• Asian-Australasian Journal of Animal Sciences
• /
• 제21권8호
• /
• pp.1103-1108
• /
• 2008

An investigation to determine frequency and distribution of folate sensitive chromosomal fragile sites was carried out in a Pakistani breed of Lohi sheep to uncover fragile site phenomena. The means and standard errors of aberrant cell count (AC) and Number of aberrations (NoA) in Lohi sheep were $0.56{\pm}0.15$ and $0.59{\pm}0.16$ in the control cultures. FUdR treated cells showed significantly higher (p<0.001) AC and NoA means ($2.18{\pm}0.33$ and $2.65{\pm}0.50$). The sex comparison for the frequency of expression indicated that males had significantly higher number of aberrant cells and total number of aberrations in FUdR cultures than the female group in Lohi sheep. The comparison of control cultures was however, not significantly different between the two groups. The regression analysis of FUdR-induced chromosomal fragility data analysis of the fragility data predicted very low ${\beta}$ of 0.325 and 0.412 for AC and NoA respectively. Lohi chromosomes expressed lesions in only 7 and 24 bands in the control and FUdR cultures respectively. The total number of significantly fragile bands in the Lohi genome was only 4. The X-chromosome of the Lohi sheep was highly stable at $5{\mu}g/ml$ FUdR with no fragile sites. The sex comparison for the distribution of fragile sites across the Lohi genome did not reveal any noticeable differences.

• 한국안광학회지
• /
• 제6권2호
• /
• pp.1-9
• /
• 2001

본 논문에서는 기존에 설계된 복사기 줌 렌즈계를 선택하여 광학적 성능을 계산하여 분석하여 보았다. 이 렌즈계는 유한 물점에 대한 zoom 렌즈계로서 우리가 일반적으로 사용하는 무한 물점에 대한 카메라 zoom 렌즈와는 달리, 고정된 물체와 상면사이에서 움직이기 때문에 제한된 이동영역을 갖게 된다. 대칭형과 비대칭형의 두 복사기 렌즈계의 광학적 성능을 비교 분석한 결과, 비대칭형이 비교적 안정된 수차량을 이루고 있고, 수차보정을 위하여 많은 노력이 있었음을 알 수 있었다. 이것으로 미루어 보아 대칭형은 고정 초점 렌즈계에서는 대칭형의 특성상 자동으로 개선되는 수차들로 인하여 그 역할을 충분히 감당하고 있지만, 줌 렌즈계로 사용 시에는 대칭형을 유지하면서 그 성능을 개선시키는 데에는 한계가 있다고 볼 수 있다.

• 한국광학회지
• /
• 제11권4호
• /
• pp.239-245
• /
• 2000

본 논문에서는 회절광학소자를 이용하여 컴팩트형 디지털 스틸 카메라용 광학계를 설계 및 평가하였다. 기존의 디지털 스틸 카메라용 광학계가 retrofocus 형태인 것에 비해 컴팩트한 광학계를 얻기 위해서 telephoto 형태로 구성하였다. 또한, 본 광학계를 회절광학소자와 굴절광학소자가 결합된 hybrid 플라스틱 렌즈 1매와 순수한 굴절광학소자 1매로 구성하여 무게, 부피등을 줄이고자 하였다. Gauss 괄호를 이용한 근축 광선추적을 통해 초기 설계치를 수치 해석적인 방법으로 구하였다. 제1면을 비구면화하고, 색수차를 보정하기 위해 제2면을 회절광학소자를 이용하여 설계된 광학계는 1/4" CCD, F/4에 대응되도록 최적화하였다. 최종적으로 설계된 광학계의 초점거리는 3.89mm, 전장(overall length)은 5.19mm로서 컴팩트하며, 현재의 디지털스틸 카메라용 광학계에서 요구하는 성능을 충분히 만족하며, 차세대 화상통신용 광학계에 응용될 수 있을것으로 기대된다.

• Archives of Pharmacal Research
• /
• 제28권9호
• /
• pp.1079-1085
• /
• 2005

The purpose of this study was to investigate the safety of chitosan oligosaccharide and the effects of chitosan oligosaccharide on mercury induced genotoxicity in mice using the micronuclei and chromosome aberration. The micronuclei test was performed by microscopic examination $(\times1,000,\;stained\;using\;a\;May-Grunwald\;solution)$ after administering 0.01, 0.1, and $1\%(10\;mg/mL)$ chitosan oligosaccharide for 7, 60, and 180 days ad libitum in mice. Total micronuclei of 1,000 polychromatic erythrocytes were recorded for each group. There was no difference between the untreated and experimental groups. The intake periods and concentrations of chitosan oligosaccharide did not affect the occurrence of micronuclei in bone marrow cells (P>0.05). The chromosomal aberration test was performed by microscopic examination $({\times}1,000,\;stained\;using\;a\;4\%\;Giemsa\;solution)$ after administering the same concentration of chitosan oligosaccharide to mice, in $F_1,\;F_2,\;F_3$ generations and parents. The frequency of chromosomal aberrations was defined as [Ydr=(D+R)/total number of counted lymphocytes]. Similar to the micronuclei test, there was no difference between the untreated and treated groups. These results showed that the intake periods and concentrations of chitosan oligosaccharide did not affect chromosomal aberrations in bone marrow cells (P>0.05). To investigate the effect of chitosan oligosaccharide on mercury-induced chromosome aberration, mice in each condition were supplied with $^{203}HgCl_2$ and chitosan oligosaccharide ad libitum. Chitosan oligosaccharide significantly inhibited $^{203}HgCl_2-induced$ chromosome aberration in mice. Based on the results of this study, it may be concluded that the chitosan oligosaccharide is a nontoxic material that could be used as a suppressor of heavy metal-induced genotoxicity.

• 한국환경보건학회지
• /
• 제24권2호
• /
• pp.88-99
• /
• 1998

This study was undertaken to find out the bio-effects due to be a radiation fractionated exposure. The experimental animals were divided into the control group and the radiation exposure groups of 20cGy, 40cGy and 80cGy with 220 male Sprague-Dawley rats at 6 weeks old. The radiation exposure groups were fractionated exposed from each 20cGy, 40cGy and 80cGy for every 5 days. The chromosome aberrations, the frequency of SCE, the changes of body weight, hematological values and enzyme activities were investigated for the fractionating exposure times and the time after fractionated exposure. The results were summarized as follows 1. The body weight of the radiation exposure groups were significantly decreased compared with control group according to the increasing fractionated exposure times, and it was the lowest values at the immediately after the end of the fractionating exposed, but it was recovered with the level of control group at 3rd weeks gradually increased 1st week after fractionated exposure. 2. The values of WBC, RBC, Hb and Hct in the radiation exposure groups were significantly decreased than those the control group, but the values of GOT, GPT, ALP, and LDH in the radiation exposure groups were significantly increased than those of the control group. 3. The frequency of chromosomal aberration were increased according to the increasing fractionated exposure dose, and it showed the highest at 5th days after fractionated exposed. The types of chromosomal aberration were occurred such as a numerical abnormality, deletion, break and duplication, it was not recovered immediately and maintained high frequency than the control group. 4. The frequency of SCE were significantly increased according to the increasing fractionated exposure dose in 20cGy, 40cGy and 80cGy groups. But it was recovered the level of control group at 7th days after fractionated exposure. According to the above results, this study could confirm that the frequency of chromosomal aberration and SCE were increased with fractionated exposure dose, the other hand, the changes of body weight, hematological values and enzyme activity values were significantly affected according to the increasing fractionated exposure dose.

• 한국가축번식학회지
• /
• 제26권4호
• /
• pp.385-394
• /
• 2002

This study was constructed the correlations of the embryonic developmental rates and the frequency of chromosome aberration using ear-skin-fibroblast cell in nuclear transfer (NT) derived embryos. Karyoplast-oocyte complexes were fused and activated simultaneously, then cultured for seven days to assess development. The developmental rates of NT and in vitro fertilization (IVF) embryos were 55.4% vs 63.5%, 31.7% vs 33% and 13.4% vs 16.8% in 2 cell, 8 cell and blastocyst, respectively. Firstly, the frequency of chromosome aberrations were evaluated using fluorescent in situ hybridization (FISH) technique with porcine chromosome 1 submetacentric specific probe. Chromosome aberration was detected at day 3 on the embryo culture, the percentages of chromosomal aneuploidy in NT and IVF embryos at 4-cell stage were 40%, 31.3%, respectively. Secondly, embryonic fragmentation was evaluated at 4-cell stage embryo. Frequency of embryonic fragmentations was in 51.3% of NT, 61.3% of IVF, 28.9% of parthenogenetic activation at 4-cell stage. The proportion of fragmentation in NT embryos was higher than activation embryos. This result indicates that chromosomal abnormalities and embryonic fragments are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT related with lower implantation rate, increased abortion rate and production of abnormal fetuses.

• Applied Microscopy
• /
• 제21권1호
• /
• pp.63-76
• /
• 1991

Butylated hrdroxyanisole(BHA), a widely used food additive phenolic antioxidant, is known to inhibit cancer formations inducible with a wide variety of chemical carcinogens including aflatoxin $B_1(AFB_1)$. Thus, in the present study morphological characteristics underlying the hepatoprotective effects of BHA against $AFB_1$ inducible ultrastructural changes of hepatocytes have been examined. The obtained results are as follows : 1 . Livers obtained from rats treated with $AFB_1$ in vivo have been examined with transmission electron microscope. Among the many hepatocellular structural aberrations induced by $AFB_1$ treatment, the nuclear chromatins were found to be distributed irregularly('cap formation') and the nuclear membrane was found to be partially segregated. Furthermore, there were many lipid droplets, hyperplasia of smooth endoplasmic reticulum, dialated rough endoplasmic reticulum and, lysosomes arrested at various stages of its development. 2. Also, when $AFB_1$ was given in vitro to hepatocytes which have been isolated from untreated normal rats and examined under scanning electron microscope, there were much 'blobbing' phenomena resulting from cytoskeletal disturbances. 3. However, in the liver obtained from rats pretreated with BHA and then give the $AFB_1$, the observed morphological aberrations were in much reduced extent. Similarly, the BHA-hepatocytes had much decreased severity in the $AFB_1$ inducible blob formations.

• 대한미생물학회지
• /
• 제19권1호
• /
• pp.85-108
• /
• 1984

In order to study the relationship between resistance of tumor cells to anticancer drugs and immunologic cytotoxicity and their chromosome number, a line of cancer cells (NS-1) was exposed to BCNU and CCNU in vitro. Characteristics of the distribution of chromosome number of the survived cells were then comparatively analyzed. Effect of immune mediated cytotoxicity, i.e. complement and cell-mediated cytotoxicity, on the ploidy characteristics was observed in the same way. NS-1 cells were found to be a population of neoplastic cells of heterogeneity having 5 to 115 chromosomes per cell in metaphase. The majority of the cells were belong to the class of chromosome number 56 to 60 which were considered as the stem cell line. Dramatic changes in the distribution of chromosome number following drug treatment were not observed. However the range of chromosome distribution was slightly changed. Characteristics of chromosomal distribution of drug treated cells were not significantly varied by different doses of drug treated. Changed chromosomal distribution patterns of drug treated cells were reversible, especially the cells having 56 to 60 chromosomes recovered rapidly. Cells having 41-60 and 61-80 chromosomes among cells treated with BCNU and cells with 41-60 chromosomes after CCNU treatment were the major population which regenerated continuously. Following BCNU treatment cells having 61-80 chromosomes were not varied much whereas CCNU treatment affects the population in the same class. Chromosomal aberrations were significantly enhanced by BCNU and CCNU treatment. The frequency of chromosomal aberrations was greater in cells having more than 40 chromosomes compared with that in cells having less than 40 chromosomes. Changes in ploidy characteristics of the cells following complement mediated and cell mediated cytotoxicity were not significant. Therefore it was tentatively concluded that association of numerical distribution pattern of NS-1 cells with the response to the treatment used in this experiment was not recognized.

• Journal of the Optical Society of Korea
• /
• 제19권2호
• /
• pp.136-143
• /
• 2015

Image deblurring by a deconvolution method requires accurate knowledge of the blur kernel. Existing point spread function (PSF) models in the literature corresponding to lens aberrations and defocus are either parameterized and spatially invariant or spatially varying but discretely defined. In this paper, a parameterized model is developed and presented for a PSF which is spatially varying due to lens aberrations and defocus in an imaging system. The model is established from the Seidel third-order aberration coefficient and the Hu moment. A skew normal Gauss model is selected for parameterized PSF geometry structure. The accuracy of the model is demonstrated with simulations and measurements for a defocused infrared camera and a single spherical lens digital camera. Compared with optical software Code V, the visual results of two optical systems validate our analysis and proposed method in size, shape and direction. Quantitative evaluation results reveal the excellent accuracy of the blur kernel model.

• 한국광학회지
• /
• 제4권1호
• /
• pp.28-35
• /
• 1993

수차가 정확히 알려지지 않은 결상계에 있어서, exit pupil에 인위적인 위상의 random fluctuation을 도입하고 북스펙트럼 스펙클 영상법(bispectral speckle imaging)을 이용하므로서 수차의 효과를 극소화하여 거의 회절한계의 영상을 얻을 수 있다. Defocus, 구면수차, 코마수차, 비점수차가 각각 1파장씩 있을 때, 주어진 사용영상수(50개)에 대해서 Gaussian random phase model의 correlation length가 어느 정도일 때 최적의 결과를 얻을 수 있는지를 점 물체에 대해 컴퓨터 시뮬레이션을 시행하므로서 연구하였다. 평가기준으로서는 복원된 점물체에 대한 point spread function의 FWHM, normalized peak intensity, MTF 그리고 visual inspection을 채용하였는데, exit pupil 위에서 Fried parameter ${\Upsilon}_0$ 범위에 대한 수차의 차의 rms값 $\sigma$가 구면수차에 대해서는 0.27~0.53 파장일 때, defocus와 비점수차에 대해서는 0.24~0.36 파장일 때, 좋은 결과를 주는 것으로 나타났고, 코마수차의 경우에는 좋은 결과를 얻을 수 없었다.