• Current Research on Agriculture and Life Sciences
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• 제4권
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• pp.102-108
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• 1986

본 시험에서는 저수태우로 판단된 우수한 형질의 젖소를 공란우로 사용하여 과배란처리에 대한 반응 및 수태율에 영향을 주는 계절, 연령, 생식기관내의 이상유무 및 반복사용에 따른 반응을 검토하였던 바 그 결과는 다음과 같다. 1. 이른 봄(2월~4월)이 좋은 수정란 생산에 제일 좋았으며 수태율은 2월에서 7월까지는 좋았으나 그 이후 저하되었다. 2. 공란우 생식관내의 이상이 있는 경우는 과배란처리 반응 및 수태율이 예상대로 정상우보다 나빴다. 3. 8세우가 4세우보다 수태율이 높았고, 과배란처리 반응에서도 8세우가 4세우보다 약간 좋은 결과를 보였다. 4. 과배란처리 횟수가 많을 수록 첫 번째 과배란처리 보다 배란수(32:41) 및 수태율(68.4:85.7%)이 증가되었다.(단 3차반복까지) 5. 6두의 공란우에서 9회의 채란을 하여 좋은 수정란 38개를 생산했고, 이중 33개를 이식하여 25두가 임신되었다. 6. 본 실험에서 저수태우를 수정란 이식을 위한 공란우로 재이용하여 그 경제성을 높일 수 있는 가능성을 확실히 제시하고 있다.

• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2005년도 추계학술대회 초록집
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• pp.88-88
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• 2005

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1999년도 학술발표논문집
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• pp.183-186
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• 1999

오이재배는 초기에 노지직파재배와 조숙재배가 주된 작형이었으나, 플라스틱하우스재배와 함께 새로운 품종육성 및 보급으로 현재는 시설재배를 중심으로 한 재배작형이 다양하게 분화 발전되고 있다. 우리나라에서는 종묘회사가 다다기성, 내서성, 내병성 등을 개선하고 각 재배방식의 환경에 알맞은 우수한 1대 잡종 품종들을 많이 육성하여 보급하고 있다. 1996년 8월 현재 등록된 오이품종은 171품종이다. (중략)

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Molecular and Cellular Response to Toxic Substances
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• pp.60-66
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• 2002

Aryl hydrocarbons, environmental contaminants accumulate in tissue and pose potential risk in human health. 2,3,7,8-Tertachlorodibenzo-p-dioxin (TCDD) is known as a most potent toxicant among aryl hydrocarbons. TCDD elicits numerous toxic responses in experimental animals and human, including hepatic carcinoma, pulmonary and skin tumor in adult rodents, craniofacial abnormality during mouse embryogenesis, chloracne, reproductive abnormality, immunotoxicity, endocrine effects in exposed humans.(omitted)

• 한국발생생물학회지:발생과생식
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• 제20권2호
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• pp.91-99
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• 2016

Lipopolysaccharide (LPS), an endotoxin, elicits strong immune responses in mammals. Several lines of evidence demonstrate that LPS challenge profoundly affects female reproductive function. For example, LPS exposure affects steroidogenesis and folliculogenesis, resulting in delayed puberty onset. The present study was conducted to clarify the mechanism underlying the adverse effect of LPS on the delayed puberty in female rats. LPS was daily injected for 5 days ($50{\mu}g/kg$, PND 25-29) to treated animals and the date at VO was evaluated through daily visual examination. At PND 39, animals were sacrificed, and the tissues were immediately removed and weighed. Among the reproductive organs, the weights of the ovaries and oviduct from LPS-treated animals were significantly lower than those of control animals. There were no changes in the weights of uterus and vagina between the LPS-treated and their control animals. immunological challenge by LPS delayed VO. Multiple corpora lutea were found in the control ovaries, indicating ovulations were occurred. However, none of corpus luteum was present in the LPS-treated ovary. The transcription level of steroidogenic acute regulatory protein (StAR), CYP11A1, CYP17A1 and CYP19 were significantly increased by LPS treatment. On the other hand, the levels of $3{\beta}$-HSD, $17{\beta}$-HSD and LH receptor were not changed by LPS challenge. In conclusion, the present study demonstrated that the repeated LPS exposure during the prepubertal period could induce multiple alterations in the steroidogenic machinery in ovary, and in turn, delayed puberty onset. The prepubertal LPS challenge model used in our study is useful to understand the reciprocal regulation of immune (stress) - reproductive function in early life.

• 한국작물학회지
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• 제47권5호
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• pp.390-394
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• 2002

Spikelet number per unit area(SPN) is a major determinant of rice yield. Nitrogen nutrition status and biomass during reproductive stage determine the SPN. To formulate a model for estimating SPN, the 93 field experiment data collected from widely different regions with different japonica varieties in Korea and Japan were analyzed for the upper boundary lines of SPN responses to nitrogen nutrition index(NNI), shoot dry weight and shoot nitrogen content at panicle initiation and heading stage. The boundary lines of SPN showed asymptotic responses to all the above parameters(X) and were well fitted to the exponential function of $f(X)=alphacdot{1-etacdotexp(gamma;cdot;X)}$. Excluding the constant, from the boundary line equation, the values of the equation range from 0 to 1 and represent the indices of parameters expressing the degree of influence on SPN. In addition to those indices, the index of shoot dry weight increase during reproductive stage was calculated by directly dividing the shoot dry weight increase by the maximum value ($800 extrm{g/m}^{-2}$) of dry weight increase as it showed linear relationship with SPN. Four indices selected by forward stepwise regression at the stay level of 0.05 were those for NNI ($I_{NNI}_P$) at panicle initiation, NNI($I_{NNI}_h$) and shoot dry weight($I_{DW}_h$) at heading stage, and dry weight increase($I_{DW}$) between those two stages. The following model was obtained: SPN=48683ㆍ $I_{DWH}$$^{0.482}$ㆍ $I_{NNIp}$$^{0.387}$ㆍ $I_{NNIH}$$^{0.318}$ㆍ $I_{DW}$ $^{0.35}$). This model accounted for about 89% of the variation of spikelet number. In conclusion this model could be used for estimating the spikelet number of japonica rice with some confidence in widely different regions and thus, integrated into a rice growth model as a component model for spikelet number estimation.n.n.

• 한국발생생물학회지:발생과생식
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• 제13권3호
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• pp.133-143
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• 2009

Pivotal roles of steroid hormones in uterine endometrial function are well established from the mouse models carrying the null mutation of their receptors. Literally androgen belongs to male but interestingly it also detected in female. The fluctuations of androgen levels are observed during reproductive cycle and pregnancy, and the functional androgen receptor is expressed in reproductive organs including uterus. Using high throughput methodology, the downstream genes of androgen have been isolated and revealed correlations between other steroid hormones. In androgen-deficient mice, uterine responses to exogenous gonadotropins are impaired and the number of pups per litter is reduced dramatically. As expected androgen has important role in decidual differentiation through AR. It regulates specific gene network during those cellular responses. Recently we examined the effects of steroid hormonal complex containing high level of androgen. Interestingly, on the contrary to the androgen-alone administration, the hormonal complex did not disturb the decidual reaction and the pubs did not show any morphological abnormality. It is suspected that the complexity of communication between other steroid hormone and their receptors are the reasons. In summary, androgen exists in female blood and it suggests the importance of androgen in female reproduction. However, the complex interactions with other hormones are not fully understood compared with estrogen and progesterone. The further studies to evaluate the possible role of androgen are needed and important to provide the in vivo rational for the prevention of associated pregnancy complications and help human's health.

• Clinical and Experimental Reproductive Medicine
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• 제21권3호
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• pp.241-245
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• 1994

Despite increasing success rate of IVF, poor response to ovarian stimulation remains a problem. So, attempts to improve ovarian responses, for example, by using combined gonadotropin-releasing hormone analogue(GnRH-a) and human menopausal gonadotropin(hMG) have shown limited success. It is reported that response of granulosa cells in vitro to FSH is stimulated by co-incubation with IGF-l, and IGF-l production can be increased by growth hormone. This suggest that combination regimen of G.H. and hMG may augment follicle recruitment. In fifteen patients who had previous history of poor ovarian response to gonadotropin stimulation after pituitary suppression with mid -luteal GnRH-a, the effectiveness of cotreatment with G.H. in IVF program was evaluated using a combination regimen of G.R. and hMG at Korea University Hospital IVF Clinic. Ovarian responses to gonadotropin stimulation in control and GH-treated cycles assessed by total dose and duration of hMG treatment, follicular development and peak $E_2$ level, number of eggs retrieved, and fertilization rates were also assessed. In each group, serum and follicular fluid IGF-1 concentrations on day of egg collection were measured by RIA after acidification and extraction by reveresed phase chromatography. Patients receiving G.H. required fewer days and ampules of gonadotropins, developed more oocytes, and more embryos transferred. But, the differences were not statistically significant, except the duration of hMG treatment. Our data showed a significantly higher concentration of IGF-l in the serum, not in the follicular fluid, of patients treated with G.H. compared with control group. These data suggest that growth hormone treatment does not improve the ovarian response in women with limited ovarian reserve to gonadotropin stimulation for IVF.

• 대한수의학회지
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• 제35권3호
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• pp.603-613
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• 1995

Plasma progesterone($P_4$) assay has been introduced to apply to the differential diagnosis of reproductive disorders and the monitoring of responses of ovarian dysfunction to $PGF_2{\alpha}$ or GnRH treatment in the 204 postpartum and postinsemination subestrus dairy cows. 1. The incidence rate of reproductive disorders in 204 subestrus cows, diagnosed by palpation per rectum and plasma $P_4$ determination using 'Two sample test'(Day 0+Day 10) were as follows; silent heat or error of estrus detection 110(53.9%), persistent corpus luteum 26(12.7%), follicular cyst 16(7.8%), inactive ovary 12(5.9%), luteal cyst 11(5.4%), granulosa cell tumor of ovary 1(0.5%), fetal mummification 1(0.5%), endometritis 15(7.4%) and pyometra 12(5.9%), respectively. 2. After the $PGF_2{\alpha}$ treatment to the 76 cows with silent heat or error of estrus detection, persistent corpus luteum, or luteal cyst, plasma $P_4$ concentrations at day 3 post treatment using 'Two sample test'(Day 0+Day 3) remained low(<1.0ng/ml) in all 76 cows. Therefore all 76 cows responded positively to $PGF_2{\alpha}$ treatment. Seventeen cows with follicular cyst or inactive ovary were treated with GnRH. All 7 cows with follicular cyst and 4 cows with inactive ovary remained high($${\geq_-}1.0ng/ml$$) a plasma $P_4$ concentrations at day 12 post treatment using 'Two sample test'(Day 0+Day 12), but 6 cows with inactive ovary remained low(<1.0ng/ml) a plasma $P_4$ concentrations. Therefore all 7 cows with follicular cyst and 4 cows with inactive ovary responded positively, but 6 cows with inactive ovary responded negatively to GnRH treatment. 3. The mean days from treatment to first service, number of cows conceived on first service(%), mean number of services per conception, mean days from initial treatment to conception, and mean number of cows conceived by 100 days post treatment(%) were 5.0 and 26.2 days, 45(59.2%) and 6(35.3%) cows, 1.5 and 1.7 services, 13.6 and 22.6 days, and 62(81.6%) and 9(52.9%) cows in group of $PGF_2{\alpha}$ and GnRH treatment, respectively. These results indicated that plasma $P_4$ assay was practical as an aid to diagnosing reproductive disorders and to monitoring responses of ovarian dysfunction to $PGF_2{\alpha}$ and GnRH treatment in subestrus cows.

• Molecular & Cellular Toxicology
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• 제1권2호
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• pp.78-86
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• 2005

Dioxins, especially 2, 3, 7, 8-Tetrachlorodibenzo-p-dioxin (TCDD or dioxin), are ubiquitous environmental contaminants. TCDD is known that it has toxic effects in animals and humans, including chloracne, immune, reproductive and developmental toxicities, carcinogenicity, wasting syndrome and death. TCDD induces a broad spectrum of biological responses, including disruption of normal hormone signaling pathways, reproductive and developmental defects, immunotoxicity, liver damage, wasting syndrome and cancer. Many researches showed that TCDD induces gene expression of transcriptional factors related cell proliferation, signal transduction, immune system and cell cycle arrest at molecular and cellular levels. These toxic actions of TCDD are usually mediated with AhR (receptor, resulted from cell culture, animal and clinical studies). cDNA microarray can be used as a highly sensitive and informative marker for toxicity. Additionally, microarray analysis of dioxin-toxicity is able to provide an opportunity for the development of candidate bridging biomarkers of dioxin-toxicity. Through microarray technology, it is possible to understand the therapeutic effects of agonists within the context of toxic effects, classify new chemicals as to their complete effects on biological systems, and identify environmental factors that may influence safety.