• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.858-864
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• 2015

Developmental changes in the vocal signals of serotine bats (Eptesicus serotinus) during their infancy were examined in this study. The analysis was conducted on 4 infant serotine bats from 1 to 40 days after their birth. Pulse duration (PD), pulse interval (PI), peak frequency (PF), maximum frequency ($F_{MAX}$), minimum frequency ($F_{MIN}$), and bandwidth (BW) were measured. As the bats grew, their vocalizations became increasingly consistent and similar to those of adults. For infant bats, PD and PI decreased as they grew older, whereas PF, $F_{MAX}$, $F_{MIN}$, and BW increased. The greatest change in vocalizations was observed between the $10^{th}$ and $20^{th}$ days after birth. Also, PF, $F_{MAX}$, $F_{MIN}$ and BW, which describe sound frequency, increased dramatically during the period between the $10^{th}$ and the $20^{th}$ days. In contrast, the greatest change in PD occurred between the $30^{th}$ and $40^{th}$ days after birth. The results collected in this study suggest that frequency increased as the contraction ability of the muscles developed by around 20 days of age. Muscle relaxation ability, which is related to PD, was found to develop significantly at 30 to 40 days of age. According to the results of this study, although 40 day-old infant bats are not yet able to fly, their vocal signals were similar to those of adults. This indicates that vocal development and flying activity develop separately in young bats.

• Development and Reproduction
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• v.4 no.1
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• pp.95-100
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• 2000

A large number of man-made chemicals that have been released into the environment have the potential to disrupt the endocrine system of animals and humans. There is a critical developmental period during which sexual brain differentiation proceeds irreversibly under the influence of gonadal hormone. Recently we identified KAP3 gene expressed during the critical period of rat brain sexual differentiation. KAP3 functions as a microtubule-based motor that transports membranous organelles anterogradely in cells, including neurons. In the present study, we aimed to investigate the effect of endocrine disrupter, Dichlorodiphenyl trichloroethane (DDT), on the KAP3 gene expression during critical period of rat brain development. Maternal exposure to DDT increased the level of KAP3 mRNA in male and female fetus brains when examined on the gestational day 17 (GDl7). In postnatal day 6, DDT suppressed the expression of KAP3 gene in male and female rat brain. Also, the body weight and fertilization rate were decreased in the DDT exposured rats. These results showed that endocrine disrupter, DDT, can affect the transcriptional level of brain sexual differentiation related gene, KAP3, in the prenatal and the neonatal rat brain and that maternal exposure to endocrine disruptors may lead to a toxic response in embryonic differentiation of brain. And so KAP3 gene may be used a gene maker to analyse the molecular mechanism for toxic response in animal nerve tissues exposed to endocrine disruptors.

• Journal of Nutrition and Health
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• v.2 no.4
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• pp.113-125
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• 1969

These experiments were designed to study the influence of early protein undernutrition on growth, behaviors toward food, general attitude toward a new environment, brain size and body composition of the experimental rats. The following experimental groups were studied. Lactation period (3 weeks) (Diets of mother rats) 25% Casein diet 12% Casein diet 25% Casein diet 25% Casein diet 12% Casein diet 12% Casein diet After-weaning protein deprivation period None deprivation (25% Casein diet) None deprivation (25% Casein diet) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) After a long period of rehabilitation with 25% casein diet the following results were obtained. 1. Growth rate during lactation period is closely related with the protein levels of the diet for mother rats. The average body weight of offsprings of the mother rat fed 25% casein diet is 46.0 grams at 21 days old. However, that of the mother rat fed 12% casein diet is only 25.0 grams. 2. The group of protein undernutrition during lactation (S weeks) (offsprings of mother rat fed low protein diet, 12% casein diet) could never catch up with the normal group in its growth even after twenty-four (24) weeks of rehabilitation. 3. However, the groups of protein undernutrition during either four (4) or even eight (8) weeks after weaning could catch up with the normal group in their growth after long period of rehabilitation. 4. The absolute amounts of carcass protein and fat of the normal group are larger than those of the protein deficient groups. In terms of percent carcass, however, the normal group showed higher body fat and lower body protein than the early deficient groups. However, there is no difference between preweaning (3 weeks) and postweaning (8 weeks) deficient groups. It is assumed, from these differences in body composition, that there might be any differences in physiological and metabolic functions among these various groups, and also that the basic formation of various metabolic regulators (protein-nature) might be fixed mostly during lactation and postweaning period. 5. The groups of protein undernutrition during either three (3) weeks lactation or four (4) weeks after weaning are not so remarkably different from the normal group in their amounts of food intake and spillage. However, the groups of undernutrition during either eight (8) weeks postweaning or eleven (11) weeks (3 weeks lactation period plus 8 weeks postweaning period) showed higher amounts of food intake and spillage. In these respects, it seems that desire for food is closely related with the degree of early hunger in protein and also seems that the longer be deficient in early life the more food spillage is found. 6. Both preweaning and postweaning deficient groups showed generally nervous and restless. The normal group is staid and showed less mobilities. 7. The average size of the brains of the group subjected to protein deficiency during three (3) weeks lactation period is smaller than that of the group of the eight (8) weeks postweaning deficiency. This means that the development of the brain is made mostly during lactation period. The group of the eleven (11) weeks postnatal deficiency is significantly different from the normal group in its brain development. It is assumed, in connection with the results of various maze tests reported, that the brain size is closely related with the intellectual ability.

• Toxicological Research
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• v.34 no.2
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• pp.173-182
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• 2018

Valproic acid (VPA) plays a role in histone modifications that eventually inhibit the activity of histone deacetylase (HDAC), and will affect the expressions of genes Pdx1, Nkx6.1, and Ngn3 during pancreatic organogenesis. This experiment was designed to study the effect of VPA exposure in pregnant rats on the activity of HDAC that controls the expression of genes regulating the development of beta cells in the pancreas to synthesize and secrete insulin. This study used 30 pregnant Sprague-Dawley rats, divided into 4 groups, as follows: (1) a control group of pregnant rats without VPA administration, (2) pregnant rats administered with 250 mg VPA on day 10 of pregnancy, (3) pregnant rats administered with 250 mg VPA on day 13 of pregnancy, and (4) pregnant rats administered with 250 mg VPA on day 16 of pregnancy. Eighty-four newborn rats born to control rats and rats administered with VPA on days 10, 13, and 16 of pregnancy were used to measure serum glucose, insulin, DNA, RNA, and ratio of RNA/DNA concentrations in the pancreas and to observe the microscopical condition of the pancreas at the ages of 4 to 32 weeks postpartum with 4-week intervals. The results showed that at the age of 32 weeks, the offspring of pregnant rats administered with 250 mg VPA on days 10, 13, and 16 of pregnancy had higher serum glucose concentrations and lower serum insulin concentrations, followed by decreased concentrations of RNA, and the ratio of RNA/DNA in the pancreas. Microscopical observations showed that the pancreas of the rats born to pregnant rats administered with VPA during pregnancy had low immunoreaction to insulin. The exposure of pregnant rats to VPA during pregnancy disturbs organogenesis of the pancreas of the embryos that eventually disturb the insulin production in the beta cells indicated by the decreased insulin secretion during postnatal life.

• Development and Reproduction
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• v.8 no.1
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• pp.27-33
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• 2004

To investigate the mechanism of germ cell death in postnatal stage of mouse, the involvement of apoptotic executioners, caspase-3 and caspase-activated DNase(CAD), and apoptotic initiators, Bax Fas and Fas ligand, in the germ cell death has been studied. Immune-labels of active caspase-3 and CAD were located in TUNEL-positive, apoptotic, oocytes as well as normal oocytes of primary or secondary follicles. CAD immune-labels were also detected in the nucleus of TUNEL-positive oocytes. Most of oocytes showing positive immune-labeling of active caspase-3 or CAD had vacuoles in their cytoplasm, which is the morphological characteristic of oocyte during folliclar atresia. Bax immune-stains were detected in the atretic oocytes which showed the vacuole in their cytoplasm. Positive immune-labels for Fas ligand was localized in TUNEL-positive or atretic oocytes. Presence of immunoreactivity of active caspase-3 and CAD in TUNEL-positive germ cells implicate that active raspase-3 and CAD might play a role in germ cell apoptosis during early development of mouse ovarian follicle. Immunohistochemical localization of Bax and Fas ligand in TUNEL-positive oocytes suggests that these might be the most plausible modulator of oocyte apoptosis.

• Development and Reproduction
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• v.16 no.2
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• pp.95-100
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• 2012

Bisphenol A (BPA), a chemical with weak estrogenic activity is reported to affect preimplantation embryos, fetuses and alter their postnatal development. This study amied to determine the relation between the levels of BPA in the amniotic fluid and pregnancy outcomes. ELISA was used to measure amniotic fluid BPA in 120 pregnant women who underwent genetic amniocentesis at 15~20 weeks gestation. The most common indication for amniocentesis was advanced maternal age (35 yrs or older). BPA was detected in all amniotic fluid. The range of amniotic fluid BPA concentrations was from 0.89 ng/mL to 37.13 ng/mL with a mean level of 7.24 ng/mL. We compared the means of amniotic fluid BPA concentrations according to maternal age (${\geq}35$ vs. <35 yrs), fetal sex (male vs. female), gestational age at birth (${\geq}37$ vs. <37 weeks), and infant birth weight (${\geq}2.5$ vs. <2.5 kg). No significant differences were found in these outcomes. This is the first report of amniotic fluid BPA levels in Korean pregnant women. Our findings suggest that BPA may not affect the pregnancy outcomes such as fetal sex, preterm delivery and low birth weight. Whether prenatal exposure to BPA can have teratogenic effect on developing embryo needs to be studied.

• Journal of Korean Medical classics
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• v.4
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• pp.75-100
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• 1990

As a result, the investigation into Gyung-Ak (景岳)'s theory of Myungmun (命門) was led to the next conclusions. First, Gyung-Ak (景岳) defmed Myungmun as the gate of Suncheon (先天) and Whoocheon (後天), by which the life of Suncheon is obtained and the life of Whoocheon is maintained. He maintained that Myungmun is located between two kindneys, not sided to the right as in the Nankyeong (難經), and considered the substance of Myungmun as Jagung (子宮 ${\fallingdotseq}$ uterus) or the other names as such Jaho (子戶), Jajang (子腸) Danjeon (丹田), Hyeolsil (血室), etc. On the essence or function of Myungmun it was considered as Taegeuk (太極) of the body which shapes the North Pole in the center of the body, and as the hinge of rise and fall, as controller of Soowha-action (水火作用) and Eumyang-changing (陰陽變化), and as storage of Suncheon Jinil-ki (先天 眞一之氣), the source of life and vitality and as the spring of Twelve-Jang (十二藏). Thus, the function of Five-Jang (五臟 ${\fallingdotseq}$ Five-Viscera) and Six-Boo (六腑 ${\fallingdotseq}$ Six-Bowels) and actions of life is obtainded by Myungmun, and the life and death of man and the change of life is related to that. Bi-Wi (脾胃 ${\fallingdotseq}$ Spleen & Stomach) as well as Myungmun is the root of Five-Jang and Six-Boo, but since Bi-Wi is the base of postnatal nutrition to belong to the son of Wonyang (元陽), Myungmun is treated more important as the mother of Bi-Wi. Sin (賢 ${fallingdotseq}$ Kidney) was perceived as inseparably related with Myungmun, but in the course of theoretical development the function of Sin was considered to be ultimately operated by the action of Myungmun. In the Theory of Jineum (眞陰論), Gyung-Ak full accounted the diverse nature of disease and patholog from Soowha-shortage of Myungmun, and presented the laws and methods of medical treatment to those. Finally, in his theory related to Myungmun, some logical contradiction and confusion in conceptions was discovered and the anatomy of Present age proved that the location of Jagung and DanJeon, which he recognized as the substance of Myungmun is not coincided. Summerizingly, the Gyung-Ak's theory of Myungmun closely related the theory of Myungmun to the theory of Eumyang-Jungki (陰陽精氣論), by whole discourse of the characteristics of physiology possessing Soowha of Myungmun on the foundation of Eumyang-hogeun (陰陽互根) and Jungki-hosaeng (精氣互生). Gyung-Ak regarded the function of Myungmun as more important than any other Jang, discoursed more systematically and more specifically about the Myungmun than any others, and presented the theory of Sin-Myung (賢命理論) and prescription which is important to Care of Health and Medical Treatment (養生治病), thus influenced very greatly on the development of Oriental Medicine.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.439-445
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• 2018

T-type calcium channels are low voltage-activated calcium channels that evoke small and transient calcium currents. Recently, T-type calcium channels have been implicated in neurodevelopmental disorders such as autism spectrum disorder and neural tube defects. However, their function during embryonic development is largely unknown. Here, we investigated the function and expression of T-type calcium channels in embryonic neural progenitor cells (NPCs). First, we compared the expression of T-type calcium channel subtypes (CaV3.1, 3.2, and 3.3) in NPCs and differentiated neural cells (neurons and astrocytes). We detected all subtypes in neurons but not in astrocytes. In NPCs, CaV3.1 was the dominant subtype, whereas CaV3.2 was weakly expressed, and CaV3.3 was not detected. Next, we determined CaV3.1 expression levels in the cortex during early brain development. Expression levels of CaV3.1 in the embryonic period were transiently decreased during the perinatal period and increased at postnatal day 11. We then pharmacologically blocked T-type calcium channels to determine the effects in neuronal cells. The blockade of T-type calcium channels reduced cell viability, and induced apoptotic cell death in NPCs but not in differentiated astrocytes. Furthermore, blocking T-type calcium channels rapidly reduced AKT-phosphorylation (Ser473) and $GSK3{\beta}$-phosphorylation (Ser9). Our results suggest that T-type calcium channels play essential roles in maintaining NPC viability, and T-type calcium channel blockers are toxic to embryonic neural cells, and may potentially be responsible for neurodevelopmental disorders.

• International Journal of Oral Biology
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• v.35 no.4
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• pp.169-175
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• 2010

Cholinesterase (ChE) is one of the most ubiquitous enzymes and in addition to its well characterized catalytic function, the morphogenetic involvement of ChE has also been demonstrated in neuronal tissues and in non-neuronal tissues such as bone and cartilage. We have previously reported that during mouse tooth development, acetylcholinesterase (AChE) activity is dynamically localized in the dental epithelium and its derivatives whereas butyrylcholinesterase (BuChE) activity is localized in the dental follicles. To test the functional conservation of ChE in tooth morphogenesis among different species, we performed cholinesterase histochemistry following the use of specific inhibitors of developing molar and incisors in the hamster from embryonic day 11 (E11) to postnatal day 1 (P1). In the developing molar in hamster, the localization of ChE activity was found to be very similar to that of the mouse. At the bud stage, no ChE activity was found in the tooth buds, but was first detectable in the dental epithelium and dental follicles at the cap and bell stages. AChE activity was found to be principally localized in the dental epithelium whereas BuChE activity was observed in the dental follicle. In contrast to the ChE activity in the molars, BuChE activity was specifically observed in the secretory ameloblasts of the incisors, whilst no AChE activity was found in the dental epithelium of incisors. The subtype and localization of ChE activity in the dental epithelium of the incisor thus differed from those of the molar in hamster. In addition, these patterns also differed from the ChE activity in the mouse incisor. These results strongly suggest that ChE may play roles in the differentiation of the dental epithelium and dental follicle in hamster, and that morphogenetic subtypes of ChE may be variable among species and tooth types.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.3
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• pp.269-277
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• 2005

Objectives: Previously, we sought to compile a list of genes expressed during early folliculogenesis by using cDNA microarray to investigate follicular gene expression and changes during primordialprimary follicle transition and development of secondary follicles (Yoon et al., 2005). Among those genes, a group of genes related to the cell size growth was characterized during the ovarian development in the present study. Methods: We determined ovarian expression pattern of six genes related to the cell size growth (cyr61, emp1, fhl1, socs2, wig1 and wisp1) and extended into CCN family (${\underline{c}}onnective$ tissue growth factor/${\underline{c}}ysteine$-rich 61/${\underline{n}}ephroblastoma$-overexpressed), ctgf, nov, wisp2, wisp3, including cyr61 and wisp1 genes. Expression of mRNA and protein according to the ovarian developmental stage was evaluated by in situ hybridization, and/or semiquantitative reverse transcriptase polymerase chain reaction (RT-PCR), and immunohistochemistry, respectively. Results: Among 6 genes related to the cell size growth, cyr61 and wisp1 mRNA was detected only in oocytes in the postnatal day5 mouse ovaries. cyr61 mRNA expression was limited to the nucleolus of oocytes, while wisp1 was expressed in the cytoplasm and nucleolus of oocytes, except nucleus. cyr61 mRNA expression, however, was found in granulosa cells from secondary follicles. The rest 4 genes in the cell size growth group were detected in oocytes, granulosa and theca cells. Cyr61 and Wisp1 proteins were expressed in the oocyte cytoplasm from primordial follicle stage. Especially, Cyr61 protein was detected in pre-granulosa cells, Wisp1 protein was not. By using RT-PCR, we evaluated and decided that Cyr61 protein is produced by their own mRNA in pre-granulosa cells that was not detected by in situ hybridization. cyr61 and wisp1 genes are happen to be the CCN family members. The other members of CCN family were also studied, but their expression was detected in oocytes, granulose and theca cells. Conclusions: We firstly characterized the ovarian expression of genes related to the cell size growth and CCN family according to the early folliculogenesis. Cyr61 protein expression in the pre-granulosa cells is profound in meaning. Further functional analysis for cyr61 in early folliculogenesis is under investigation.