• Applied Microscopy
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• 제25권1호
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• pp.30-47
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• 1995

The ultrastructural changes of adrenal chromaffin cells and ganglion cells in the adrenal gland of vacor-induced diabetic Mongolian gerbils were studied by electron microscopy. After one month of vacor-induced diabetes, some chromaffin cells were filled with dense bodies and large cytosomes with formy contents. Most of degenerating axon terminals were observed on chromaffin cells. A few macrophages were found among chromaffin cells at one month after induction. Several of these macrophages were filled with numerous phagosomes. After one month of vacor-induced diabetes, the ganglion cells showed increase in numbers of dense bodies and degenerating dendrites compared with the normal ganglion cells. Both electron dense and lucent types of degenerating axon terminals were found in interstitial space of the ganglion cells. Degenerating unmyelinated and myelinted axons contained dense and lamellar bodies. The satellite cells and macrophages with engulfed degenerated axon terminals were observed. After three months of vacor-induced diabetes, the unmyelinated and myelinated axons showed degenerative changes, whereas no structural changes could be demonstrated in adrenal ganglion and chromaffin cells. The satellite cells and macrophages containing partially digested debris were still commonly observed in the interstitial space of adrenal medulla. These results suggest that the degenerative changes occur in the adrenal ganglion cells as well as adrenal chromaffin cells of vacor-induced diabetic Mongolian gerbils.

• 한국식품과학회지
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• 제14권1호
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• pp.30-35
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• 1982

육(肉)의 가열시(加熱時) 육조직내(肉組織內)에 어떤 변화가 일어나는지를 관찰하기 위하여 우육(牛肉)을 $80^{\circ}C$로 가열(加熱)한후 scanning 및 transmission 전자현미경으로 육(肉)의 endomysial connective tissue, sarcolemma, transverse fidge, Z-disc, A 및 I-band등(等)을 관찰한바 $80^{\circ}C$에의 가열(加熱)로 endomysium, sarcolemma 등(等)이 응고됨과 아울러 심한 파괴현상을 보였으며 근원섬유 구조에 있어서도 I-band가 심한 절단현상을 보임과 아울러 A-band에 있어서는 심한 응고현상이 관찰되었으나 Z-disc는 비교적 열(熱)에 잘 견디는 것으로 관찰되었다.

• 한국발생생물학회지:발생과생식
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• 제2권2호
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• pp.157-163
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• 1998

흰쥐의 배아발생 동안에 피질반응 후 배아 외부에 새롭게 형성된 피질과립막 (cortical granule envelope, CGE)이 존속하는지 여부와 투명대와 배아표면의 미세구조 변화를 조사하였다. 흰쥐배아의 투명대와 배아표면의 미세구조는 주사전자현미경으로 관찰하였으며, 피질과립막 형성과 분포는 Ulex europaeus agglutinin I lectin을 표지하여 형광현미경으로 관찰하였다. 배아표면은 미수정란 과는 다르게 배아표면의 미세융모가 단축된 특징을 보였고, 8-세포기 배아에서 뚜렷하게 볼 수 있는 CGE에 의해 덮여 있다. 투명대의 구조 역시 미수정난자에 존재하는 구조와는 다른 특징을 나타냈고, 특히 투명대의 섬유성 미세공 구조가 거칠어지고 수적인 감소가 나타났다. 위란강에 피질반응에 의한 피질과립막이 형성되어 배아발생 동안에 존속하였으나 수정란보다는 엷고 국소적인 분포양상을 나타내었다. 본 연구 결과를 종합해 볼 때 흰쥐 초기 배아 발생 동안에는 배아 외부에 피질과립막이 존속하고, 수정시에는 투명대 경화 뿐만 아니라 피질반응에 의해 투명대의 미세구조와 배아표면의 구조도 변화됨을 알 수 있다.

• Journal of Plant Biology
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• 제34권3호
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• pp.201-213
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• 1991

This study has been carried out to investigate the ultrastructural changes, formation of storage materials in endosperm cells with electron microscope during the seed formation of Panax ginseng C.A. Meyer. In the early stage of seed formation with green seed coat, the endosperm was cellular type. Cell plate was largely composed of dictyosome vesicles in early stage of wall formation after mitosis. Central vacuole was gradually subdivided into several small-sized vacuoles. During the differentiation of plastids, some proplastid was replaced by amyloplast with starch grains and lamellar structure. A number of mitochondria with well developed cristae were distributed in cytoplasm. Rough endoplasmc reticulum, dictyosome, microbody, free ribosomes and polysomes were evenly distributed in cytoplasm. Spherical spherosomes were formed from dictyosome containing the lipid materials of even electron density. Protein bodies were formed by interfusing between vacuoles and vesicles derived from rough endoplasmic reticulum which contained the amorphous protein of high electron density.

• Parasites, Hosts and Diseases
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• 제49권1호
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• pp.25-31
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• 2011

Cryptosporidium parvum is known as one of the most highly resistant parasites to gamma irradiation. To morphologically have an insight on the radioresistance of this parasite, ultrastructural changes in C. parvum sporozoites were observed after gamma irradiation using various doses (1, 5, 10, and 25 kGy) following a range of post-irradiation incubation times (10 kGy for 6, 12, 24, 48, 72, and 96 hr). The ultrastructures of C. parvum oocysts changed remarkably after a 10-kGy irradiation. Nuclear membrane changes and degranulation of dense granules were observed with high doses over 10 kGy, and morphological changes in micronemes and rhoptries were observed with very high doses over 25 kGy. Oocyst walls were not affected by irradiation, whereas the internal structures of sporozoites degenerated completely 96 hr post-irradiation using a dose of 10 kGy. From this study, morphological evidence of radioresistance of C. parvum has been supplemented.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2000년도 공동 춘계학술대회
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• pp.72.1-72
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• 2000

No Abstract, See Full Text

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2000년도 추계 학술발표회
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• pp.64.2-64
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• 2000

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.55-60
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• 2016

The aim of the present study is to determine the characteristics of genotype and phenotype of Echinococcus granulosus derived from wild sheep and to compare them with the strains of E. granulosus sensu stricto (sheep-dog) and E. granulosus camel strain (camel-dog) in Iran. In Khojir National Park, near Tehran, Iran, a fertile hydatid cyst was recently found in the liver of a dead wild sheep (Ovis orientalis). The number of protoscolices (n=6,000) proved enough for an experimental infection in a dog. The characteristics of large and small hooks of metacestode were statistically determined as the sensu stricto strain but not the camel strain (P=0.5). To determine E. granulosus genotype, 20 adult worms of this type were collected from the infected dog. The second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA (rDNA) and cytochrome c oxidase 1 subunit (COX1) of the mitochondrial DNA were amplified from individual adult worm by PCR. Subsequently, the PCR product was sequenced by Sanger method. The lengths of ITS2 and COX1 sequences were 378 and 857 bp, respectively, for all the sequenced samples. The amplified DNA sequences from both ribosomal and mitochondrial genes were highly similar (99% and 98%, respectively) to that of the ovine strain in the GenBank database. The results of the present study indicate that the morpho-molecular features and characteristics of E. granulosus in the Iranian wild sheep are the same as those of the sheep-dog E. granulosus sensu stricto strain.

• Applied Microscopy
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• 제23권1호
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• pp.139-163
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• 1993

Background: It has been well established and is now no longer a controversial issue that ischemia produces a series of inflammatory reactions and the ischemic myocardium cannot survive without adequate restoration of coronary flow, ie, reperfusion. Nevertheless, controversies that intravascular pluggings (IVP) by polymorphonuclear leukocytes (PMNs) or platelets may cause contractile dysfunction in ischemia and even in repefusion still remain. Accordingly, we attempted to examine the intravascular plug fomation as well as the ultrastructural changes in myocytes and microvessels and to determine the relation among them. Methods: 1) Human (n= 10, 39-63 years of age; 3 females and 7 males): left ventricular myocardium (LVM) was biopsied from chronic ischemic heart disease patient during bypass surgery. 2) Calf (Holstein-Friesian species, n=4): Circumflex branch of the left coronary artery (LCx) was occluded (ischemia) for 45 minutes and recanalized (reperfusion) for 3 and 6 hours, respectively and LVMs were biopsied after occlusion and recanalization, respectiverly. 3) Rat (Sprague-Dawley species, n=20): Left coronary artery (LCA) was occluded for 20 minutes and recanalized for an hour as the method described by Selye et al., (1960) and hearts were removed after occlusion and recanalization, respectively. 4) Pig (landrace type, n=7): Anterior ascending branch of the left coronary artery (LAD) was coccluded for 45 minutes and recanalized for 2 hours and LVMs were biopsied after occlusion and recanalization, repectively. All of the LVMs were routinely prepared for transmissiom electron microscopy. Rseults: In human, most of the LVM showed irreversible ultrastructural changes in myocytes and frequent IVPs by PMNs or platelets without any significant correlation with age or sex. In the animal LVM, myocytes showed reversible ultrastructural changes with slight variations in accordance with the species, duration of ischemia and reperfusion or site of biopsy, however, injuries were more severe in the subendocardial myocytes and IVPs by PMNs or platelets were frequently observed. Ultrastructural changes in the myocytes seemed to be gradually improved by recanalization, howerver, IVPs were still observed after recanalization. Conclusion: These results suggest that microvessels are more resistant to ischemic insult than the myocytes themselves and IVP by PMNs and platelets may play an important role to produce ischemic or reperfusion injuries. Thus, it is favorable that angioplasty is preceded by thrombolysis and it is likely that restoration of myocardial function requires relarively long period of time even after recanalization.

• 한국가축번식학회지
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• 제19권2호
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• pp.105-117
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• 1995

This study was carried out to investigate the histomorphological changes and the electrophoretic patterns of egg components, obtained from 100 of 1-year-old female catfish(Silurus asotus). Especially, the light microscopic and ultrastructural changes of ooplasm and follicular membranes of oocytes, were observed by light and transmission electron microscope. All data were collected from October in 1992 to May in 1993. The size of the nucleoli and number of the yolk granules increased as the oocyte grew. Yolk granules were deposited in the oocyte as fluid. Due to the presence of large early and late maturing oocytes, their ovaries were large, transparent, granular, and greenish in color. As the percentages of fish in LMO and RO stage increased from March to April, mean of GSI values(19.95%) increased. Follicle cells such as granulosa cell and thecal cell change a squamous into cuboid shape in LPO and EMO stage. Processes, microvilli, from the granulosa cells and from the oocyte grow and make contact with each other in the pore canals of the zona radiata during vitellogenesis, but are withdrawn as the zona radiate becomes more compact and devoid of pore canals during oocyte maturation. The electrophoretic pattern of major band in mature stage was much thicker(21k, 24k, 32k, 45k, 67∼110k, 170k dalton) than that in previtellogenic phase.