• 한국연초학회지
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• 제17권1호
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• pp.33-40
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• 1995

Structures of the adventitious root meristem induced from callus culture of tobaco (Nicotiana tabacum cv. NC 82) leaves were investigated by light and transmission electron microscopy. Structural differences between in vitro root and callus cells were also examined by the microscopy. The submicroscopic features of the in vitro root cells were as follows. Intercellular spaces were not developed and nuclei with two nucleoli were observed occasionally. Plasmodesmate were found in groups or sing1y on transverse and longitudinal walls. Amyloplast solely filled with starch grains, with one to five electron - dense bands, was surrounded by single membrane. in the callus cells, vacuolization of central part in the cytoplasm having mitochondria with swollen cristae and starch grains like those of in vitro root cells was a distinct feature. Vesicles which were found between cell wall and plasma membrane may be arisen by a process of protoplasmic invagination. By comparing of ultrastructures between the cells of callus and in vitro roots we found that the distinct differences lied on thickened cell walls and hypertrophed vacuoles in the former, and less thickened cell walls and several small vacuoles in the later.

• 한국미생물·생명공학회지
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• 제5권4호
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• pp.185-189
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• 1977

성숙자계에 과양의 vitamin A, D 및 E를 투여하고 신근위파세요관상피세포에 야기되는 징세구조의 변화를 관찰한바 그 결과를 요약하면 다음과 같다. 1일 2.5ml의 기준량을 투여한 군에서는 mitochondria의 경한 여진 및 rER에서 ribosome의 경광의 탈낙이 있으며, 7.5ml 투여군에서는 세포의 종완이 좀더 심해저서 기질이 넓어져 보였고 mitochondria는 중등도의 여창을, 곳에 따라서는 서로 융합한 chondriosphere의 형성도 볼수 있었다. 12.5ml 투여군에세는 상기한 소견들이 더욱 심하여지는 경향이였다. 이상의 연구결과로보아 vitamin 과양투여에 의한 순근위암세요관상피세포의 변화는 세포고복을 주로하는 경징한 가역적변화로서 성계에 대한 vitamin 과양투여는 신근위곡세요관상피세포에 큰 영향을 주지 않는것으로 사요된다.

• 한국어병학회지
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• 제5권2호
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• pp.61-75
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• 1992

틸라피아에 실험적으로 Edwardsiella tarda를 경구감염 시켰다. 틸라피아의 장을 자극시키지 않았을 때는 E. tarda가 감염되지 않았으나 과산화수소로 장을 자극시킨후 E. tarda를 투여하였더니 감염되었다. 150~200g되는 틸라피아 한마리에 $10^6CFU/m{\ell}$, $10^7CFU/m{\ell}$, $10^8CFU/m{\ell}$를 투여한 4일 후부터 죽은 실험어의 간장, 신장, 비장에 농창이 형성되었다. 또한 장관 장해부에서 세균이 증식되어 전신감염으로 급히 발병되어 죽은 예가 많았다. 자연감염어에서 볼 수 있는 증상이 나타났다.

• Applied Microscopy
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• 제24권2호
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• pp.12-25
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• 1994

This research was undertaken to determine the effects of the anticancer and immunosuppressive drug cyclophosphamide (CP) on the epididymis of the male rat in terms of ultrastructural alteration and protein analysis by SDS-PAGE at different groups; control group, 1 week group, 3 weeks group, 5 weeks group were treated with saline (control group) or CP at doses of 20mg/Kg/week, 1 time a week, respectively. In the cytoplasm of the principal cells on the epididymis, the mitochondrial outer and inner membranes were significantly swollen or disrupted. The cisterns of rough endoplasmic reticulum (rER) were also swollen, and a number of Golgi vesicles were increased, respectively. It is suggested that treatment with CP alters the specific cell organelles in all segments of the epididymis. CP caused changes in protein concentrations in cauda of epididymis after CP treatment. Total proteins of 30 to 39 species such as lactate dehydrogenase, carnitine acetyltransferase and acid phosphatase were expressed in the cauda fluid. Then the more CP was increased, the more concentration of proteins caused to decrease, synthesize or increase in epididymal cauda. In contrast to the control group, in particular 29KD and the other 10 proteins in the cauda fluid were decreased or disappeared, respectively, whereas 89KD and the other 6 proteins in the cauda, were increased or synthesized, respectively. The other proteins are not showed distinctive difference. Therefore, it is possible that CP at a high dose accumulation alters epididymal function with dose-related increase or decrease in specific activity of marked proteins for all regions of the epididymis (particularly, specific segment of cauda). These alterations could be mediated by direct, toxic effects of the drug on the epithelium or be secondary to changes in the spermatozoa as a result of the CP treatment.

• Applied Microscopy
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• 제22권1호
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• pp.89-102
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• 1992

This research was undertaken to determine the effects of the anticancer and immunosuppressive drug cyclophosphamide (CP) on the epididymal caput of the male rat in terms of ultrastructural alteration and protein analysis by SDS-PAGE at different groups; control group, 1 week group, 3 weeks group, 5 weeks group were treated with saline (control group) or CP at doses of 20 mg/kg/week, 1 time a week, respectively. In the cytoplasm of the principal cells on the epididymis, the mitochondrial outer and inner membranes were significantly swollen or disrupted. The lumens of rough endoplasmic reticulum (rER) were also swollen, and the number of Golgi vesicles were increased, respectively. It is suggested that treatment with CP alters the specific cell organelles in the epididymis. CP caused changes in protein concentrations in caput of epididymis after CP treatment. Total proteins of 32 to 37 species such as lactate dehydrogenase, carnitine acetyltransferase and succinate dehydrogenase were expressed in the caput fluid. Then the more CP was increased, the more concentration of proteins caused to decrease, synthesize or increase in epididymis. In contrast to the control group, in particular carnitine acetyltransferase and the other 9 proteins in the caput fluid were decreased or disappeared, respectively, whereas lactate dehydrogenase and the other 5 proteins in the caput fluid were increased or synthesized, respectively. The other proteins are not showed distinctive difference. These alterations could be direct mediated by toxic effects of the drug on the epithelium or be secondary to changes in the spermatozoa as a result of the CP treatment.

• The Plant Pathology Journal
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• 제32권2호
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• pp.85-94
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• 2016

Studies were conducted to determine the role of 3-methylthioproprionic acid (MTPA) in the pathogenicity of potato stem canker, Rhizoctonia solani, and the concentrations required to inhibit growth of R. solani under laboratory and plant house-based conditions. The experiments were laid out in a completely randomized design with five treatments and five replications. The treatments were 0, 1, 2, 4, and 8 mM concentrations of MTPA. The purified toxin exhibited maximal activity at pH 2.5 and $30^{\circ}C$. MTPA at 1, 2, 4, and 8 mM levels reduced plant height, chlorophyll content, haulm fresh weight, number of stolons, canopy development, and tuber weight of potato plants, as compared to the control. MTPA significantly affected mycelial growth with 8 mM causing the highest infection. The potato seedlings treated with MTPA concentrations of 1.0-8.0 mM induced necrosis of up to 80% of root system area. Cankers were resulted from the injection of potato seedling stems with 8.0 mM MTPA. The results showed the disappearance of cell membrane, rough mitochondrial and cell walls, change of the shape of chloroplasts, and swollen endoplasmic reticulum. Seventy-six (76) hours after toxin treatment, cell contents were completely broken, cytoplasm dissolved, and more chromatin were seen in the nucleus. The results suggested that high levels of the toxin concentration caused cell membrane and cytoplasm fracture. The integrity of cellular structure was destroyed by the phytotoxin. The concentrations of the phytotoxin were significantly correlated with pathogenicity and caused damage to the cell membrane of potato stem base tissue.

• 한국발생생물학회지:발생과생식
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• 제23권2호
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• pp.139-148
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• 2019

Rising of water temperature due to global warming is a great concern to aquaculturists and fishery biologists. Hence, the present study aimed to investigate the effects of high water temperature on juvenile red spotted grouper, Epinephelus akaara based on the evaluation of stress responses in blood. E. akaara juveniles were exposed to different thermal conditions ($25^{\circ}C$, $28^{\circ}C$, $31^{\circ}C$, and $34^{\circ}C$) for 6 weeks following 2 weeks of acclimation at $25^{\circ}C$. Blood cell morphology and number were examined at three sampling points (2, 7, and 42 days) from a total of 180 fish. Major erythrocytic cellular abnormalities (ECA) observed in blood smears of thermally stressed groups ($31^{\circ}C$ and $34^{\circ}C$) after 6 weeks were echinocytes, teardrop-like cells, swollen cells and vacuolated cells. Both red and white blood cell number (RBC and WBC) were significantly (p<0.05) elevated in $31^{\circ}C$ and $34^{\circ}C$ group after 6 weeks thermal exposure. Differential leucocytes number showed significant increases in neutrophil (N) and decreases in lymphocytes (L) in the highest temperature ($34^{\circ}C$). Different N:L ratio was observed at different thermal conditions which can be used as a reliable alternative to measure stress response. Taken together, these results suggest that higher temperature ($31^{\circ}C$ and $34^{\circ}C$) can interfere the immune system of red spotted grouper by altering the blood cell morphology and number.

• Mycobiology
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• 제30권3호
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• pp.117-127
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• 2002

Cleistothecial development in Aspergillus nidulans(teleomorph, Emericella nidulans) was examined with the transmission electron microscopy. Cleistothecial initial was a small coiled lump of cells, ca. 6 ${\mu}m$ in diameter, which was consisted of a slightly swollen core with a short "tail" hypha. Initials were wrapped with a loose layer of hyphae. Core cells of cleistothecial initials were broad and multinucleated at first, then formed dikaryotic ascogenous cells, followed by post-meiotic tetra-nucleate or octa-nucleate protoasci and finally mature ascospores. Croziers were formed early during cleistothecium development. The peridial layer of mature cleistothecia was derived from the wrapping hyphae which originally invested the young cleistothecium. Completion of peridial layers development was associated with the depositing of a non-enzyme reactive material around peridial cells. $H\ddot{u}lle$ cell formation during the cleistothecial development appeared to be somewhat coordinated with the developmental stages of cleistothecium.

• Journal of the Korean Wood Science and Technology
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• 제35권2호
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• pp.16-22
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• 2007

The behavior of ramie fibers and some wood elements in the early stage of alkali swelling was examined. When the fibers were treated with alkali solution, they significantly shrank in length and swelled in wall thickness. Ramie fibers showed a shrinkage averaging 23% in length and a swelling averaging 92% in width in 100 seconds treating time. Dimensional changes showed different fashion in each element of woods. The tracheids of latewood especially in Pinus densiflora and Larix kaempferi woods swelled intensively and showed balloon swelling, but in the case of Cryptomeria japonica, it was hardly observed. The swelling morphology of libriform fibers was similar to that of tracheids. The walls of vessel elements and parenchyma cells also swelled considerably in thickness but, no balloon swelling was found in both elements. The differences of swelling in different elements can be interpreted in terms of the differences of organization and/or chemical components of the cell walls.

• Journal of Plant Biotechnology
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• 제30권2호
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• pp.195-199
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• 2003

Extracts of Escherichia coli as a elicit were treated to suspension cultures of Streptanthus tostus in order to observe the effect on the pholem development. By the elicit treatment, cell wall, sieve endoplasmic reticulum (SER) and p-protein were normally synthesized, but the structure of amyloplast was changed from a round form to irregular and swollen unhalthy form with a tiny starch granular. Oil drops were new synthesized and accumulated in a large oleoplast and proteins were also accumulated in a single membrane. The concentration of sucrose in the phloem, which was induced during the elicit treatment, was higher than normally developed phloem cells. These results suggest that phloem cells might be changed in the normal cycles of metabolism of lipids, carbohydrates and proteins to overcome during the eilicit stress.