• Journal of Embryo Transfer
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• v.21 no.3
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• pp.255-262
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• 2006

The purpose of this study is to investigate the effects of vitrification in open pulled straws (OPS) methods on in vitro survival ability of porcine embryos. For in vitro maturation of immature oocytes, the porcine ovaries were collected from local slaughter-house. The cumulus-oocytes complexes were aspirated from 2 to 6 mm follicles. The collected oocytes were cultured for in vitro maturation in NCSU-23 medium with 5 mM hypotaurine, 0.57 mM cysteine, 10% porcine follicle fluid, 10 IU/ml PMSG and 10 IU/ml hCG for $21{\sim}22$ hrs. Then, the oocytes were more cultured $21{\sim}22$ hrs in vitro maturation in medium removed hormones. The frozen-thawed spermatozoa were washed by centrifugation 2 times for 10 min at 1,500 rpm in D-PBS with 5.56 mM glucose, 0.33 mM Na-pyruvate, 100 IU/ml penicillin, $100 {\mu}g/ml$ streptomycin and 4 mg/ml BSA. The fertilization medium used mTBM with 2 mM caffeine and 2 mg/ml BSA and adjusted to a pH of 7.2 to 7.4. The final concentration of spermatozoa was adjusted to $2.5{\times}10^6$cells/ml motile sperm during fertilization in vitro. At 8 hrs after insemination, the oocytes were transferred into NCSU-23 medium with 5.0 mM hypotaurine, 4 mg/ml BSA and 10 ng/ml EGF and cultured for 7 days. When the blastocysts of different stages were frozen-thawed by OPS methods, the proportions of embryos with normal morphology were significantly (p<0.05) higher in embryos frozen-thawed at expanded blastocyst stage (38.9%) than in early blastocyst stage (28.3%). On the other hand, the proportions of embryos damaged after frozen-thawing were significantly (p<0.05) higher in embryos frozen at early blastocyst stages than in expanded blastocyst stage. In another experiment, the normal embryos morphology after frozen- thawing were further cultured for 48 hrs. After culture, the proportions of embryos hatched were 6.7, 20.0 and 33.3% for embryos frozen-thawed at early blastocyst, mid-blastocyst and expanded blastocyst stages. These finding indicate the possible broader application for OPS methods, as frozen-thawed embryos may be accompanied by developmental stage according to requirements of the survival ability after freezing of blastocyst stage in the pig.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.628-635
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• 2014

The large amount of $CO_2$ emitted from mushrooms during incubation and developmental stages can be utilized in plant production systems as a $CO_2$ source. The objectives of this study were to measure the $CO_2$ emission and absorption rates of mushroom and lettuce, respectively, and to analyze the $CO_2$ concentrations at various ratios of mushroom and lettuce in a closed production system. The $CO_2$ emission rate of king oyster mushrooms (Pleurotus eryngii ( DC.) Qu$\acute{e}$l) and $CO_2$ absorption rate of lettuces (Lactuca sativa L. cv. Asia Heuk Romaine) were measured by using two closed acryl chambers ($1.0m{\times}0.8m{\times}0.5m$) in which indoor temperatures were maintained at $18^{\circ}C$ and $22^{\circ}C$, respectively. The lettuce was grown at a light intensity of PPF $340mol{\cdot}m^{-2}{\cdot}s^{-1}$ and with nutrient solution at EC $1.2dS{\cdot}m^{-1}$. The air was periodically circulated between the two chambers using a diaphragm pump. The $CO_2$ emission rate of the mushroom increased until the $15^{th}$ day after scratching (DAS) and then decreased. The rate also increased with increased indoor temperature. In particular, the $CO_2$ emission rate per fresh weight of fruit body increased by about 3.1 times after thinning compared to before thinning. In terms of $CO_2$ balance, the $CO_2$ emission rates from a bottle (950 mL) of the mushroom at 9, 12, and 14 DAS were equivalent to those of 3, 4.5, and 5.5 lettuce plants at 7, 10, and 12 DAT (days after transplanting), respectively. This work shows that balance in $CO_2$ concentration could be achieved using an appropriate ratio of the two crops in a closed production system.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.303-310
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• 1996

The objective of this study was to examine the effect of embryos development following IVF of in vitro-matured porcine oocytes treated with epidermal growth factor (EGF). When cumulus-enclosed oocytes were incubated in TCM 199 medium supplemented with (1) control group, (2) 10 ng/ml EGF, (3) 10${\mu}g$ml FSH and 10% FBS, or (4) 10 ng/ml EGF, 10 ${\mu}g$/ml FSH, and 10% FBS for 42 hr, the late developmental rates on NCSU (0.4% BSA) medium after fertilization were higher in (3) and (4) groups (13.4, 18.3%) than in (2) group (5.2%, p < 0.005), but (2) group is significantly higher than the development to blastocyst of oocytes of (1) group (1.2%). Also, when the cell number of total, ICM, and TE of those blastocysts at 6 day produced in vitro was investigated by double staining (PI and bisbenzimide), total cell number of (4) group (58.80${\pm}$ 11.90) was higher than that of (2) and (3) groups (42.17${\pm}$9.97, 49.07${\pm}$9.77, P < 0.05). ICM cell number of blastocysts of (4) group (11.69${\pm}$5.56) was higher than that of (2) and (3) groups (5.00${\pm}$4.24, 6.77${\pm}$4. 92, P < 0.05). Furthermore, the proportion of ICM in (4) group (19.0${\pm}$1.6) was higher than that in (2) and (3) groups (11.1${\pm}$3.0, 12. 7${\pm}$2.1). These results suggested that in vitromatured porcine oocytes treated with EGF alone can be developed to blastocyst, but high proportion on the development to blastocyst and number of total cell and ICM in blastocyst can be obtained when supplemented with additional FSH and FBS.

• Clinical and Experimental Reproductive Medicine
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• v.23 no.3
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• pp.319-326
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• 1996

The objective of this study was to investigate correlation between the morphology by microscopic assessments of surplus blastocysts produced in human IVF program and their cell number obtained by differential labelling method. For these experiments, 76 surplus human blastocysts were obtained from 36 patients on day 5 after IVF, the embryos were classified to early (ErB), early expanding (EEB), middle expanding (MEB), expanded blastocyst (EdB) according to their blastocoel expansion and zona thickness. When the ovum size and zona thickness of the classified blastocysts were measured using micrometer, although the embryos were produced in the same culture condition, there were significant variances in ovum size ($148.8 217.6{\mu}m$) and zona thickness ($1.2-14.4{\mu}m$). Total blastomere cell number counted after hoechst staining was increased by two to three fold during the transition period from ErB ($39.1{\pm}3.6$) to EdB ($(89.6{\pm}3.3)$) stage on day 5 after IVF. ICM ($11.9{\pm}1.8-22.2{\pm}4.3$) and TE ($24.5{\pm}3.6-70.0{\pm}7.7$) cell numbers using differential labelling were also showed the increased pattern according to the developmental level. Especially, EdB which showed poor ICM morphologically also indicated the low ICM cell number after differential labelling. This demonstrated that there is good correlation between the morphological assessment and the cell number. The count of ICM and TE nuclei using differential labelling can be used as an important criterion, if it is accompanied with morphological assessments, in selecting the better embryos for improving the pregnancy rates in human blastocyst transfer program.

• Journal of Plant Biology
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• v.38 no.1
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• pp.47-54
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• 1995

The present study performed the isolation of cytosolic ascorbate peroxidase (APX) isozymes and analyzed the pattern of their activity development and also investigated the change in some other enzyme activities related to the ascorbate-glutathione pathway from the senescing wheat leaves. The aim of this work is to examine the possibility that in the cytoplasm of wheat leaves the ascorbate-glutathione pathway p!ays a significant role in relation to leaf senescence involving an $H_2O_2$ accumulation and then to show the effect of benzyladenine (BA) on that pathway. During the leaf senescence characterized by increases in ChI breakdown and H202 accumulation under the 4-day dark incubation of matured leaf segments; i) no significant increase of total cytosolic APX was observed, ii) a dehydroascorbate reductase (DHAR) activity was decreased rapidly, iii) a slight increase of glutathione reductase (GR) activity occurred. In the BA-treated leaves; however, i) the total activity of APX increased conspicuously, ii) the decrease of DHAR activity was relatively inhibited, iii) the GR activity increase was more enhanced, and iv) the decrease of ascorbate content and the increase of H202 content were retarded as compared with those of control leaves. Three isozymes of cytosolic APX were found by using a native-electrophoretic gel in senescing wheat leaves and two of them occurred with major activity. In the developmental patterns of cytosolic APX isozymes, only two isozyme bands ("a" and "b") appeared with almost constant activity through 4 days of incubation in the control leaves, while one additional weak isozyme band ("c") and a little increase of "b" isozyme activity were detected in the BA-treated leaves. EspeciaUy, the development of "a" isozyme activity increased remarkably compared with that of control leaves. The increased capacity for peroxide scavenging due to the enhanced activity of all 3 enzymes (APX, DHAR, GR) participating in the ascorbate-glutathione pathway in BA-treated leaves suggested that this pathway might playa significant role in the processes related to the wheat leaf senescence.scence.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.308-317
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• 2015

This study attempted to identify the possibility of natural herbal extracts as an alternative, preventive agent of caries by comparing antimicrobial activities between natural herbal extracts and mouth rinsing solutions against Streptococcus mutans. Natural herbal plants were extracted with distilled water and ethanol, respectively, to measure the minimum growth inhibitory concentration of S. mutans depending on concentration, and among which, solvents showing high antimicrobial activity were selected to compare their antibiotic effects with those of mouth rinsing solutions. Also, to determine the concentration of natural medicinal herbs that can be used safely in the oral cavity, the extracts were treated to the normal gingival fibroblast cells depending on concentration in order to determine its cytotoxicity using MTT. In terms of the minimum growth inhibition concentration, the growth inhibition of S. mutans was more excellent in the ethanol extract than in the distilled water. When the minimum growth inhibition concentration was compared, Psoralea corylifolia of natural herbal ethanol extracts, and Hexamedine (Bukwang Pharm., Korea) of mouth rinsing solutions inhibited growth of S. mutans at the lowest concentration. When the minimum bactericidal concentration was compared, P. corylifolia of natural herbal extracts, and Hexamedine and Garglin (Dong-A Pharm., Korea) of mouth rinsing solutions eliminated S. mutans at a low concentration. The human gingival fibroblast was treated with natural herbal ethanol extracts at the minimum growth inhibition concentration of 10, 39, and $78{\mu}g/ml$. As the result, no cytotoxicity was found. When this was treated at different minimum bactericidal concentrations, natural herbal ethanol extracts showed cytotoxicity except P. corylifolia.

• Korean Journal of Veterinary Research
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• v.45 no.3
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• pp.325-334
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• 2005

Changes in the rabbit Leydig cell from birth to adulthood were studied in New Zealand white rabbits of 1, 7, 21, 35, 49, 70, 105, 147, 196, and 252 days (n = 8 rabbits per group) of age. The objectives of this study were to understand the fate of the fetal Leydig cells, to determine the changes in serum testosterone levels, and leutenizing hormone-stimulated testosterone production per testis in vitro, and to quantify adult Leydig cells by number and average volume with age. Testes of rabbits were fixed by whole body perfusion using a fixative containing 2.5% glutaraldehyde in cacodylate buffer, processed and embedded in Epon-araldite. Using $1{\mu}m$ sections stained with methylene blue-azure II, qualitative and quantitative (stereological) morphological studies were performed. Testosterone levels in the incubation medium of luteinizing hormone-stimulated (100 ng/ml) testosterone secretion per testis in vitro, and in serum were determined by radioimmunoassay. The average volume of a testis of 1-day-old rabbits was determined as $0.0073cm^3$ and the parameter increased linearly from birth to 252 days ($3.93cm^3$). The volume density of the seminiferous tubules increased with age from 33.76% at day 1 to 88.2% at day 252. The volume density of the interstitium represents 66.24% of the testicular parenchyma at day 1. This proportion progressively diminished during development to reach a value of 11.8% at day 252. The volume density of Leydig cells increased almost linearly from birth (0.001%) to 252 days (2.62%). Leydig cell mass per testis increases from 0.0012 mg to 0.25 mg between days 1 and 35, from 2.66 mg to 44.3 mg between days 49 and 105 and from 65.42 mg and 102.9 mg between days 147 and 252. The absolute numbers of adult Leydig cells per testis increased linearly from birth to 252 days. The average volume of adult Leydig cell on days 1, 7, 21 and 35 was not significantly different; a gradual and continued increase was observed thereafter, reaching a 3-fold increase at 196 and 252 days. Serum testosterone concentrations were not significantly different at day 1 compared days 7, 21, 35. Significant increases were observed at days 49 and 70. Values at days 70 and 105 and days 147, 196, and 252 were not significantly different. LH-stimulated testosterone production per testis in vitro was significantly different at day 1 compared days 7, 21, 35. Significant increases were observed at days 49 and 70. Hormonal values at days 105, 147, 196, and 252 were not significantly different. These data suggested Leydig cell developmental phase can be classified: a neonatal phase (1-7 days), a prepubertal phase (14-49 days) and an adult phase (70-252 days). Immature and mature adult Leydig cells, initially detected at days 7 and 49, respectively, and mature adult Leydig cells were abundant Leydig cell type according to the number and absolute volume per testis form day 49 onwards.

• Clinical and Experimental Pediatrics
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• v.53 no.3
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• pp.307-313
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• 2010

Purpose : Results of the Korea National Health Screening Program for Infants and Children, which was launched in November 2007, were evaluated for future research and policy development. Methods : Data from a total of 2,729,340 cases were analyzed. Five visiting ages, such as 4, 9, 18, 30, and 60 months, were included. Several parameters such as stunting, obesity, and positive rate of developmental screening were also analyzed. Telephone survey was performed in 1,035 users. For the provider survey, 262 doctors participated in our study. Results : The overall participation rate of users was 35.3%. This participation rate showed a decrement tendency to old age and low income. Only 6.9% of users participated in oral screening. Health screening was performed mainly in private clinics (82.6%). The recall rate of 4 months program users at the age of 9 months was 57.3%. The positive rate of screening was 3.1%, and was higher in the low-income group. By telephone survey, users reported that questionnaires were not difficult (94%) and overall satisfaction was good (73%). Longer duration of counseling was related with more satisfied users. Counseling and health education were helpful to users (73.2%). Doctors agreed that this program was helpful to children (98.5%). Conclusion : Korea National Health Screening Program for Infants and Children was launched successfully. Participation rate should be improved, and a quality control program needs to be developed. More intensive support following this program for children of low-income families may lead to effective interventions in controlling health inequality. Periodic update of guidelines is also needed.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.153-163
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• 2020

This study was conducted to evaluate the fitness of Tetranychus kanzawai Kishida on different host plants: young and old leaves of the mandarin orange 'shiranuhi' ((Citrus unshiu × C. sinensis) × C. reticulata), Japanese violet (Viola japonica Langsd.) and kidney bean (Phaseolus vulgaris L.). The development and oviposition experiments were conducted at constant temperatures (20, 25 and 30℃) and a life table parameters were estimated. T. kanzawai could complete it's development on 'shiranuhi' young leaves, japanese violet and kidney bean, while all died during the immature period on 'shiranuhi' old leaves. The total developmental period of T. kanzawai feeding on 'shiranuhi' young leaves was 17.4, 13.4 and 10.2 days at each temperature, respectively, which was longer than 16.1, 9.5 and 7.0 days of kidney bean. The female longevity of T. kanzawai on young leaves of 'shiranuhi' were 19.1, 15.0 and 12.3 days at each temperature, respectively, and there was no significant difference from 22.1, 14.1 and 10.9 days investigated from kidney bean. The fecundity was 18.1, 23.9 and 17.8 eggs per female, which was less than them of japanese violet and kidney bean at each temperature, respectively. As a result of estimating the life table parameters based on the experimental data, intrinsic rate of increase (r_m) were significantly different from each other, and appeared in the following order: kidney (0.1542, 0.2563 and 0.3251), japanese violet (0.1087, 0.2007 and 0.2673) and 'shiranuhi' young leaves (0.0868, 0.1002 and 0.1217) at each temperature, respectively. Finally, the management strategy against T. kanzawai in citrus orchards was discussed based on the results.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.325-330
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• 2005

This study was conducted to determine the effect of temperatures on the egg and nymphal development, adult longevity and oviposition of bean bug, Riptortus clavatus Thunberg, using Saealkong seed as food sources in fibrous nylon-tube at four different temperatures (20, 24, 28 and $32^{\circ}C$). Hatchability showed the highest value of 100% at $28^{\circ}C$ and decreased with increasing temperature. Egg duration ranged from 7 days at $32^{\circ}$ to 16.7 days at $20^{\circ}C$. Instar duration was longer with increasing instar stage. Nymphal duration was 38 days at $20^{\circ}C$, 30 days at $24^{\circ}C$, 23 days at $28^{\circ}C$, and 18 days at $32^{\circ}C$ Emergence rates to adult were 16, 41, 72 and 68% at 20, 24, 28 and $32^{\circ}C$, respectively. Female adult longelity ranged from a minimum 20 days at $20^{\circ}C$ to a maximum 63 days at $28^{\circ}C$, while the longevity of male ranged from 19 days at $20^{\circ}C$ to 60 days at $28^{\circ}C$. Preoviposition duration was shorter with increasing temperature and ranged from 11 days at $20^{\circ}C$ to 5 days at $32^{\circ}C$. Total number of eggs laid per female ranged from a minimum 21 eggs at $20^{\circ}C$ to a maximum 67 eggs at $28^{\circ}C$. Consequently, the estimated lower threshold tempeatures of each developmental stage were $10.3^{\circ}C$ for egg, and 9.3, 12.7, 10.0, 11.0 and 8.7 for the 1st, 2nd, 3rd, 4th and 5th instar, respectively.