung-Jin,Kho, Weon-Gyu,Lee, Mejeong,Li, Shunyu,Chung, Byung-Suk,Seo, Min,Choi, Min-Ho 梨花女子大學校 藥學硏究所 2003 藥學硏究論文集 Vol.- No.12

Praziquantel is rapidly absorbed and secreted; and thus fractional doses are recommended for the treatment of cestode and trematode infections. In the present study, we developed a new praziquantel tablet formula allowing sustained-release (SRP). In vitro dissolution of SRP tablets showed that praziquantel at 300 ㎎/tablet combined with hydroxypropyl methylcellulose dissolved completely at a constant rate over 10 h, whereas the conventional praziquantel tablet (PZQ) was only 40% dissolved. Pharmacokinetic studies in dogs confirmed that SRP was absorbed more slowly than PZQ. The mean value of the area under the concentration/time curve from 0 h to the final observation time, the maximum concentration in serum, and the time of maximum concentration in serum for SRP were 3.471.500 ng/min for 0.25 ㎖, 10,300 ng for 0.25 ㎖, and 192 min. while the values for PZQ were 688,600 ng/min for 0.25㎖, 2,500 ng for 0.25㎖, and 135 min. The cure rate in dogs with a heavy infection (500 metacercariae) treated with a single dose of SRP (150 ㎎/tablet) at 50 ㎎/㎏ was 80%, while in dogs treated with a single dose of SRP (300 ㎎/tablet) at 30 mg/kg it was 60%, and the cure rate with PZQ was 20%. In each case. the egg reduction rate was similar (over 90%). No abnormal liver functions or hepatic or renal pathologies were observed in dogs administered with SRP at 30 ㎎/㎏. The SRP tablet showed sustained release and slow absorption; and it had an improved anthelmintic efficacy against Clonorchis sinensis in experimental dogs. compared with conventional praziquantel.

하악 제1대구치의 치근 만곡에 영향을 주는 요인

최항문,이원진,허민석,이삼선,김정화,최순철,박태원 대한구강악안면방사선학회 2006 Imaging Science in Dentistry Vol.37 No.1

Purpose : To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. Materials and Methods : Twenty six 1st graders whose mandibular 1st molars just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal plane angle, gonial angle, and gonion-gnathion distance (Go-Gn distance) were measured. In panoramic radio graph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. Results : The Pearson correlation coefficient between curved angle and longitudinal variations of occlusal plane-tooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p<0.05). There was no significant correlation between elongated root length and longitudinal variations of all variables. The resulting regression equation was Y=10.209+0.208X_(1)+0.745X_(2) (Y: root angle, X_(1): variation of occlusal plane-tooth axis angle, X_(2): variation of ramus-occlusal plane angle). Conclusion: It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane. (Korean J Oral Maxillofac Radiol 2006; 36 : 55-62)