• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.3
• /
• pp.297-305
• /
• 1998

This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.6
• /
• pp.551-556
• /
• 2002

We have experimentally evaluated the content of thyroid hormones (THs), the growth and activity of larval rockfish (Sebastes schiegeli) born from parturient mother fish injected with 20 $\mu$g/g BW of 3,5,3-triiodo-L-thyronine ($T_{3}$). There was no difference of L-thyroxine ($T_{4}$) levels between controls (sham control and control) and $T_{3}$ groups in yolk-sac larvae just born from broodstock, while $T_{3}$level of $T_{3}$ group was significantly increased compared with controls. In addition, the both larval $T_{3}$ and $T_{4}$ levels in $T_{3}$ group were always higher than those of control during experimental period. Also, there were significant differences in the development of larvae from the two groups. The larval growth in total length and body weight according to the elapsed days after parturition showed the linear and curve equations, respectively, and the slopes of $T_{3}$ group were significantly higher than those of control. The survival rate of larvae in $T_{3}$ group was higher than that of control. Although the survival rate in $T_{3}$ group under the condition of starvation was significantly depressed compared with the control, larval swimming index in $T_{3}$ group was higher than control. Finally, these findings suggest that the exogenous $T_{3}$ could be transferred into hatched larvae in parturient rockfish by maternal injection, and subsequently the exogenous hormone could play some roles on physiological metabolism of larvae after parturition and may confer a distinct advantage to the fragile larvae during the early developmental stage.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.220-220
• /
• 2013

Surface-normal transmission electro-absorption modulator (EAM) are attractive for high-definition (HD) three-dimensional (3D) imaging application due to its features such as small system volume and simple epitaxial structure [1,2]. However, EAM in order to be used for HD 3D imaging system requires uniform modulation performance over large area. To achieve highly uniform modulation performance of EAM at the operating wavelength of 850 nm, it is extremely important to remove the GaAs substrate over large area since GaAs material has high absorption coefficient below 870 nm which corresponds to band-edge energy of GaAs (1.424 eV). In this study, we propose and experimentally demonstrate a transmission EAM in which highly selective backside etching methods which include lapping, dry etching and wet etching is carried out to remove the GaAs substrate for achieving highly uniform modulation performance. First, lapping process on GaAs substrate was carried out for different lapping speeds (5 rpm, 7 rpm, 10 rpm) and the thickness was measured over different areas of surface. For a lapping speed of 5 rpm, a highly uniform surface over a large area ($2{\times}1\;mm^2$) was obtained. Second, optimization of inductive coupled plasma-reactive ion etching (ICP-RIE) was carried out to achieve anisotropy and high etch rate. The dry etching carried out using a gas mixture of SiCl4 and Ar, each having a flow rate of 10 sccm and 40 sccm, respectively with an RF power of 50 W, ICP power of 400 W and chamber pressure of 2 mTorr was the optimum etching condition. Last, the rest of GaAs substrate was successfully removed by highly selective backside wet etching with pH adjusted solution of citric acid and hydrogen peroxide. Citric acid/hydrogen peroxide etching solution having a volume ratio of 5:1 was the best etching condition which provides not only high selectivity of 235:1 between GaAs and AlAs but also good etching profile [3]. The fabricated transmission EAM array have an amplitude modulation of more than 50% at the bias voltage of -9 V and maintains high uniformity of >90% over large area ($2{\times}1\;mm^2$). These results show that the fabricated transmission EAM with substrate removed is an excellent candidate to be used as an optical shutter for HD 3D imaging application.

• Clinical and Experimental Pediatrics
• /
• v.49 no.7
• /
• pp.800-804
• /
• 2006

Necrotizing enterocolitis(NEC) is the most common life-threatening surgical emergency in neonates, and remains a major cause of morbidity and mortality. In addition to conventional laparotomy, intraperitoneal drains have been used for the treatment of perforated NEC, especially in extremely low birth weight(ELBW) infants. We report a case of perforated NEC with bacterial peritonitis in an ELBW infant managed with primary peritoneal drainage(PD) without further need for surgery. To our knowledge, this is the first documented Korean case of an ELBW infant where PD was used as primary treatment for perforated NEC. Primary PD is effective and safe in ELBW infants with perforated NEC; although it is not considered a definitive procedure, it should be considered in all cases where infants are too unstable to tolerate anesthesia and surgery.

• Journal of Photoscience
• /
• v.11 no.3
• /
• pp.115-120
• /
• 2004

For the expression study of antioxidant isoenzyme genes in rice (Oryza sativa L.) plants, extensive searches for genes of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) isoforms were performed through the GenBank database. The genes for two cytosolic and one plastidic CuZn-SOD, one Fe-SOD, two Mn-SOD, two cytosolic and two chloroplastic (stromal and thylakoid) APX, and three CAT isoforms were available in japonica-type rice. These isoforms were named as cCuZn-SOD1, cCuZn-SOD2, pCuZn-SOD, Fe-SOD, Mn-SOD1, Mn-SOD2, cAPXa, cAPXb, Chl_sAPX, Chl_tAPX, CATa, CATb, and CATc, respectively. Since they shared a high degree of homology in the nucleotide and amino acid sequences, the gene-specific primers for the genes were designed directly from their full-length cDNAs found in the database except for the CATa gene. These primers were used in the RT-PCR analysis to investigate the differential expression of antioxidant isoenzyme genes in rice plants from the seeds irradiated with low doses (2, 4, 8, and 16 Gy) of gamma-radiation. The gammairradiation slightly increased the transcripts of pCuZn-SOD, while those of Fe-SOD, cAPXb, and CATb decreased. However, no substantial differences were observed in the expression of all the isoenzyme genes between the control and irradiated groups. In this study, gene specific primers for thirteen SOD, APX and CAT isoenzymes were constructed from the full-length cDNAs. The results of RT-PCR analysis obtained by using these primers suggests that the expression levels of SOD, APX, and CAT isoenzyme genes in rice seedlings were hardly affected by gamma-irradiation at the seed stage.

• Journal of Preventive Medicine and Public Health
• /
• v.39 no.2
• /
• pp.123-129
• /
• 2006

Objectives : The incidence of colorectal cancer increased greatly among the elderly in Korea, but the relationship between smoking and colon cancer remains controversial. Few studies have targeted Asian elderly people. We analyzed the smoking status, the amount smoked, and the smoking duration as risk factors of colorectal cancer to determine their association and causality. Methods: The cohort members (n=14, 103) consisted of 4,694 males and 9,409 females, and they were derived from the Korea Elderly Phamacepidemilogic Cohort (KEPEC), which was a population-based dynamic cohort. They were aged 65 years or more and they lived in Busan Metropolitan City between from 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). The baseline information was surveyed by a self-administered mailed questionnaire; after 8.7 person-years of mean follow up period, 100 cases of colorectal cancer occurred. The adjusted relative ratio (aRR) of smoking status, the smoking amount and the smoking duration were calculated from the Cox's proportional hazard model with the never-smokers as a reference group and the Cox model controlled for age, gender, precancerous lesions of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI. Results : Compared with the never smokers, the aRRs were 2.03 (95% CI=1.02-4.03) and 1.36 (95% CI=0.80-2.32) for the ex-smokers and current smokers, respectively. Statistical significant trends were not observed for the dose-relationship among the elderly, either for the mean daily amount smoked (p for trend=0.28) or for the total amount (p for trend=0.15). Still, the aRRs were 1.51 (95% CI=0.97-2.34) for the elderly who smoked less than 40 years and 2.35 (95% CI=1.16-4.74) for the elderly who had 40 years or more of smoking (p for trend=0.06). Smokers who started smoking before the age 20 had an increased aRR of 2.15 (95% CI=1.17-3.93) compared to the never smokers. Conclusions : After controlling for age, gender, precancerous lesion of CRC, medication history of NSAIDs & antibiotics, the alcohol drinking status and BMI, smoking increases the risk of colorectal cancer among elderly people. The age when starting smoking is also important.

• Journal of Life Science
• /
• v.26 no.2
• /
• pp.164-173
• /
• 2016

Isotocin (IT), a nonapeptide homolog of oxytocin in mammals, has been suggested to be involved in physiological processes including social behaviors, stress responses, and osmoregulation in teleost fish. To study its structure and function, the gene encoding the IT precursor was cloned from the genomic DNA and brain cDNA of the cinnamon clownfish, Amphiprion melanopus. The IT precursor gene consists of three exons separated by two introns, and encodes an open reading frame of 156 amino acid (aa) residues, comprising a putative signal peptide of 19 aa, a mature IT protein of 9 aa, a proteolytic processing site of 3 aa, and 125 aa of neurophysin. Tissue-specific analysis of the IT precursor transcript indicated its expression in the brain and gonads of A. melanopus. To examine its osmoregulatory effects, the salinity of the seawater (34 ppt) used for rearing A. melanopus was lowered to 15 ppt. Histological analysis of the gills indicated the apparent disappearance of an apical crypt on the surface of the gill lamella of A. melanopus, as pavement cells covered the surface upon acclimation to the lower salinity. The level of Na⁺/K^+-ATPase activity in the gills was increased during the initial stage of acclimation, followed by a decrease to its normal level, suggesting its involvement in osmoregulation and homeostasis. The only slight increase in the level of IT precursor transcript in the A. melanopus brain upon low-salinity acclimation suggested that IT played a minor role, if any, in the process of osmoregulation.

• Korean Journal of Organic Agriculture
• /
• v.22 no.3
• /
• pp.423-434
• /
• 2014

This study was conducted to investigate the hypoglycemic effects and the production conditions of the Korean organic native rice cultured by Ganoderma lucidum. The broth culture of Ganoderma lucidum, the innoculation and culture of Ganoderma lucidum to the Korean organic native rice, and the oral administration of the Korean organic native rice cultured by Ganoderma lucidum to the streptozotocin-induced diabetic rats, were carried out. Then, the blood glucose level, the serum total cholesterol and triglyceride, and the activities of alanine aminotransferase and aspartate aminotransferase, were analyzed. The pH 4.5 at $30^{\circ}C$ was the optimal condition of the broth culture of Ganoderma lucidum. When the physical shape and the smell of the produced rice were considered, the optimal conditions to produce the Korean organic native rice cultured by Ganoderma lucidum, were the seeding of Ganoderma lucidum to Korean organic native rice in the rate of 7.5% weight, and the culture period of 9days at $28^{\circ}C$. In streptozotocin-induced diabetic rats, the blood glucose level of the dieted group by the Korean organic native rice cultured by Ganoderma lucidum for 2 weeks, were significantly decreased when compared with the control. And, the levels of the total cholesterol and triglyceride in serum were ranked less than those of the control. Also, in streptozotocin-induced diabetic rats, the activities of alanine aminotransferase and aspartate aminotransferase in the serum of the dieted group by the Korean organic native rice cultured by Ganoderma lucidum for 2 weeks, were lower than those of the control.

• Current Research on Agriculture and Life Sciences
• /
• v.4
• /
• pp.114-118
• /
• 1986

The study was conducted to find out the gene effects on litter size and birth weights in mice with 362 progenies from full-diallel crosses of four lines of BALB/c, CBA, C3H and C57BL. The progenies were farrowed at the Experimental Animal Farm, College of Agriculture, Kyungpook National University in November, 1984, and data were analyzed into general combining ability, specific combining ability and reciprocal effects with Griffing's model. General combining ability effects estimated in line-crosses were -0.4163~0.3337 for litter size and -0.0356~0.0894 for birth weights. However, no significant differences were observed in general combining ability effects on litter size and birth weights. Specific combining ability effects estimated in line-crosses were -1.0388~1.7913 for litter size and -0.1144~0.1343 for birth weights. However, the specific combining ability effects for litter size and birth weights appeared to be insignificant. The reciprocal effects, which appeared to be significant, were -2.26 from BALB/c ${\times}$ C3H, 1.84 from CBA ${\times}$ C57BL and -1.50 from BALB/c ${\times}$ CBA for litter size. For birth weights, the reciprocal effects were estimated -0.26 from CBA ${\times}$ C57BL, 0.15 from BALB/c ${\times}$ CBA and -0.15 from BALB/c ${\times}$ C57BL.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.44 no.1
• /
• pp.24-28
• /
• 2015

The present study was carried out to investigate the in vivo single-dose acute toxicity of Bacillus subtilis JNS isolated from Cheonggukjang, which is a probiotic candidate showing strong and broad antibacterial activity. The test sample was orally administrated to male and female ICR mice at a highest dose of 2,000 mg/kg for 14 days. No significant change in general conditions, mortalities, body weight changes, clinical signs, autopsy findings, or presence of gross lesions was observed in either sex of mice. The results indicate that up to 2,000 mg/kg of B. subtilis JNS had no adverse effect on ICR mice.