• 동의생리병리학회지
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• 제22권6호
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• pp.1518-1524
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• 2008

Ponciri Fructus (PF), the immature fruit of Poncirus trifoliata, has been used for treatment of constipation in Korean traditional medicine. It has been reported that PF has a prokinetic effect on gastrointestinal tract, but little is known about the effect on colonic contraction. The aim of this study was to investigate the effect of PF on spontaneous contractions of proximal and distal colon in rats. The aqueous extract of PF was centrifuged and filtered and its supernatant was used for in vitro motility study. The removed colon from rats was divided into proximal and distal segments. Each segment was mounted in a 10 ml organ bath and measured the change of the spontaneous contraction with increasing dose (1, 5, 10, 50, 100, 500, $1000{\mu}g/ml$) of PF extract administration. Also the effect of PF on the spontaneous contraction was measured under treatment of atropine, acetylcholine (Ach), and tetrodotoxin (TTX). PF increased the spontaneous phasic contraction of distal colon dose dependently, but there was no change in proximal colon. The contractile response induced by PF in distal colon was lower than that of Ach and was partially blocked by atropine ($10^{-6}M$). TTX increased the spontaneous contraction and it was reinforced with Ach addition. But the extract of PF had no or little contractile effect of TTX in colon. PF increased spontaneous contractions selectively in distal colon. The prokinetic effect of PF may be due to enhancement of cholinergic related excitatory neural system.

• 약학회지
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• 제50권5호
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• pp.301-307
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• 2006

A simple and sensitive high-performance liquid chromatographic method for quantitation of hydrochlorothiazide in human plasma was developed and bioavailability parameters of hydrochlorothiazide were assessed in Korean healthy male volunteers. Caffeine was used as an internal standard. Hydrochlorothiazide and internal standard in plasma sample were extracted using tert-butylmethylether (TBME). A centrifuged upper layer was then evaporated and reconstituted with mobile phase of acetonitrile-25 mM phosphate buffer (20/80, pH 2.5). The reconstituted samples were injected into a Luna C18 column $(250{\times}4.6\;mm,\;5{\mu}m)$ at a flow-rate of 1.0 ml/min. The wavelength was set at 230 nm and no endogenous substances were found to interfere, A linear relationship for hydrochlorothiazide was found in the range of $10{\sim}300\;ng/ml$. The lower limit of quantitation (LLOQ) was 10 ng/ml with acceptable precision and accuracy. Assayed in plasma, the intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. Main pharmacokinetic parameters of 50mg of hydrochlorothiazide were revealed as follows: $AUC_t\;1761{\pm}509.0\;ng{\cdot} hr\;ml,\;C_{max}\;296.5{\pm}95.5\;ng/ml,\;T_{max}\;1.94{\pm}0.85hr,\;K_{el}\;0.12{\pm}0.04\;hr^{-1}\;and T_{12}\;6.81{\pm}2.92\;hr.\;C_{max}\;and\;T_{max}$ were in accordance with the values $(270{\sim}350\;ng/ml\;and\;1.9{\sim}2.7\;hr)$ of Caucasian.

• Food Science and Biotechnology
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• 제17권5호
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• pp.925-930
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• 2008

Norovirus has become the most common cause of human gastroenteritis in developed countries. Detection procedures of foodborne viruses from foods require several steps. The concentration step using polyethylene glycol (PEG) is time-consuming and the detection efficiency of reverse transcription-polymerase chain reaction (RT-PCR) is affected by inhibitors from food components. In this study, a rapid detection method based on buoyant density centrifugation was developed to replace the time-consuming chloroform-polyethylene glycol-Tris Tween method. Feline calicivirus that belongs to the family Caliciviridae was used as a surrogate model for norovirus. After artificial inoculation of feline calcivirus (FCV) to oyster and lettuce, 830 ${\mu}L$ of homogenized sample suspension was layered on the top of 670 ${\mu}L$ 20% percoll and centrifuged. Then RNA extraction step was proceeded with the supernatant. By varying several physical conditions, the detection limits were lowered to $2.4{\times}10^2$ PFU per 1 g in oyster and $2.4{\times}10^0$ PFU per 1 g in lettuce. The protocol obtained in this study could be used to develop new detection method for norovirus in foods.

• Toxicological Research
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• 제14권3호
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• pp.357-363
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• 1998

The teratogenic potential of the anticonvulsant drug phenytoin (PHT) has been well documented both in the human and in the experimental animals. However there are few reports on the effects of PHT on embryonic development in rats in vitro. The present study was performed to evaluate the teratogenic effects of PHT using whole-embryo culture system in rats. Sprague-Dawley rat embryos were explanted on gestational day (GD) 9.5 and cultured for 48 hrs in the immediately centrifuged and heat-inactivated rat serum containing 0,25,50, or $100{\mu}g$ PHT/mL. At the end of culture period the embryos were scored for morphological development according to the procedure of Van Maele-Fabry, and their total protein contents were determined. At 100 ${\mu}$g/mL of culture medium. PHT caused significant reduction in developmental score and protein content of embryos and a high incidence morphological abnormalities (100%). Characteristic malformations included altered yolk and embryonic circulation, craniofacial hypoplasia, neural tube schisis, branchial arch defects, abnormal ratation, and limb bud hypoplasia, among others. There were no adverse effects on embryonic growth and development at concentrations of 25 and 50 ${\mu}$g /mL of culture medium. The results indicated that the dysmorphogenic effect of PHT on cultured embryos is due to a direct interference with embryonic development.

• 대한수의학회지
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• 제29권3호
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• pp.253-262
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• 1989

This study was performed to investigate the patterns of progesterone secretion after induction of estrus in premature, metestrous and anestrous bitches. A total of 22 bitches were used. Of them 18 bitches were treated with hormone to induced estrus and 4 bitches were untreated and served as controls. Estrus was induced with $PGF_{2{\alpha}}$, estrone, estradiol-$17{\beta}$, PMSG and HCG(Treatment A), and with PMSG and HCG(Treatment B). Blood samples were collected via the cephalic vein at 2 to 5 days interval. Blood samples were centrifuged (1,200g, 10min.) within 30 minutes after collection and plasma was stored at $-20^{\circ}C$ until analyzed for the progesterone concentrations. Plamsa progesterone concentrations were measured by radioimmunoassay. The results of estrous induction were determined by estrous signs, ovarian response, egg recovery and progesterone patterns. The results obtained were as follows; 1. All bitches in treatment A showed estrous signs, however the ovarian response and egg recovery were not detectable and the levels of progesterone were nearly same as before. 2. In the treatment B, premature and metestrous bitches showed only estrous signs, however 5 of 7 anestrous bitches (71.4%) showed estrous signs, ovarian response and changes of progesterone levels. In conclusion, clinical estrous behavior can be induced during any phase of the estrous cycle, but ovulation should be induced only if induction occur approximately 4 months or more after the previous estrus.

• 분석과학
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• 제30권2호
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• pp.57-67
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• 2017

This study was conducted to develop an analytical technique for determination of chlorite and chlorate concentrations in fresh-cut food and dried fish products by an ion chromatography/conductivity detection method using a hydroxide mobile phase. Deionized water was added to homogenized samples, which were then extracted by ultrasound extraction and centrifuged at high speed (8,500 rpm). Subsequently, a Sep-Pak tC18 cartridge was used to purify the supernatant. Chlorite and chlorate ions were separated using 20 mM KOH solution as the mobile phase and Dionex IonPac AS27 column as the stationary phase. Ethylenediamine was used as sample preservative and dibromoacetate was added to adjust for the disparity in extraction efficiencies between the food samples. The method detection limit) for chlorite and chlorate were estimated to be 0.2 mg/kg and 0.1 mg/kg, respectively, and the coefficient of determination ($r^2$) that denotes the linearity of their calibration curves were correspondingly measured to be 0.9973 and 0.9987. The recovery rate for each ion was 92.1 % and 96.3 %, with relative standard deviations of 7.47 % and 6.18 %, respectively. Although neither chlorite nor chlorate was detected in the food samples, the analytical technique developed in this study may potentially be used in the analysis of disinfected food products.

• 대한임상검사과학회지
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• 제39권3호
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• pp.156-160
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• 2007

We evaluated the newly developed plastic sodium citrate tubes for routine coagulation test by direct comparison with glass citrate theophylline adenosine dipyridamole (CTAD) tubes. Blood was drawn from 100 patients into glass CTAD tubes and plastic sodium citrate tubes. After collection, samples were centrifuged at 1500 ${\times}$g for 15 min at $22^{\circ}C$. Prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen were measured by using the Coagrex-800 (IRC, Japan). We used comparison plot by linear regression model and difference plot graphs to compare the results of the independent measurements of PT, aPTT, fibrinogen between glass CTAD tubes and plastic sodium citrate tubes. On the comparison study between glass CTAD tubes and plastic sodium citrate tubes, the correlation coefficients (R) were 0.99 for PT, 0.97 for aPTT and 0.97 for fibrinogen. This results implicated good correlation of each parameter between two tubes. Although the difference plot graph analysis showed statistically significant differences between glass and plastic tubes for PT, aPTT and fibrinogen, the range of difference was acceptable according to the CLSI/NCCLS guideline. The plastic sodium citrate tubes showed good correlation with the glass CTAD tubes, so it can substitute glass citrate tube for routine coagulation tests.

• 한국식품과학회지
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• 제49권6호
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• pp.591-598
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• 2017

This study aimed to evaluate the measurement uncertainty for the quantitative determination of chlorite and chlorate in ready-to-eat fresh-cut vegetables using ion chromatography with a hydroxide-selective column. One gram of the homogenized sample in deionized water was sonicated and centrifuged at 8,500 rpm. The supernatant was purified by passing it through a Sep-Pak tC18 cartridge, followed by chromatographic determination using a Dionex IonPac AS27 column. The linearity of the calibration curves, recovery, repeatability, and reproducibility of the method were satisfactory. The method detection limit was estimated to be approximately 0.5 mg/kg. Each uncertainty component was evaluated separately, and the combined and expanded uncertainty values were calculated at the 95% confidence level. The measured concentrations for 3 mg/kg of chlorite and chlorate standard materials were $3.18{\pm}0.32$ and $3.10{\pm}0.42mg/kg$, respectively. These results confirmed the reliability of the developed method for measuring the two chlorine-based oxyanions in fresh-cut vegetables.

• 한국미생물·생명공학회지
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• 제18권6호
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• pp.660-661
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• 1990

Autographa californica nuclear polyhedrosis virus(AcNPV) L-1주의 extracellular nonoccluded virion (NOV)을 보관하는 방법을 연구하였다. AcNPV NOVs을 Spodoptera frugiperda cell line에 감염을 시킨 후에 배양액을 원심분리하여 AcNPV NOVs가 들어 있는 상등액을 취하여 $4^{\circ}C$에서 약 11년간 보관하였다. 보관되어 있는 AcNPV NOV을 Spodoptera frugiprda cell line에 재감염하여 관찰한 결과 NOVs의 감염과 증식이 정상적이었으며, NOV의 역가가 $8.9 \times 10^7$pfu/ml에서 $3.8 \times 10^5$pfu/ml로 떨어졌을 뿐이다. 또한 HindIII와 EcoRI 제한효소로 AcNPV genome DNA을 절단하여 패턴을 조사한 결과 DNA제한 효소 패턴은 변하지 않았다. 즉 AcNPV NOVs는 $4^{\circ}C$에서 보존하면 10년 이상 안정성이 있고, 취급이 용이하다는 것을 알 수 있었다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 춘계학술발표대회
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• pp.42-42
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• 2001

The objective of this study was to assess the development of porcine follicular oocytes fertilized by ICSI. Cumulus-oocyte-complexes (COCs) were collected by aspiration from follicles of 2-7 mm in diameter from a local slaughterhouse ovaries. Oocytes matured for 40-44 h were centrifuged at 12,000g for 6 min and then injected with sperm prepared by swim-up procedure in the presence or absence of 5 mM dithiothreitol (DTT). Injected oocytes were cultured in NCSU 23 medium during 6 to 8 days. IVF controls were compared to those of resulting embryos. The results obtained were as. follow: 1, The rates of cleavage and development rates into blastocyst by ICSI were not significantly (P<0.05) different between with (53.0% and 19.7%) or without (48.3% and 23.8%) centrifugation, respectively. 2. The cleavage and developmental rates to blastocyst after ICSI with or without 5mM DTT treated-sperm were not significantly (P<0.05) different (60.4% vs 16.4% and 48.5% vs 22.2%, respectively). 3. The cleavage and the developmental rates to blastocyst were not significantly (P<0.05) different between the zygotes obtained by IVF (51.8% vs. 22.4%) and ICSI (51.4% vs. 21.6%). 4. The number of blastomere in blastocyst stages after IVF or ICSI was not significantly different (46.7 $\pm$2.9 and 41.9$\pm$4.6).