• Applied Microscopy
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• 제47권4호
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• pp.242-250
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• 2017

The purpose of this study was to characterize the prenatal and postnatal development of the mouse parotid salivary gland and tooth, and to investigate the relationship between the developmental timing of the two organs. Development of parotid salivary gland begins on embryonic day 15 (E15), which is the prebud stage; E17 is the initial bud stage; E21 to postnatal day 3 (PN3) is the pseudoglandular stage; PN5 to PN10 is the canalicular stage; and PN21 is the terminal bud stage. At E15, the developing maxillary molar tissue is at the bud stage; at E17, it is at the cap stage; at E21, it is at the early bell stage; PN3 to PN5 comprises the advanced bell stage; at PN10, it is at the crown stage; at PN21, it is at the functional stage. Therefore, unlike the other major salivary glands, the development of mouse parotid salivary gland is completed through a process of prenatal and postnatal morphogenesis and becomes functional at about the same time as the developing tooth. The developmental completion times of the parotid salivary gland and tooth are closely related to the weaning time of animal.

• Toxicological Research
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• 제3권1호
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• pp.55-63
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• 1987

A Peri-and Postnatal Study was Carried out to examine the effects of rHuIFN-${\alpha}A$, produced by gene-manipulated E. coli, on offsprings of Wistar rats. The substance was administered intraperitoneally to dams at dose levels of $1{\times}10^5$, $4{\times}10^5$ and $1.2{\times}10^6$ I.U/kg/day during the period from day 17 of gestation to day 21 after delivery. All the pregnant dams were allowed to deliver naturally, and the postnatal development of the offsprings was observed. No noticeable toxic effects and pathological changes on dams were observed, and no detectable variations in postnatal development of offsprings occured.

• Clinical and Experimental Pediatrics
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• 제65권1호
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• pp.1-9
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• 2022

With advancements in neonatal care and nutrition, the postnatal growth of preterm infants has improved; however, it remains an issue. Accurate assessments of growth using a standardized reference are needed to interpret the intrauterine and postnatal growth patterns of preterm infants. Growth in the earlier periods of life can contribute to later outcomes, and the refinement of postnatal growth failure is needed to optimize outcomes. Catch-up growth occurs mainly before discharge and until 24 months of age, and very low birth weight infants in Korea achieve retarded growth later in life. Knowing an infant's perinatal history, reducing morbidity rates during admission, and performing regular monitoring after discharge are required. Preterm infants with a lower birth weight or who were small for gestational age are at increased risk of poor neurodevelopmental outcomes. Furthermore, poor postnatal growth is predictive of adverse neurodevelopmental outcomes. Careful monitoring and early intervention will contribute to better development outcomes and national public health improvements.

• 치위생과학회지
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• 제12권5호
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• pp.486-492
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• 2012

치아 발생 동안 법랑질모세포에서의 Dynamin II 단백질 발현 강도는 출생 후 1일째 생쥐에 비해 출생 후 3일째와 출생 후 5일째 생쥐에서 각각 48%와 50%로 유의성 있게 증가하였으나, 출생 후 7일째와 출생 후 10일째 생쥐에서는 출생후 1일째의 생쥐에 비해 각각 16%와 12%로 유의성 있게 감소하였다. 이 결과로부터 Dynamin II가 분비법랑질모세포에서 형성되는 법랑기질 단백질인 amelogenin, ameloblastin, enamelin과 MMP-20 등과의 분비과립 수송에 연관됨이 보여졌다. Dynamin II는 치아 발생과정 중 발현되는 다양한 법랑기질을 구성하는 단백질을 포함하는 분비소포 형성을 촉진함으로써 과립의 수송에 관여할 것이라 생각되며 법랑질모세포에서의 법랑기질 단백질의 분비조절 가능성이 있음이 보여졌다. 따라서 Dynamin II를 통한 치주질환을 위한 유전자 치료와 법랑질 혹은 상아질의 유실 부분의 재생산의 자극과 촉진에도 임상적으로 사용될 수 있는 가능성이 있음이 보여졌다.

• Clinical and Experimental Pediatrics
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• 제55권12호
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• pp.462-469
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• 2012

Purpose: In this study, we aimed to investigate the perinatal clinical conditions of very low birth weight (VLBW) infants born to mothers with pregnancy-induced hypertension (PIH) focusing on the effects of early postnatal neutropenia. Methods: We reviewed the medical records of 191 VLBW infants who were born at Konyang University Hospital, between March 2003 and May 2011. We retrospectively analyzed the clinical characteristics of the infants and their mothers and compared the incidence of perinatal diseases and mortality of the infants according to the presence or absence of maternal PIH and neutropenia on the first postnatal day. Results: Infants born to mothers with PIH showed an increased incidence of neutropenia on the first postnatal day (47.4%), cesarean delivery, and intrauterine growth restriction. When the infants born to mothers with PIH showed neutropenia on the first postnatal day, their incidence of respiratory distress syndrome (RDS) was increased (P=0.031); however, the difference was not found to be significant through logistic regression analysis. In all the VLBW infants, neutropenia on the first postnatal day was correlated with the development of RDS. The incidence of the other perinatal diseases involving sepsis and mortality did not significantly differ according to the presence or absence of neutropenia in infants born to mothers with PIH. Conclusion: In VLBW infants born to mothers with PIH, the incidence of neutropenia on the first postnatal day was increased and it was not significantly correlated with the development of perinatal diseases involving RDS, sepsis, and mortality.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제4권1호
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• pp.79-90
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• 1993

대뇌피질에서 somatostatin 함유 신경세포의 생후 발달과정을 규명하고자 생후 1, 2, 3, 4주 및 2, 3개월의 흰쥐 대뇌를 대상으로 면역조직화학적 염색을 시행하여 신경세포의 형태, 크기 및 분포와 대뇌피질 영역별 세포 수의 변화를 관측하여, 아래와 같은 결과를 얻었다. 1) 형태 및 분포의 변화 생후 1주부터 비교적 염색성이 뚜렷한 다양한 형태의 미성숙 신경세포가 대뇌피질 V, VI층에서 관찰되다가 생후 2주에는 세포질내의 염색성이 균일하게 증가되어 있고 여러개의 돌기를 내는 뭇극성세포가 V, VI층뿐 아니라 제 II층에서도 출현하였다. 생후 3주부터는 신경세포체가 점차 II, III층과 V, VI층에 넓게 분포하였고 미성숙한 신경세포는 II, III층에서 보다 많이 관찰되었으며 생후 4주에는 IV, V, VI층에서의 세포의 감소가 뚜렷하여 주로 II, III, IV층에 분포하는 양상을 보였고 미성숙세포는 거의 관찰되지 않았다. 2) 신경세포체의 크기의 변화 세포체의 크기는 생후 2주를 전후하여 일시적으로 증가하여 최대값을 보이다가 이후 점차 감소하여 생후 8주째에 성숙흰쥐에서의 크기가 되었다. 3) 내뇌피질 영역별 신경세포체 수의 변화 전두, 두정 1, 2, 측두 1, 배모양, 섬피질에서는 생후 1주에서 2주째에 걸쳐 큰 차이없이 세포체의 수가 최대로 증가했다가 이후 성숙흰쥐 수준으로 감소하는 양상을 보였으며 측두 3, 후두, 띠, 코주위 피질에서는 생후 2주째에 최대값을 보였다.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.296.2-296.2
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• 2002

Our previous study demonstrated that 2.3', 4.4'. 5- Pentachlorobiphenyl (PCB 118) showed an antiestrogenic activity in vitro and in vivo. In the present study. we examined the effect of PCB 118 on postnatal reproductive development in female rats. PCB 118 (0.001. 0.01 or 0.1 mg/kg/day) was administered to pregnant female SD rats from gestation day (GO) 6 to 18 via subcutaneous injection. and developmental parameters such as vaginal opening were determined. PCB 118 significantly delayed vaginal opening of female offsprings at dose of 0.1 ${\mu}g$/kg/day. whereas had no effects on body weights. In addition. in utero treatment of PCB 118 caused significant decreases in serum levels of E2, T3 and T4 in female oftsprings at certain doses on postnatal day (PND) 22. Our data of results indicate that in utero exposure to PCB 118 may postnatal reproductive development in female rat through its antiestrogenic activity.

• Asian-Australasian Journal of Animal Sciences
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• 제21권4호
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• pp.510-522
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• 2008

Our earlier studies showed that estrogen was involved in the regulation of fluid reabsorption in adult mouse efferent ductules (ED), through estrogen receptor (ER) ${\alpha}$ and $ER{\beta}$ by modulating gene expression of epithelial genes involved in ion homeostasis. However, little is known about the importance of $ER{\alpha}$ in the ED during postnatal development. Based on previous findings, we hypothesized that there should be a difference in the expression of epithelial ion transporters and anion producers in the ED of postnatal wild type (WT) and estrogen receptor ${\alpha}$ knockout (${\alpha}ERKO$) mice. Using absolute, comparative and semi-quantitative RT-PCR along with immunohistochemistry, we looked at expression levels of several genes in the ED across postnatal development. The presence of estrogen in the testicular fluid was indirectly ascertained by immunohistochemical detection of the P450 aromatase in the testis. There was no immunohistochemically detectable difference in the expression of P450 aromatase in the testes and ER${\beta}$ in the ED of WT and ${\alpha}$ERKO mice. ER${\alpha}$ was only detected in the ED of WT mice. The absence of ER${\alpha}$ in the ED of postnatally developing mice resulted in differential expression of mRNAs and/or proteins for carbonic anhydrase II, $Na^+/H^+$ exchanger 3, down-regulated in adenoma, cystic fibrosis transmembrane regulator, and $Na^+/K^+$ ATPase ${\alpha}$. Our data indicate that the absence of ER${\alpha}$ resulted in altered expression of an epithelial ion producer and transporters during postnatal development of mice. We conclude that the presence of ER${\alpha}$is important for regulation of the ED function during the prepubertal developmental and postpubertal period.

• 대한수의학회지
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• 제52권1호
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• pp.1-8
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• 2012

Histochemical patterns of lectin binding during development of the rat vomeronasal organ (VNO) were studied to determine whether glycoconjugates are differently expressed after birth. Three types of lectins, Dolichos biflorus agglutinin (DBA), wheat germ agglutinin (WGA), and Ulex europaeus agglutinin I (UEA-I), were studied histochemically in the rat VNO at various stages post-birth: postnatal days 1 and 7, the preweaning period (4 weeks after birth), and at sexual maturity (8 weeks after birth). The free border of the vomeronasal sensory epithelium was positive for both WGA and UEA-I in rats of all ages; whereas, VNO receptor cells and supporting cells were positive only for both WGA and UEA-I from 4 weeks after birth. DBA reactivity was detected in the free border but less so in receptor cells and supporting cells. WGA and UEA-I, but not DBA, showed similar patterns in various ages. In the Jacobson's gland, WGA, UEA-I and DBA were detected in some acini from 4 weeks after birth but not at postnatal days 1 or 7. Collectively, reactivity for three lectins, WGA, UEA-I and DBA, increased in receptor cells and gland acini during postnatal development, possibly contributing to the enhanced chemoreception in rats.

• Environmental Analysis Health and Toxicology
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• 제25권4호
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• pp.279-286
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• 2010

Objectives : Platinum nanoparticles (PNPs) are potentially useful for sensing, catalysis, and other applications in the biological and medical sciences. However, little is known about PNP toxicity. In this study, adverse effects of PNPs on the postnatal development of mouse pubs were investigated. Methods : PNPs (size: 20 nm) were prepared and orally administered to mice during premating, gestation, and lactation periods (0.25 mg/kg, 0.5 mg/kg, and 1 mg/kg). Maternal and pup toxicity were evaluated. Results : PNPs did not affect blood biochemical parameters or mortality in dams during the experimental period. Histopathological signs were not observed and pup number was not different between the control and treated groups. Deformity and stillbirth were not observed in the pups. However, PNPs increased pup mortality and decreased the infant growth rate during the lactation period. Conclusion : PNPs may have adverse effects to the postnatal development of mouse pups.