• Toxicological Research
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• 제17권1호
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• pp.33-39
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• 2001

To evaluate the skin toxicity oj topical toluene application, toluene (35 mg/$cm^2$) was sequentially applied to the portion rat skin for five days. The topical toluene application resulted in increased xanthine oxidase activity and CYP content, and significantly decreased superoxide dismutase and glutathione peroxidase activities at five days in rat skin. Especially catalase activity was remarkably decreased in toluene-applied rat skin. And benzylalcohol dehydrogenase activity showed also a significant decrease in toluene-applied skin. On the other hand, histopathological ultrastructural examination revealed disrupted epidermal basement membrane, rared intercellular adhensions and degenerated keratin layer due to topical toluene application. Increased deposit of cerrous perhydroxide resulted from reaction with $H_2O_2$was abserved in toluene-treated animals. These results indicate that oxygen free radical may be responsible for ultrastructural changes in skin tissue by toluene application to rat skin.

• Journal of Microbiology
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• 제34권3호
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• pp.220-224
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• 1996

Ultrastructural organization of encysting zoospores of Allomyces macrogynus was examined using the methods of cryofixation and freeze substitution. During enxcystment, obvious changes were observed at the surface of the plasma membrane and in the structure of gamma particles. Many multivesicular bodies associated with the plasma membrane were observed at early stages of encystment. After induction of encystment, vesicles were found within the gamma particles. These vesicles appeared to leave gamma particles after forming multivesicular bodies. This study suggests that the cell wall formation during encystment is mediated by the fusion of multivesicular bodies with the plasma membrane.

• International Journal of Industrial Entomology and Biomaterials
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• 제21권1호
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• pp.117-125
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• 2010

The tropical tasar silkworms, Antheraea mylitta (D) produce famous silk 'Kosa' in central part of India. Due to outdoor rearing it became susceptible to viral infection including cytoplasmic polyhedrosis virus (CPV). The common mode of entry of cytoplasmic polyhedrosis virus is per os and cause gresserie disease to the larvae. Histopathological studies elucidated the insect CPV virus produces infective polyhedral inclusion bodies (PIBs) in the midgut cell cytoplasm of virus infected fifth instar larvae. The PIBs multiply enormously in the cytoplasm without invading the nucleus. Ultrastructural studies confirmed the pathological effects of CPV on in midgut cell cytoplasm. The multiplication of polyhedral inclusion bodies took place into the vacuoles and form virogenic stromata in the cytoplasm of cells. However, the encapsulations of polyhedral inclusion bodies into the polyhedrin protein occurred and polyhedra were released into the lumen. At the late stage of infection, cells showed the regressed cytoplasmic organelles with large vacuoles and elongated mitochondria. Hence, the horizontal transmission of CPV causing the midgut cells disintegration in the tasar silkworm, Antheraea mylitta (D) confirmed during infection.

• Applied Microscopy
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• 제28권1호
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• pp.21-38
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• 1998

The present study was performed to determine the effect of cold stress on myocardium of aging rat. Control groups, which aged 6, 12 and 24 months, were compared with age-matched experimental groups that were exposed to moderate cold stress for a hours daily in a week at laboratory cold room $(4{\pm}1^{\circ}C)$. The histological, histochemical and ultrastructural changes of myocardium were observed. The results were summarized as follow: 1. Age-dependent histological change of control groups was observed the formation of contraction band in 24months aged group. The experimental groups submitted to cold stress showed a similar change pattern as seen in control groups. However, the degree of change in the experimental groups was significantly larger than that of control groups. In the 34 months aged group the formation of hypercontraction band was observed. 2. Regarding age-dependent histochemical changes of control groups, we observed the increase activities of PAS and Masson's trichrome. In experimental groups the activities of PAS and Masson's trichrome were also increased with age. Compare with control group, the activities of PAS was increased but the activities of Masson's trichrome was decreased. 3. Age-dependent ultrastructural changes on vacuolization, lysosome were observed. In control groups the structural changes occur at 12 months. The accumulation of lipofuscin, contraction band, hypercontraction band and a component of connective tissue were observed in 24 months. However, the degree of change in the experimental groups was significantly larger than that of control groups. In contract, the myelin body in intercalated discs was observed in 24 months of experimental groups.

• Parasites, Hosts and Diseases
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• 제25권2호
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• pp.99-109
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• 1987

The present study was carried out to examine the effect of a calcinogen, aflatoxin B1 on the ultrastructural changes of ciliary epithelial cells in mice infected with Clonerchis sinensis. A total of 93 male albino mice(BALB/c strain) was divided into 3 groups; group I, treated with 1.0 ppm aflatoxin Bl for 12 weeks; group II, given 50 C. sinensis n;etacercariae, and group III, given 50 metacercariae and treated with 1.0 ppm aflatoxin Bl for 12 weeks. Three mice served for untreated-uninfected controls. From 4 weeks after the treatsment and/or in(ection, three mice from each group were sacrificed at 4 week intervals up to the 40th week, and their hepatobiliary tissues were prepared for transmission electron microscopy. The most prominent ultrastructural changes in group I were remarkable enlargement of nuclear size, separation of nucleolus, dispersed chromatin granules in nuclei and increased dense granules along the inner membrane of nuclei. In the cytoplasm there was slight proliferation of mitochondria and endoplasmic reticulum (ER) at earlier stage. At the 12th week separation of fibrillar and granular components of the nucleolus was a characteristic finding. As the time elapsed, epithelial cells showed fiattened-cuboidal form and a tendency of atrophy. Most of the nuclei were elongated and polygonal in shape. In group II the appearance of elaborate interwoven folds of lateral cytoplasm forming a labyrinth of interconnected intercellular space and variety in nuclear shape were the prominent fadings at earlier stage. The cytoplasm showed slight proliferation and dilatation of mitochondria and ER, and a small number of mucin droplets. In the basement membrane scanty fibrous cells were seen. With time, variety in nuclear shape, marked proliferation and dilatation of rough ER and some collagen fibrils were demonstrated. Other features of intracellular organelles and mucin droplets persisted. In group III cuboidal epithelial cells showed their remarkably enlarged and irregular nuclei, increased chromatin granules in the nuclei, separated nucleoli, proliferated and dilated rough ER. With time, sequestered mitochondria showed blob-like evaginations which lacked cristae and dense matrix, and were limited by a single membrane. Since the 20th week, microvilli were relatively scanty and poorly developed. Organelles and inclusions in the cytoplasm of metaplastic cells were poor. Nuclei were variable in shape. The nlost prominent changes at later stage were separation of nuclei from the cytoplasm, and appearance of numerous and irregularly angled electron dense granules in the nuclei.

• Journal of Nutrition and Health
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• 제25권6호
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• pp.501-510
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• 1992

식이중에 첨가된 coenzyme ${Q}_{10}이 ADR을 투여한 흰쥐의 심근미세구조 변화에 미치는 영향을 검토하기 위하여 ADR 2수준(1.0 및 2.0mg/kg B.W/week)과 coenzyne ${Q}_{10} 3수준(0, 0.1및 0.5g/kg diet)에 의한 6개의 실험군과 basal diet만을 공급하는 대조군을 설정하여 8주간 실험동물을 사육하였다. 체중증가량은 ADR의 투여수준이 높을수록 유의적으로 감소되었으나 coenzyme ${Q}_{10}급여에 의한 회복효과는 나타나지 않았다. 전자현미경을 통한 관찰결과, ADR투여는 심근세포내 미세구조의 변성을 유도함이 확인 되었고 특히 mitochondria를 비롯한 세포기관의 소실 및 파괴를 관찰할 수 있었으나 coenzyne ${Q}_{10}을 미리 급여한 군에서는 그정도가 완화되었다.

• 한국동물학회지
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• 제16권1호
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• pp.43-53
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• 1973

年齡에 따른 미토콘드리아의 構造的變化를 調査하기 위하여 電子顯微鏡을 利用하여 배추흰나비, Pieris rapae L.의 飛筋을 觀察하였다. 미토콘드리아는 크리스타가 잘 발달되지 않은 A型과 크리스타가 복잡하게 발달된 B型의 두種類가 存在하였다. 羽化直後의 것에서는 A型과 B型미토콘드리아가 꼭같이 存在하였고 羽化後 10日 經過한 것에서는 B型미토콘드리아에 比하여 A型이 急速히 減少하였다. 羽化後 10日이 經過된 것의 筋細胞에서는 B型미토콘드리아가 年齡의 增加에 따른 微細構造的變化를 이르켰다. 이러한 老衰된 미토콘드리아의 微細構造的 變化像은 部分的으로 그 內膜이 髓　狀構造를 再形成하는 것으로 나타났는데 이것은 곧 年齡에 따른 退化를 意味한다. 髓　狀構造를 形成하는 것은 많은 同心圓體이며 이 同心圓體의 數와 크기는 年齡과 比例하면서 增加했다. 筋細胞의 細胞質에서 미토콘드리아 內로 侵入한 글리코겐 粒子는 同心圓體의 中央에서도 觀察되었다.

• Applied Microscopy
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• 제51권
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• pp.20.1-20.12
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• 2021

We explored the link between mitochondrial biogenesis and mitochondrial morphology using transmission electron microscopy (TEM) in lymphoblasts of pediatric acute lymphoblastic leukemia (ALL) patients and compared these characteristics between tumors and control samples. Gene expression of mitochondrial biogenesis markers was analysed in 23 ALL patients and 18 controls and TEM for morphology analysis was done in 15 ALL patients and 9 healthy controls. The area occupied by mitochondria per cell and the cristae cross-sectional area was observed to be significantly higher in patients than in controls (p-value=0.0468 and p-value<0.0001, respectively). The mtDNA copy numbers, TFAM, POLG, and c-myc gene expression were significantly higher in ALL patients than controls (all p-values<0.01). Gene Expression of PGC-1α was higher in tumor samples. The analysis of the correlation between PGC-1α expression and morphology parameters i.e., both M/C ratio and cristae cross-sectional area revealed a positive trend (r=0.3, p=0.1). The increased area occupied by mitochondria and increased cristae area support the occurrence of cristae remodelling in ALL. These changes might reflect alterations in cristae dynamics to support the metabolic state of the cells by forming a more condensed network. Ultrastructural imaging can be useful for affirming changes occurring at a subcellular organellar level.

• Applied Microscopy
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• 제25권4호
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• pp.26-51
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• 1995

The present study was designed to examine effect of long term weight-training on aging atrophy in the rat skeletal muscle. Male rats of 8, 15, and 24 month old were used. Each age groups included control and weight-training for 5 months by using body press apparatus. The histo- and cytochemical, ultrastructural and stereological changes in aging skeletal muscles of the rat were observed in the present study. During the training period the body weight and muscular weight in all groups except the rectus femoris and the gastrocnemius in young age groups remained constant, but muscular weights were increased in the rectus femoris and the gastrocnemius muscles in young age groups. In trained rat, the volume density of muscle fiber type IIA and IIB were increased, but those of type IIC was decreased. Type I remained constant in 8 and 15 month old age groups, but reduced in the tibialis anterior and the gastrocnemius muscles in the 24 month old groups. Some histotological and ultrastructural changes associated with age were found: numerical increase of cytiplasmic vacuoles, lysosomes, lipofuscins, and irregularity of myofibrils. At 24 month old groups some unusual formation of contraction band and muscle splitting were observed. After weight-training, ultrastructural degenerative changes occured in the type I muscle fiber, such as splitting of muscle fiber, disorganization of myofilaments, swelling of mitochondria, accumulation of many lipid droplets, appearance of many lysosomes and residual bodies and necrotic fibers, in the old age groups. But, in the type II muscle fibers hypertrophy of muscle fiber appeared without any noticible damage as the type I. The activities of $Mg^{++}$ -ATPase decreased with age and this enzyme activities in the trained rat were significantly decreased with age. Activities of the acid phosphatase were increased with age and significantly in the trained rat. In stereological analysis, volume density of the myofibrils and the tubular system were increased, on the other hand there mitochondrial capacity was decreased. These experimental results suggested that old rats are not susceptible to be affected by weight-training as young rats, and that physical capacity of the rats must be considered when old rats are exercised for training.

• Journal of Korean Neurosurgical Society
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• 제29권5호
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• pp.599-603
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• 2000

Objectives : In lumbar spine surgery it is observed that the ligamentum flavum(LF) is bilayered, and the inner layers can be left in situ to prevent peridural adhesion in open lumbar disc surgeries. The purposes of this study are to investigate ultrastructural differences between the inner and outer layer of lumbar LF by electron microscopic examination, and to see whether these differences are, if present, more prominent in chronic degenerative lumbar spinal disorders as compared with acute lumbar disc diseases. Methods : Biopsy specimens of LF were obtained from nine patients undergoing lumbar spine surgery, five of them for degenerative spinal stenosis and four for acute disc herniation. During the surgery the outer layers of LF were carefully dissected from the inner layer, and four pieces($1{\times}1{\times}1-mm$) of biopsy samples were made from each layer. These were examined with electron microscope for the morphologies and the contents of the elastic and the collagen fibers. Results : The outer layer of LF showed elastic fiber degeneration as evidenced and decreased fiber content, while the inner layer was relatively preserved in both cases of degenerative spinal stenosis and acute disc herniation. The ultrastructural changes of the layers were more evident in the outer layer. Conclusion : With these observations the authors believe that the LF degeneration may occur mainly in the outer layer, and that this fact may aid in making the rationale for using the inner layer as physiologic barrier to prevent peridural adhesion in open lumbar disc surgeries.