• Animal Bioscience
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• 제37권5호
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• pp.839-851
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• 2024

Objective: The main goal of our current study was to improve the growth curve of meat animals by decreasing the birth weight while achieving a finishing weight that is the same as that before selection but at younger age. Methods: Random regression model was developed to derive various selection indices to achieve desired gains in body weight at target time points throughout the fattening process. We considered absolute and proportional gains at specific ages (in weeks) and for various stages (i.e., early, middle, late) during the fattening process. Results: The point gain index was particularly easy to use because breeders can assign a specific age (in weeks) as a time point and model either the actual weight gain desired or a scaled percentage gain in body weight. Conclusion: The point gain index we developed can achieve the desired weight gain at any given postnatal week of the growing process and is an easy-to-use and practical option for improving the growth curve.

• Applied Microscopy
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• 제31권4호
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• pp.355-365
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• 2001

흰쥐 전뇌 기저부에서 콜린성 신경세포는 내측중격핵, 수직 및 수평 대각 Broca대, 거대세포 시교차앞핵, 복부담창구, Meynert기저핵 그리고 신선조체 등에 분포하는 것으로 알려져 있다. 저자 등은 흰쥐 전뇌 기저부 Meynert 기저핵에서 ChAT항체를 이용한 면역조직 및 세포화학적 방법으로 신경세포들의 발생, 분포, 형태, 형별 출현율 및 세포체의 부피, 조직학적 특성 등을 확인하였다. 또한 전자현미경을 이용하여 ChAT항체에 면역 반응을 하는 신경세포의 미세구조적 특징을 관찰하여 출생 후 발생단계에 따른 Meynert 기저핵에서 ChAT항체 면역반응 신경세포들의 분화를 관찰하고 다음과 같은 결과를 얻었다. ChAT항체에 반응하는 신경세포의 분포는 조직마다 부분적으로 상이하지만, 대부분 담창구가 내포와 접하는 부위, 또는 담창구와 무명질의 연접지역에 군집을 이루거나 혹은 단독으로 관찰되었으며 ,무명질에는 시교차앞핵의 면역반응 세포와 혼재하는 것으로 확인되었다. ChAT면역반응 신경세포들은 세포의 모양과 세포체의 장 단축의 비에 따라 6가지형으로 분류되었다. 원형의 신경세포 출현율은 출생 후 7일에서 가장 높았고, 성체로 되면서 점차적으로 감소하였으며, 난형 신경세포는 출생 후 14일에 가장 높게 나타났고, 원형의 신경세포와 같이 성체로 되면서 점차 감소하였다. 또한, 세장형 신경세포의 출현 율은 출생 후 21일에 가장 높게 나타났다. 삼각형, 방추형 그리고 다각형 신경세포는 성체에서 출현율이 높았다. ChAT면역반응 신경세포체의 부피는 출생 후 7일에 $1,268{\mu}m^3$로 제일 작았으나, 출생 후 21일에서는 $4,453{\mu}m$로 최대치를 보였다. 그 후 성체로 되면서 점차 감소되었다. 전자현미경 관찰에서 성체의 ChAT항체 반응 신경세포의 핵외막, rER의 막, 자유리보즘 그리고 polysorne등이 관찰되었으며, 대칭 및 비대칭 신경연접이 관찰되었다. 이상의 결과들로 미루어 흰쥐 전뇌 기저부 Meynert기저핵에서의 ChAT면역반응 신경세포들은 출생 후 발생과정에서 세포소기관과 신경돌기들의 분화에 따른 세포체 부피의 증가, 분화된 세포형들의 출현 율의 증가 및 세포의 손실이 없는 상태에서 세포 응축 등의 과정을 통하여 세포들이 분화한다고 생각된다.

• Journal of Animal Science and Technology
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• 제49권3호
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• pp.309-320
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• 2007

본 연구에서는 남성 생식 기관인 efferent ductules(ED)에서 monocarboxylate transporter (MCT) isoform과 Basigin(Bsg)의 mRNA 발현을 탐구하고, MCT1의 발현이 에스트로젠 수용체 α에 의해 조절되는지를 연구하였다. 생후 여러 연령대의 백서 ED에서 MCT isoform과 Bsg의 mRNA 발현 여부는 real-time PCR에 의해 조사 되었고, 정상 생쥐와 에스트로젠 수용체 α knockout 생쥐를 사용하여 에스트로젠 수용체 α에 의한 MCT1의 발현 조절 여부는 immunohistochemistry 방법에 의해 간접적으로 알아 보았다. 본 연구 결과는 백서의 ED에서 MCT1, 2, 3, 4와 8 그리고 Bsg 유전자의 발현은 연령에 따라 다르게 나타나며, MCT1의 발현이 ED의 ciliated 세포의 basolateral 지역에서 발현되고 어떤 측면에서 ERα에 의해 조절되어 질 수 있음을 보여 주었다. 따라서 본 연구 결과는 MCT가 monocarboxylate의 세포 내, 외부로 운반을 조절함으로써 남성 생식기의 일부인 ED의 역할을 조절하는데 관여함을 시사한다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권5호
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• pp.742-752
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• 2020

Objective: This study investigated the effects of vitamin A (VA) supplementation during late-stage pregnancy on longissimus dorsi muscle tissue development, birth traits, and growth performance of postnatal Korean native calves. Methods: In the preliminary experiment, twenty-six pregnant cattle (initial body weight [BW] = 319 kg (standard deviation [SD] = 30.1; 1st parity) were randomly assigned to the control and treatment groups. The treatment group received VA supplementation at 24,000 IU/d from gestational day 225 until delivery. In the main experiment, twelve pregnant cattle (initial BW = 317 kg [SD = 31.3]; 1st parity) were treated with VA supplementation at 24,000 IU/d (gestational days 150 to 225) and at 78,000 IU/d (gestational day 225 until delivery). Serum VA levels were analyzed in pregnant cattle, and the growth performance, gene expression, and serum VA levels were analyzed in the offspring. Results: Serum VA levels in pregnant cattle decreased the late gestation in both experiments (p<0.001). In the main experiment, pregnant cattle at parturition and offspring at birth in the treatment group had higher serum VA levels than those in the control group (p<0.05). In the treatment groups, an increased birth weight was observed in the main experimental group (p = 0.022), and a tendency (p = 0.088) toward an increased birth weight was observed in the preliminary experimental group. However, no differences were observed in the feed intake, average daily gain, gain-to-feed ratio, or BW of 31-day-old calves. Gene expression was analyzed in longissimus dorsi muscles of 31-day-old calves. VA supplementation in pregnant cattle stimulated postnatal muscle development in offspring by elevating myogenic factor 5 (MYF5), MYF6, and myoblast determination levels (p<0.05). Moreover, preadipocyte-related marker genes such as extracellular signal-regulated kinase 2 and krüppel-like factor 2 were higher in the treatment group than in the control group (p<0.05). Conclusion: VA supplementation (78,000 IU/d) in late-stage pregnant cattle maintained serum VA levels. In addition, 78,000 IU/d VA supplementation increased the birth weight and expression of genes related to muscle and preadipocyte development in offspring. Overall, 78,000 IU/d VA supplementation in pregnant cattle is beneficial to newborn calves.

• 대한수의학회지
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• 제37권4호
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• pp.693-706
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• 1997

The present study was designed to investigate the morphological developments of the stomach in the prenatal and postnatal rats. The gastric fundus of 16- to 22-day-old fetuses, neonates, 7-day-old, 14-day-old, 21-day-old, and adult rats were observed by light and scanning electron microscopy. Light microscopic studies. 1. In the 16-day-old fetuses, the walls of the gastric fundus were differentiated into epithelium, lamina propria, muscle layer, and serosa. The lamina propria was composed of mesenchymal connective tissue cells with sparse nucleus and their fibers. 2. In the 17-day-old fetuses, the muscular layer were differentiated into the circular and longitudinal muscle layers. 3. The epithelium on the fundus of stomach was stratified columnar cells at 16-, 17- and 18-day-old fetuses, but partly converted into simple columnar epithelium at 19-day-old fetuses. 4. The mucous cells were positive by PAS reaction at the 19-day-old fetuses and then these developed rapidly within 1 or 2 days before birth. 5. In the 20-day -old fetuses, the parietal cells were distinguished from other type cells and these cells were chiefly crowded in the middle parts of the gastric glands after 7-day-old. Scanning electron microscopic studies. 6. The surface of gastric mucosa was covered with forms of the various protrusions by forming villi at the last few days before birth and these protrusion forms were fused and folded each other. 7. The mucosal surface was closely packed by polygonal mucous cells. The openings of gastric glands were seen as slit-like round invagination and were more numerous and increased gradually in depth after the postnatal life. The above findings indicate that prominent changes occurred in the pattern of cellular proliferation in the stomach fundus at the end of gestation. The gastric epithelium had well-defined glands composed of parietal, chief and mucous cells just before the birth. The stomach fundus, therefore, were developed morphologically as those of normal adult at fourteen days after birth.

• Clinical and Experimental Pediatrics
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• 제52권8호
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• pp.888-892
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• 2009

목 적 : 신생아실에서 만삭아에 준한 경과 관찰 후 퇴원한 후기 조산아들의 재입원과 관련된 위험 요인과 재입원 원인을 알고자 연구를 계획하였다. 방 법 : 2003년 1월부터 2008년 12월까지 일신 기독 병원 신생아실에서 만삭아에 준한 경과 관찰 후 퇴원한 후기 조산아들 중 생후 28일 이내에 재입원하였던 135명의 신생아들의 의무 기록지를 후향적으로 조사하였다. 재입원의 위험 요인을 알고자 대조군과 비교 분석하였다. 결 과 : 재입원과 관련된 위험 요인 연구에서 재태주수, 출생 체중, 성별, 분만 방법, 산모의 나이, 교육 정도, 결혼 여부, 진통과 분만 과정상의 합병증은 관련이 없었고, 모유 수유(71.9% vs 44.4%), 짧은 신생아실 경과 관찰 기간($3.3{\pm}1.6$일 vs $4.1{\pm}2.0$일), 초산모(60.0% vs 45.3%)와 임신 합병증이 있었던 경우(31.9% vs 18.8%) 통계적으로 유의하게 재입원율이 높았다. 재입원 시점은 출생 후 평균 $6.2{\pm}3.6$일로, 출생 5-6일 사이에 재입원하는 경우가 40.7%로 가장 많았다. 재입원 시 83.7%가 황달을 주소로 입원하여 가장 흔한 원인이었고, 자연 분만(43.4% vs 1.8%), 산모의 나이가 적은 경우($29.8{\pm}3.4$세 vs $32.1{\pm}4.2$세), 임신과 관련된 합병증 동반이 적은 경우(28.3% vs 50%)가 황달로 인한 재입원과 관련 있었다. 결론 : 후기 조산아들의 재입원과 관련된 위험 요인은 모유 수유, 짧은 신생아실 경과 관찰 기간, 초산모와 임신 합병증이 있었던 경우였고, 재입원 시점은 평균 $6.2{\pm}3.6$일, 가장 흔한 재입원 원인은 황달이었다.

• Clinical and Experimental Pediatrics
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• 제52권9호
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• pp.1053-1058
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• 2009

거대세포바이러스(CMV)는 신생아에서 가장 흔한 선천성 감염의 원인 중 하나이며, 모든 정상 출산아 중 약 0.3-2.4%에서 감염되어 있다. 혈청에서 거대세포바이러스 양성인 모체 중 40-96%에서 모유를 통한 바이러스의 배출이 증명되었으며, 거대세포바이러스에 감염된 모유를 통한 감염은 전체 영아 거대세포바이러스 감염의 약 1/3을 차지한다. 본 증례에서는 극소 저체중 출생아에서 모유를 통하여 발생한 거대세포바이러스 감염을 기술하였다. 환아는 생후 7일 경부터 모유 수유를 하였으며, 심한 혈소판감소증, 빈혈, 그리고 패혈증과 유사한 임상 양상에 대하여 반복되는 혈소판 수혈, 적혈구 수혈, 면역 글로불린 요법을 시행받았다. 거대세포바이러스 감염은 생후 2개월 경 혈청 CMV IgM 양성 및 소변 CMV 배양 검사 양성 소견을 통하여 진단하였다. 출생 당시 혈청 CMV IgM 및 소변 CMV 배양 검사가 음성이었으므로 선천성 감염은 배제할 수 있었다. 환아의 혈청과 모유의 핵산 배열 순서 분석을 통하여 동일한 바이러스에 의한 감염임을 증명하였다. 저자들은 국내에서 최초로 nucleotide sequencing 방법을 이용, 모유 수유를 통한 거대세포바이러스 감염이 발생한 극소 저체중 출생아의 예를 보고하는 바이다.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1077-1086
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• 2020

Objective: We examined the localization and expression of H⁺ pumping vacuolar ATPase (V-ATPase) and cytokeratin 5 (KRT5) in the epididymis of pigs, expressed in clear and basal cells, respectively, during postnatal development. Methods: Epididymides were obtained from pigs at 1, 7, 21, 60, 120, and 180 days of age; we observed the localization and expression patterns of V-ATPase and KRT5 in the different regions of these organs, namely, the caput, corpus, and cauda. The differentiation of epididymal epithelial cells was determined by immunofluorescence labeling using cell-type-specific markers and observed using confocal microscopy. Results: At postnatal day 5 (PND5), the localization of clear cells commenced migration from the cauda toward the caput. Although at PND120, goblet-shaped clear cells were detected along the entire length of the epididymis, those labeled for V-ATPase had disappeared from the corpus to cauda and were maintained only in the caput epididymis in adult pigs. In contrast, whereas basal cells labeled for KRT5 were only present in the vas deferens at birth, they were detected in all regions of the epididymis at PND60. These cells were localized at the base of the epithelium; however, no basal cells characterized by luminally extending cell projections were observed in any of the adult epididymides examined. Conclusion: The differentiation of clear and basal cells progressively initiates in a retrograde manner from the cauda to the caput epididymis. The cell-type-specific distribution and localization of the epithelial cells play important roles in establishing a unique luminal environment for sperm maturation and storage in the pig epididymis.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.163-166
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• 2018

Objective: Microminipigs are a novel animal model with extensive applications in laboratory studies owing, in part, to their extremely small body sizes. In this study, the relationship between swine leukocyte antigen (SLA) class II haplotype and body weight was evaluated in the Microminipig population. Methods: A total of 1,900 haplotypes, covering SLA class II haplotypes Lr-0.7, Lr-0.23, Lr-0.17, Lr-0.37, Lr-0.16, Lr-0.11, Lr-0.13, and Lr-0.18, were analyzed in 950 piglets. Birth weights and weights on postnatal day 50 were examined in piglets with eight different SLA class II haplotypes. Results: The mean birth weight of piglets with the Lr-0.23 haplotype (0.415 kg, n = 702) was significantly lower than that of piglets with Lr-0.17 (0.445 kg, n = 328) and Lr-0.37 (0.438 kg, n = 383) haplotypes. At postnatal day 50, the mean body weight of piglets with the Lr-0.23 haplotype (3.14 kg) was significantly lower than that of piglets with the Lr-0.13 haplotype (3.46 kg, p<0.01). There were no significant differences in daily gains (DGs) among the eight haplotypes. However, piglets with the Lr-0.11 and -0.18 haplotype combination or any heterozygous haplotype combinations containing Lr-0.23 had significantly lower DGs than those of piglets with the Lr-0.18, 0.37 haplotype combination. Conclusion: Piglets with the Lr-0.23 haplotype had relatively low body weights at birth and on postnatal day 50 and slightly lower DGs than those of piglets with other haplotypes. Therefore, the Lr-0.23 SLA class II haplotype may be a suitable marker for the selective breeding of Microminipigs with small body sizes.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.471-482
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• 2009

Nutrient availability may control muscle growth directly and indirectly through its influence on regulatory factors. We analyzed the effects of nutrient availability on the breast muscle insulin-like growth factor system. Real time RT-PCR was used to quantify the level of transcription in breast muscle from Langshan (LS) layer and Arbor Acres (AA) broiler chickens subjected to different feeding regimens during embryonic and postnatal development. The AA chickens were fed AA diet (AA, control group) while the LS chickens were either fed LS diet (LL) or AA diet (LA). According to our results, insulin-like growth factor (IGF)-II (embryonic day 16 (E16) - postnatal day 42 (P42)), IGF-I receptor (IGF-IR, E18-P42), and IGF binding protein (IGFBP)-2 (E18-P42), -5 (E16-P14), -7 (E12-P0), and -3 (E12-P0) were positively correlated with IGF-I, while IGFBP-3 (P0-P28) was negatively correlated with IGF-I. In comparison, IGF-IR (E18-P42), IGFBP-2 (E18-P42), IGFBP-5 (E14-P0), and IGFBP-3 (E16-P0) were positively correlated with IGF-II, while IGF-IR (E10-E16) and IGFBP-3 (P0-P28) were negatively correlated with IGF-II. Moreover, IGFBP-2 (E16-P42), -7 (E10-E16), and -3 (E10-E16) were positively correlated with IGF-IR, while IGFBP-3 (P0-P28) was negatively correlated with IGF-IR. Finally, IGFBP-7 (E12-P0) was positively correlated with IGFBP-3, while IGFBP-2 (P0-P28) and -7 (P0-P42) were negatively correlated with IGFBP-3. Overall, the AA chickens exhibited higher levels of IGF-I, IGF-IR, and IGFBP-2 mRNA expression than the LL chickens, while the opposite was true for IGFBP-7. No strain differences in IGF-I, IGF-IR, and IGFBP-7 mRNA expression were detected between LA and AA chickens; however, a strain difference was observed for IGFBP-2. LA chickens exhibited higher levels of IGFBP-2 than LL chickens, while the opposite was true for IGFBP-7. Our data show the first evidence that certain genes may be correlated during specific developmental periods and that strain differences in the expression of those genes in LS and AA chickens are due to differential responses to the same diet.