• Journal of the Korean Society for Aviation and Aeronautics
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• v.20 no.3
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• pp.63-67
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• 2012

Spaceflight induces a number of cardiovascular physiological alterations. To study adaptations to microgravity on Earth, the tail-suspended, hindlimb-unloaded rat model has been used to simulate the effects of microgravity. Despite the extensive use of this model to infer physiological adaptations of many organs to microgravity, little information has been obtained on the effect of tail suspension(TS) on cardiac adaptations in the rat. This study was aimed to investigate the effects of simulated microgravity on the rat myocardium using the TS model. Twenty-four male Sprague-Dawley rats were randomly assigned to 3 experimental groups(1, 7 and 14 days of TS) and a control group. A microscopic examination was performed to assess histopathological changes in the myocardial morphology. The hearts from the control group, the 1 day-TS rats and the 7 day-TS rats revealed no evident abnormalities in cardiomyocyte size and morphology. At day 14 of TS, in contrast, the ventricular cardiomyocytes appeared more separated from each other and were slightly smaller in size compared with those of the control group. Also seen were scattered areas exhibiting focal disorganization of muscle fibers and some degenerating cardiomyocytes, of which the nuclei had become pyknotic or disappeared. In this study, we demonstrated that the ventricular cardiomyocytes underwent degeneration and atrophy at the microscopic level during exposure to simulated microgravity in TS rats.

• Restorative Dentistry and Endodontics
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• v.4 no.1
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• pp.7-9
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• 1978

Brass specimen, copper based alloy was prepared in cubic form about $1cm{\times}1cm{\times}1cm$ in volume. The specimens were mechanically compressed in one direction until the dimension distorted to 20%, 40%, 60% and 80% in length. The compressed specimens with 80% distorted in length were then heat treated in $200^{\circ}C$, $300^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$ and $600^{\circ}C$ for 30 minutes. Microscopic examination was made on both compressed and heat treated specimens. The results obtained from the study were as follows: 1. Grain boundary and twin phenomenon was clearly seen in 0% and 20% compressed cases. Slip bands was appeared in 40% cases and distributed equally as well as twin. 2. The first evidence of slip bands was observed in 20% and the bands grew thicker and denser as the compression increased. 3. The density of the bands were reduced after annealing in $200^{\circ}C$ and completely disappeared at $300^{\circ}C$ cases. 4. Recrystallization was noticed unevenly in $300^{\circ}C$ cases and the evidence of twin was observed in these crystallized area. 5. In $400^{\circ}C$ cases the grain boundary was evenly found and the twin phenomenon was clearly observed. Grain boundary and twin was noticeably formed in size according to the annealing temperature increased.

• Journal of Chest Surgery
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• v.22 no.3
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• pp.373-383
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• 1989

Glutaraldehyde is known as an ideal preservatives for pericardial heterograft, and many laboratories used this chemicals for preparing tissue valves, pericardial patches and MVOP [monocusp ventricular outflow patch] so we tried to find out the appropriate concentration and ingredients of the Glutaraldehyde for the preparing bovine pericardium. We selected 50 calves, aged about 2 years, and procured their pericardia. These were divided 6 groups such as fresh group, treated with only antibiotics, treated with Glutaraldehyde 0,5%, 0.625 %, 0.75 %, and 0.875 %, and our experiments included microbial culture test, tensile strength measurement and microscopic examination. On microbial culture, there were no growth on 1 week and 4 weeks after preparation with all kind of Glutaraldehyde, but on 4 weeks after only antibiotics treatment [Penicillin, Streptomycin, Kanamycin, Amphotericin -B] E.coli and candida albicans were observed. On tensile strength test, 0.625 % and 0.75 % Glutaraldehyde were revealed as the best preservatives for bovine pericardium and compared to other commercial products they kept more desirable tensile strength. On light and electron microscopic examinations, Glutaraldehyde treated pericardia had much regular and compact collagen fibers and preserved more normal structures, but there were no difference between the different concentration of the Glutaraldehyde. We concluded that 0.625% and 0.75 % Glutaraldehyde were the best concentration for preservation of bovine pericardium in our experiment.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.113-116
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• 2019

Bovine theileriosis caused by Theileria sergenti is a tick-borne hematoprotozoan disease that is characterized by chronic anemia and fever in cattle. In this study, results of microscopic examination and PCR detection confirmed 17 Korean native cattle with emaciation and fever as acute bovine theileriosis caused by T. sergenti. Buparvaquone was injected as treatment, but was proved to be an inappropriate measure according to our study. After 6 months of injection, clinical signs and hematological values were recovered, but T. sergenti was still identified in blood sample as a result of microscopic exam and PCR. These results suggest that continuous management is necessary to control bovine theileriosis. Therefore, findings of this study may provide significant guideline on the control of bovine theileriosis.

• Korean Journal of Radiology
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• v.2 no.3
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• pp.159-163
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• 2001

Objective: The purpose of this study is to correlate the findings of peripheral hypoechoic rim, seen at transrectal ultrasonography (TRUS) in chronic prostatitis patients, with the histopthologic findings. Materials and Methods: Seven patients with pathologically proven chronic prostatitis were involved in this study. The conspicuity of the peripheral hypoechoic prostatic rim, seen at TRUS, was prominent and subtle, and to determine its histopathologic nature, the microscopic findings were reviewed. Results: In five of seven cases (71%), TRUS demonstrated a prominent peripheral hypoechoic rim. Microscopic examination revealed that inflammatory cell infiltration of prostatic glandular tissue was severe in three cases (42.9%), moderate in two (28.6%), and minimal in two (28.6%). In all seven cases, the common histopathologic findings of peripheral hypoechoic rim on TRUS were loose stromal tissues, few prostatic glands, and sparse infiltration by inflammatory cells. Conclusion: The peripheral hypoechoic rim accompanying prostatic inflammation and revealed by TRUS reflects a sparsity of prostate glandular tissue and is thought to be an area in which inflammatory cell infiltration is minimal.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.5
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• pp.396-405
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• 2001

Osseointegrated implants are used for the fixation of dental prosthesis with good long-term clinical results. In an attempt to improve the quantity and quality of the bone-implant interface, numerous implant modification have been used. Implants surface modifications have been used such as titanium-plasma sprayed, hydroxyapatite-coating, sandblasted, sandblasted and acid-etched, acid-etched. Rough surface implants have greater implant surface area and enhance the bone-implant interface and improve stabilization. The purpose of present study was to evaluate light microscopic and scanning microscopic examinations and removal torque value of newly developed calcium phosphate blast and acid-etched implant in the femur of rabbits. Titanium plasma sprayed(TPS) implant served as controls. After 12 weeks of healing of the femurs of 12 rabitts, the implant-containing segments of femur were removed on bloc and bone block including sections. Histologic examination and histomorphometric and removal torque values comparision were made for two implants. Obtained results are follows: 1. Newly developed calcium phosphate blasted and acid-etched implants were in close contact with bone under light microscopic examinations. 2. New implants showed mean bone-to implant contact 59.8%, whereas TPS implants showed mean bone-to implant contact 54.5% (statistically no difference p<0.05). 3. New implants showed mean bone density 56.7%, whereas TPS implants showed mean bone density 49.2% (statistically difference p<0.05). 4. New implants demonstrated mean removal torque values 40.5Ncm, whereas the mean removal torque values of TPS implants ranged 39.3Ncm. No statistical differences(p<0.05) were observed between two groups of implants nor was there any difference between the two implants at the clinical level.

• Biomedical Science Letters
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• v.11 no.1
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• pp.31-36
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• 2005

To evaluate the magnetic resonance imaging and electron microscopic findings of the hyperacute stage of cerebral fat embolism in cats and the time needed for the development of vasogenic edema. Magnetic resonance imaging was performed at 30 minutes (group 1, n=9) and at 30 minutes and 1, 2, 4, and 6 hours after embolization with triolein (group 2, n= 10). As a control for group 2, the same acquisition was obtained after embolization with polyvinyl alcohol particles (group 3, n=5). Electron microscopic examination was done in all cats. In group 1, the lesions were iso- or slightly hyperintense on T2-weighted (T2W) and diffusion-weighted (DWIs) images, hypointense on the apparent diffusion coefficient (ADC) map image, and markedly enhanced on the gadolinium-enhanced T1-weighted images (Gd-T1WIs). In group 2 at 30 minutes, the lesions were similar to those in group 1. Thereafter, the lesions became more hyperintense on T2WIs and DWIs and more hypoinfense on the ADC map image. In group 3, the lesions showed mild hyperintensity on T2WIs at 6 hours but hypointensity on the ADC map image from 30 minutes, with a tendency toward a greater decrease over time. Electron microscopic findings revealed discontinuity of the capillary endothelial wall, perivascular and interstitial edema, and swelling of glial and neuronal cells in groups 1 and 2. The lesions were hyperintense on T2WIs and DWIs, hypointense on the ADC map image, and enhanced on Gd-T1WIs. On electron microscopy, the lesions showed cytotoxic and vasogenic edema with disruption of the blood-brain barrier.

• Tuberculosis and Respiratory Diseases
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• v.40 no.3
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• pp.301-307
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• 1993

Intravascular bronchioloalveolar tumor is now recognized as a pulmonary form of hemangioendothelioma(HE). HE is an unusual tumor of adult life which is characterized by proliferation of an "epithelioid" or "spindle" endothelial cell. In the lung it usually presents as multiple bilateral slowly growing nodules less than 2 cm in diameter. The aetiology and pathogenesis of this disease are unknown. Spindle cell HE occurs at any age, but approximately one half of patient are 25 years of age or younger and males are affected twice more frequently than females. On light microscopic examination, the tumor show mild cellular atypia, nearly absent mitoses and electron-microscopic studies reveal evidence of endothelial cell differentiation. Intracytoplasmic localization of Factor VIII-related antigen is demonstrated on immunohistochemical study, which confirmed the endothelial origin of the tumor. No effective therapy is yet known for HE, but survival of this tumor can be quite long. However, one half of the patient have died, usually of progressive pulmonary insufficiency. This 19-yr-old male complained of Rt. chest pain and intermittent hemoptysis. Simple chest film and chest CT scan showed the Rt. pleural effusion, variable sized bilateral pulmonary nodules, irregular large heterogenous tumor with well enhancement and extensive necrosis in the anterior mediastinum. The mediastinal mass was biopsied and diagnosed as spindle cell HE by light microscopic finding and immunohistochemical studies.

• Korean Journal of Plant Resources
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• v.8 no.3
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• pp.303-318
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• 1995

Microscopic structures of epidermis and palynology and isozyme analysis were examined to find out the intergeneric and interspecific relationships and consequently to confirm the position of Hanabusaya aiatica as an endemic genus among 4 genera and 9 species belonging to the Hanabusaya asiatica, Korean endemic, and its allied groups. In the examination of microscopic structures of epidermis, cell patterns of perianth and ultrastructure of seed coat were found to be useful characters for the identification of the 4 genera and 9 species. Palynological characters such as microscopic structure and overall morphology of pollen grains were, however, not enough to distinguish them because of the great variabilities in these traits. Isozyme analysis showed that H. asiatica was very closly related to Campanula punctata and C. takesimana, though there were variations among populations and collected areas in some classified groups, depending on classified groups. Based on these results, the position of H. asiatica as an endemic genus was well confirmed.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.489-500
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• 2002

The purpose of this study was to evaluate newly fabricated tricalcium phosphate(TCP)/chitosan microgranuls as bone substitutes. TCP/chitosan microgranules were fabricated by dropping TCP-chitosan suspension into the NaOH/ethanol solution. The size of microgranules could be controllable via airflow rate. PDGF-BB was loaded into the fabricated granules via freeze-drying methods(300 ng/20 mg). To evaluate cell proliferation, cultured osteoblasts cell lines(MC3T3-El) was dropped on the BioOss(R), chitosan microgranules, TCP/chitosan microgranules and cultured for 1, 7 , 14, and 28 days. Scanning electron microscopic observation was done after 7 days of culture and light microscopic examination was done after 28 days of culture. PDGF-BB release from the microgranules was tested. Rabbit calvarial defects(8 mm in diameter) were formed and chitosan, TCP/chitosan, PDGF-TCP/chitosan microgranules, and BioGran(R) were grafted to test the ability of new bone formation. At SEM view, the size of prepared microgranules was 250-1000 um and TCP powders were observed at the surface of TCP/chitosan microgranules. TCP powders gave roughness to the granules and this might help the attachment of osteoblasts. The pores formed between microgranules might be able to allow new bone ingrowth and vascularization. There were no significant differences in cell number among BioOss(R) and two microgranules at 28 day. Light and scanning electron microscopic examination showed that seeded osteoblastic cells were well attached to TCP/chitosan microgranules and proliferated in a multi-layer. PDGF-BB released from TCP/chitosan microgranules was at therapeutic concentration for at least 1 week. In rabbit calvarial defect models, PDGF-TCP/chitosan microgranules grafted sites showed thicker bone trabeculae pattern and faster bone maturation than others. These results suggested that the TCP/chitosan microgranules showed the potential as bone substitutes.