• Clinical and Experimental Pediatrics
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• v.49 no.6
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• pp.610-616
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• 2006

Purpose : The purpose of this study was to evaluate the timing of sexual maturation and secular trends of menarchial age in Korean adolescents. Methods : Nine hundred eighty two school students and 119 university female students were included. Tanner's pubertal assessment method was applied using a self-assessment sheet with pictures for their developmental stages. A medical checkup database from 1,156,022 women was also used to analyze the age of menarche from the year 1900 to 1980. Results : Onset of puberty was at $11.3{\pm}1.3$ years(y) in girls and $12.1{\pm}1.5$ y in boys and total pubertal duration was 3.6 y in girls and 3.3 y in boys. Height at the onset of puberty was $146.1{\pm}7.9cm$ in girls and $152.7{\pm}9.8cm$ in boys. Weight at the onset of puberty was $39.3{\pm}6.9kg$ in girls and $47.7{\pm}14.4kg$ in boys. The mean age of menarche was $12.0{\pm}1.0y$ and mean age at nocturnal emission was $12.3{\pm}1.8y$. By age ten, 3.0 percent of girls experienced menarche, which increased to 41.1 percent by age 12, and 98.0 percent by age over 15. By SMR 2 breast stage, 18.2 percent of girls experienced menarche, which increased to 66.1 percent and 91.7 percent by SMR stages 3 and 4, respectively. By SMR 2 pubic hair stage, 52.0 percent and by SMR 3, 93.8 percent of girls experienced menarche. While the menarchial age of women born around 1980 was $12.4{\pm}1.1y$, the menarchial age of women born around 1990 was $12.0{\pm}1.1y$. Age at menarche has been advanced approximately by 2 years between 1900 and 1980 birth cohorts. Conclusion : There was a downward secular trend in pubertal timing. Age at menarche has been advanced by 2 years during the last 80 years. Further large scale, prospective studies, including inspection by specialists, are needed to provide reference data for pubertal timing in Korean adolescents.

• The Korean Journal of Zoology
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• v.15 no.1
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• pp.25-33
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• 1972

Two-Cell mouse embryos were incubated in the anterior chamber of the rat eye, which has been known as the best place among other animals' for the mouse ovum maturation, in order to observe the capability of their early development. Within 120 hours after incubation, 71.0% of two-cell embryos have developed to the blastocysts in the male rat eye, while only 38.5% in the eye of the same mouse as donated two-cell embryos. Thus, the rat eye chamber provides more favourable environment to the embryos than the mouse itself. The results are consistent with those of the previous studies comparing the maturation of the mouse follicular oocytes in the mouse and the rat eye chamber. Although the aqueous humor which is filled in the anterior chamber of the eye is characterized by its specific properties, being of higher osmolarity, higher concentrations of ascorbic acid, pyruvate and lactate, but lower of proteins and lower temperature than those in blood or lymph serum, The embryos are able to under-take their cleavage as normal as in vivo or in vitro. Concerning with a number of studies in vitro on the development of the mouse embryos which are requiring a very limited condition, the fact that they are able to manage their further development under very different enviroment from our knowledges would provide us a moment to understand their behavior during the early development. The difference of the proportion of the developed blastocysts between in the mouse eye chamber and in the rat can possibly be resulted from the species specific difference in the physicochemical properties between their eye chambers. This assumption is based upon the findings by many investigators who chmpared the nature of the eye chamber of various animals. As a consequence, the rat eye chamber might consist of better properties for the embryonal growth than the mouse eye chamber. The mouse embryos cleaved with a delayed period. In normal development they complete almost the cleavage within 94 hours after fertilization. However, in the present studies, 81.1% of two-cell embryos developed to the blastocysts and the morula in 120 hours in the eye chamber, assumed to be about 154 hours after fertilization. Such delay in development would be caused mainly by the low temperature of the eye chamber. At present we can make two assumptions to explain the capability of the emtryonal development in the eye chambers. One is that the embryos would possess an ability to adapt themselves to the environment which provides unfavourable conditions. The other is that the embryos might remain for a certain duration in the eye chamber, which is filled with a new body fluid produced immediately after the loss of the aqueous humor and the fluid of which becomes similar to blood serum in component. The first assumption is highly reliable since the embryonal cells are mostly at the undifferentiated state and so they probably engage a simple metabolism during their early period. The second assumption is induced by the fact that the rabbit eye chamber produces a plasmoid humor which has mostly similar components to blood serum after loss of aqueous humor through cornea by puncturing. However, the plasmoid humor is substituted by the initial aqueous humor in eight hours. Even though this finding, production of the new fluid, could be applied to the rat eye, it is hardly reliabel that the plasmoid humor remains for such a long period as 120 hours. Consequently, the development of the embryos is more likely due to their adaptability to the new environment during their early developmental stages.

• Research in Plant Disease
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• v.10 no.4
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• Clinical and Experimental Reproductive Medicine
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• v.38 no.4
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• pp.228-233
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• 2011

Objective: To investigate the effectiveness of GnRH antagonist multiple-dose protocol (MDP) with oral contraceptive pill (OCP) pretreatment in poor responders undergoing IVF/ICSI, compared with GnRH antagonist MDP without OCP pretreatment and GnRH agonist low-dose long protocol (LP). Methods: A total of 120 poor responders were randomized into three groups according to controlled ovarian stimulation (COS) options; GnRH antagonist MDP after OCP pretreatment (group 1), GnRH antagonist MDP without OCP pretreatment (group 2) or GnRH agonist luteal low-dose LP without OCP pretreatment (group 3). Patients allocated in group 1 were pretreated with OCP for 21days in the cycle preceding COS, and ovarian stimulation using recombinant human FSH (rhFSH) was started 5 days after discontinuation of OCP. Results: There were no differences in patients' characteristics among three groups. Total dose and days of rhFSH used for COS were significantly higher in group 3 than in group 1 or 2. The numbers of mature oocytes, fertilized oocytes and grade I, II embryos were significantly lower in group 2 than in group 1 or 3. There were no significant differences in the clinical pregnancy rate and implantation rate among three groups. Conclusion: GnRH antagonist MDP with OCP pretreatment is at least as effective as GnRH agonist low-dose LP in poor responders and can benefit the poor responders by reducing the amount and duration of FSH required for follicular maturation.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.389-398
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• 1999

Objective: This study was designed to evaluate the effects of endogenous LH surge, GnRH agonist (GnRH-a) or human chorionic gonadotropin (hCG) as ovulation trigger on pregnancy rate by intrauterine insemination (IUI). Method: Patients received daily 100 mg of clomiphene citrate (CC) for 5 days starting on the third day of the menstrual cycle followed by human menopausal gonadotropin (hMG) for ovulation induction. Follicles larger than >16 mm in diameter were present in the ovary, frequent LH tests in urine were introduced to detect an endogenous LH surge. Final follicular maturation and ovulation were induced by GnRH-a 0.1 mg (s.c.) or hCG $5,000{\sim}10,000$ IU (i.m.) administration except natural ovulation. Pregnancy was classified as clinical if a gestational sac or fetal cardiac activity was seen on ultrasound. Results: There were no differences in age, duration of infertility and follicle size, but more ampules of hMG were used in GnRH-a group compared to hCG 10,000 IU treated group (p<0.05). Lower level of estradiol ($E_2$) on the day of hCG or GnRH-a injection was observed in hCG 10,000 IU group than other treatment groups (p<0.01). The overall clinical pregnancy rate was 19.8% per cycle (32/162) and 22.2% per patient (32/144). Pregnancy rate was higher in natural-endogenous LH surge group (37.5%, 9/24) than GnRH-a (18.8%) or hCG treated group (20.9% & 13.9%), but this difference was not statistically significant. No patient developed ovarian hyperstimulation. Abortion rate was 22.2% (2/9) in hCG 5,000 IU group. Delivery or ongoing pregnancy rate was 37.5% (9/24), 18.8% (3/16), 16.3% (7/43) and 13.9% (11/79) in endogenous LH surge, GnRH-a, hCG 5,000 IU and hCG 10,000 IU treatment groups, respectively. Conclusion: These results support the concept that use of natural-endogenous LH surge in stimulated cycles may be more effective to obtain pregnancies by IUI than GnRH-a or hCG administration.

• Journal of Embryo Transfer
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• v.22 no.4
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• pp.245-249
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• 2007

The aim of present experiment was to examine hatching rate as in vitro indicator of viability of porcine embryos before early stage embryo transfer such as zygotes or 2-cell stage embryos. Cumulus-oocyte complexes (COCs) collected from ovaries were matured in North Carolina State University 23 (NCSU-23) containing 10% porcine follicular fluid (pFF), 10 ng/ml epidermal growth factor (EGF), $10{\mu}g/ml$ follicle stimulating hormone (FSH), $35{\mu}g/ml$ luteinizing hormone (LH), and 1mg/ml cysteine. After 24 hours, the COCs were transferred to the same medium without hormones. After 65h of maturation, oocytes were exposed to phosphate buffered saline (PBS) with 7% ethanol (v/v) for 7 minutes, and then the oocytes were washed and cultured in tissue culture medium (TCM) 199 containing 5 ug/ml cytochalasin B for 5h at $38.5^{\circ}C$ in an atmosphere of 5% $CO_2$ and 95% air with high humidity. After cytochalasin B treatment, the presumptive parthenotes were cultured in porcine zygote medium (PZM)-5 and cleavage of the parthenotes was assessed at 72h of activation, Normally cleaved parthenotes were cultured for an additional 8 days to evaluate their ability to develop to blastocyst and hatching stages. The fetal bovine serum (FBS) were added at Day 4 or 5 with concentrations of 2.5, 5 or 10%. The blastocyst rates were ranged within $39.1{\sim}70%$ in each treatment. However hatching rate was dramatically decreased in non-addition group. In this experiment, embryo viability in female reproductive tract may be estimated before embryo transfer with in vitro culture adding FBS by hatching ability.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.23 no.1
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• pp.27-36
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• 2017

In order to determine the relationship between water content and flower qualities of oriental hybrid lily cv. 'Siberia' cut flower, flowers were subjected to dry and cold storage at $5^{\circ}C$ for 3, 6, and 12 days and subsequently exposed to ambient temperature ($26^{\circ}C$) in bottles with water for up to 16 days. Flowers stored at $22^{\circ}C$ in dry condition for 3 days were used as the control. Changes in fresh weight, moisture content, water balance, flowering stages, osmolality and vase life of cut flowers were observed. Flowers treated with cold and dry storage had higher moisture content compared to control sample. However, this trend was evident only for 3-day cold and dry stored sample during the whole storage period. The fresh weight of cut flowers increased gradually when the samples were transferred to ambient temperature in water bottles and then declined steadily before reaching the peak in between 6-8 days of vase life. However, the changes of fresh weight of control sample were substantially faster than samples pre-treated with cold and dry storage. This was also correlated with the water balance of cut flower as it reached the minus (-) value in 6-8 days of vase life at ambient temperature. Cut lily flowers showed high osmolality values corresponding with the duration of dry storage regardless of low or higher temperature. However, osmolality had no effect on vase life since flower stem absorbed water rapidly at the end of dry storage period. Our vase life results suggest that cold and dry storage of lily cut flowers for a certain period could ensure longer vase life at ambient temperature. It was observed that prolonging the storage period at cold and dry condition for more than a week significantly increased bud abortion, reduced longevity of flowers and reduced the vase life of cut flowers. On the other hand, the shorter cold and dry storage treatment delayed the bud opening and senescence of the flowers, thus, slowering the normal maturation and aging. Results indicated that dry and cold storage at $5^{\circ}C$ for 3 days was effective in maintaining and preserving overall quality and vase life at ambient condition of oriental hybrid lily cut flowers.

• Clinical and Experimental Pediatrics
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• v.50 no.9
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• pp.912-918
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• 2007

Purpose : Breast milk contains several components that provide specific immunity and affect the maturation of the infant's immune system. Allergic disease (AD), including atopic eczema, asthma, allergic rhinitis, and food allergy is characterized by an imbalance between cytokines produced by distinct T-helper cell subtypes. The aim of the study was to investigate the concentrations of cytokines and chemokines that were involved in allergic reactions in breast milk from allergic and nonallergic mothers and then analyse the effect of breastfeeding duration on the prevalence of allergic disease in the age of two. Methods : The breast milk samples were collected from mothers with AD (n=88) and without AD (n=47). Breast milk was collected at the second day (colostrum) and four weeks later (mature milk).The level of Interlukine (IL)-4, IL-5, IL-6, IL-8, IL-10, IL-13, $TGF-{\beta}1$, $TGF-{\beta}2$, RANTES in breast milk were determined by commercially available enzyme-linked immunosorbent assay (ELISA) kits according to the manufacturer's instructions. Results : Mothers with AD had a higher concentration of IL-8 in colostrum compared with those without AD (P=0.021). But, $TGF-{\beta}1$ and $TGF-{\beta}2$ were higher concentrated in colostrum of mother without AD (P=0.013, P=0.001). Whereas concentrations of other cytokines were not significantly different between the two groups. There was no association between levels of cytokines and chemokines in the breast milk and allergic development during the first 2 years of life in the infants. Conclusion : The higher concentration of $TGF-{\beta}1$ and $TGF-{\beta}2$ in colostrum from non-allergic mothers may explain the protective effect. But, the higher concentrations of IL-8 in colostrum from allergic mothers may in part explain the controversial results on the protective effect of breastfeeding against allergic diseases. We conclude that there is no convincing evidence form a relation between cytokines in breast milk and allergic diseases in infants. Longer follow-up are necessary to evaluate the effects of breast milk components on AD.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.27-37
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• 1990

The extrafetal transfer of $Li^{+}$ in amniotic fluid was studied in 45 pregnant rabbits. LiCl solution was administered either intravenously to mother or directly into the amniotic sac and monitored the appearance and disappearance of $Li^{+}$ in the amniotic fluid, then calculated the transfer rate of $Li^{+}$ of extrafetal origin. To study the transplacental $Li^{+}$ transfer, a solution of 150 mM LiCl was infused continuously via maternal vein (initial dose: 0.7 mmol/kg, maintaining dose: 0.03 mmol/kg/min) and the $Li^{+}$ concentration was measured in maternal blood and amniotic fluid after 60 and 120 minutes of infusion. Change in the volume of aminotic fluid was determined by Congo red dilution method at the same time. Effects of duration of gestation was not considered in this study. Extrafetal transport of $Li^{+}$ into the amniotic fluid was estimated by comparing the $Li^{+}$ concentration and volume of amniotic fluid determined before and after ligating the placental vessels. Extrafetal $Li^{+}$ transport from the amniotic fluid was determined by observing the time dependent disappearance of $Li^{+}$ and Congo red in amniotic fluid after injecting 0.5 ml solution of 15 mM or 90 mM LiCl and 50 mg/ml Congo red. Following are the results obtained: 1) During infusion of LiCl through maternal vein the ratio of the aminotic $Li^{+}$/maternal plasma $Li^{+}$ increased significantly along with the increment of fetal weight. 2) The volume of amniotic fluid of larger fetuses than 20.5 gm increased significantly during administration of LiCl while that of smaller fetuses did not change. 3) After umbilical cord ligation the $Li^{+}$ concentration of amniotic fluid of larger fetuses than 20.5 gm was decreased to $59.9{\pm}10.3%$ and $56.9{\pm}42.9%$ $(mean{\pm}S.D.)$ of those of control group after 60 and 120 minutes of LiCl infusion respectively. In amniotic fluid of smaller fetuses than 20.5 gm, there was no significant difference between control and ligation groups. 4) The disappearance rate of Congo red in the amniotic fluid was $45.2{\pm}8.2%/hr$. 5) The disappearance rate of $Li^{+}$ after intraamniotic injection of LiCl depended on the amount injected. On injecting $7.5\;{\mu}mol$ LiCl, $Li^{+}$ disappeared rapidly from the amniotic fluid and the rates after 60 min and 90 min were $97.0{\pm}2.8,\;98.5{\pm}2.0%$ respectively. On injecting $45\;{\mu}mol$ LiCl, the rates were $56.0{\pm}15.4,\;78.9{\pm}14.5%$ at 60 and 90 min. 6) From the above results it was concluded: a) $Li^{+}$ transfer into the amniotic fluid increased along with the fetal growth and one half of $Li^{+}$ influx is through the extrafetal route even after the maturation of fetal kidney. b) One half of the $Li^{+}$ transfer from the amniotic fluid was through swallowing of fetus, while the remaining half was transfered rapidly through amniotic membrane, which was concentration limited.

• Journal of Sericultural and Entomological Science
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• v.15 no.2
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• pp.9-14
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• 1973

In order to find out effects of the generative power of silk worm moth which have been brought up in the high temperature accommodation at their pupa stage. For this specific study, 9 different kinds of male silk worms have been selected as specimen. All those specimen were brought up in the normal temperature at their larvae stage and after the pupation period they have been accommodated in the condition of high temperature for a certain length in accordance with the study programme. Afterwards, those mlae specimen were copulated with Suwon jam 103${\times}$104 which were all brought up in normal conditions. This study was carried out to find the copulation function as well as the ratio of unfertilized eggs(male sterility test). Results of study have been revealed as follows: 1) Although some differences were observed, male pura which have been brought up in the condition of high temperature shown the low rate of unfertilized eggs rather than those were brought up in the normal conpition. 2) In this group the eclosion(emergency) has been found to be poor rather, than those specimen brought up in normal conditions. 3) The copulation function of Moran, Daedong, J124 and C108 specimen were found to be poor than those of Suwon jam. 4) Fertility rate of Moran, Daedong, J124 and C108 was found to be around 65%. This figure is rather lower than what we normally expect. 5) Unfertilized egg ratio of Moran, Daedong and C108 were found to be around 20% if they were brought up in the condition of high temperature for one day from the time of pupation: 40% at 2 days, and 70% at 3 days duration. More than 3 days treatment has shown no progress in the unfertilized egg ratio. 6) One day's treatment for the pupa at the later stage has shown the unfertilized egg ratio of about 10%; 20% at 2 day's treatment, 35% at 3 day's treatment, 40-60% at 4 day's treatment, more than 60% at 5 day's treatment, and the 70% of fertilized egg ratio was only observed when the treatment days come to 7 days. It was understood that the unfertilized egg ratio was high at the antepupa stage rather than that of post-pupa stage. 7) According to the result of observation the sperm in copulatory pouch and seminal receptacle out of the normal female silk worm which have been copulated with the male brought up in the condition of high temperature at their moth stage. The reproduction system found in the control zone has been found to be normal and the sperm is amountful and active in motion while the sperm found in the treatment to be limited in amount and slow in motion. The observation was made within 5 hours from the copulation. 8) According to the result of observation of sperm of seminal receptacles of the female silkworm moth, and according to that observation of sperm in the seminal receptacle in female silkworm moth, the amount of sperm and mobility in the female moth brought up in high temperature were poor comparing that were brought up in normal temperature zone. Some of them are even found to be no trace of such. 9) Appearance and mosle of the copulatory organ of the male silkworm moth was found to be no anatomical change. 10) Testis of the later pupa stage which was brought up in the high temperature was found to be almost net developed to anucleate sperm and they are degenerated at stage of between maturation division and sperm abnormal stage. Mean time at control zone, the formation of anucleate sperm was already observed.