• Title/Summary/Keyword: microscopic mechanism

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Malignant Pericardial Effusion Incidentally Detected by Tc-99m MDP Bone Scintigraphy (Tc-99m MDP 골 스캔에서 우연히 발견된 악성 심낭 삼출)

  • Lim, Seok-Tae;Sohn, Myung-Hee;Kwak, Jae-Yong;Yim, Chang-Yeol
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.4
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    • pp.291-292
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    • 2001
  • We report a case of malignant pericardial effusion originated from adenocarcinoma of the lung incidentally diagnosed by bone scintigraphy, prior to echocardiographic detection. A 76 year-old man with adenocarcinoma of the lung underwent Tc-99m MDP bone scintigraphy to evaluate skeletal metastasis. Anterior images of the chest of the bone scintigraphy unexpectedly showed diffuse increased activity in the region of the heart surrounded by an oval-shaped band of increased activity corresponding to the periphery of the cardiac silhouette (Fig. 1). There was no evidence of bony metastasis. Pericardial effusion was confirmed by echocardiography (Fig. 2) and malignant cells were revealed by subsequent microscopic examination of the pericardial fluid. Bone scintigraphy using Tc-99m phosphate compounds is commonly used to detect bony metastasis in cancer patients. Tc-99m phosphate compounds occasionally accumulate in extra-osseous sites, including $pleural^{1,2)},\;pericardial^{3,4)},\;and\;ascitic\;fluids^{5,6)}$. It has been reported that their accumulation in serous effusions should strongly suggest $malignancy^{1-6)}$. The exact mechanism for accumulation of Tc-99m phosphate compounds in serous effusions is unclear. Several investigators have proposed that the radiopharmaceuticals exuded directly from peripheral vessels to the serous cavity due to increased vascularity and vascular permeability, and bleeding by disruption of blood vessels due to cancerous $infiltration^{5,6)}$.

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Antifungal Mechanism and Properties of Antibiotic Substances produced by Bacillus subtilis YB-70 as a Biological Control Agent

  • Kim, Yong-Su;Kim, Sang-Dal
    • Journal of Microbiology and Biotechnology
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    • v.4 no.4
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    • pp.296-304
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    • 1994
  • Antibiotic substances were produced by Bacillus subtilis YB-70, a potential biocontrol agent found to suppress root-rot of eggplant (Solanum melonggena L) caused by Fusarium solani, in a dextrose glutamate medium and isolated by isoelectric precipitation. Partial purification was performed by column chromatography on silica gel with two solvent systems: chloroform-methanol and methanol-chloroform-water as eluting solvents, This active fraction YBS-1 s contained antifungal activity were soluble in ethanol, methanol, and water, but were not soluble in other solvents including acetone, butanol, ethyl ether, dimethylformamide, propanol, and etc. High performance liquid chromatography and thin layer chromatographic separation of YBS-1s showed that they have been composed of three biological active bands that were named YBS-1A, -1B, and -1C. The substances were stable to heat and resistant to protease. YBS-1s were active against a wide range of plant pathogenic fungi but did not inhibit the growth of bacteria and yeasts. They were not only fungicidal but also fungistatic against chlamydospores of F. solani. The $ED_{50}$ values for the chlamydospore germination and the germ-tube growth of F. solani were $O.725\mu\textrm{m}/ml\;and\;O.562\mu\textrm{m}/ml$, respectively. Microscopic observations proved the substances restricted the growth of phytopathogenic fungus F. solani by spore burst followed by dissolving of its germ-tube, and caused abnormal hyphal swelling after application to chlamydospores or growing hyphae. Cultural filtrate of B; subtilis YB-70 also suppressed the development of root-rot of eggplant in pot tests.

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EFFECT OF ZOLEDRONATE TO BONE HEALING PROCESS AFTER ILIAC BONE GRAFT INTO MAXILLARY SINUS IN RABBIT (Zoledronate가 토끼장골에서 채취한 상악동 골이식부위 치유에 미치는 영향)

  • Song, Jun-Ho;Lee, Soo-Woon;Park, Sang-Jun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.35 no.3
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    • pp.158-163
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    • 2009
  • Objective : Recently, we are interested in bisphosphonate related osteonecrosis of the jaw (BRONJ). Most of patients with osteonecrosis have taken medicine bisphosphonate for a long time. But the mechanism of osteonecrosis in BRONJ was not clarified yet. The aim of this study is to evaluate the difference of bone healing effect after bone graft from ilium to maxillary sinus in rabbits between zoledronate-treated and zoledronate-not treated groups. Method : The subjects was divided into two groups. The experimental group was 9 rabbits, treated with intraperitoneal administration of zoledronate(0.06mg/kg) once per week for 3 weeks. In control group, same procedure was applied but administerd saline instead of zoledronate. After 4 weeks, surgical operation under local anesthesia (ketamine 3.0cc, xylazine 1.0cc) was done. At postoperative 1, 2, 4, 8 weeks later, each rabbits were sacrificed and removed the bone grafted area. Gross, radiologic and histopathologic exminations of bone grafted area were performed. Result : There were no conspicuous differences of radiological findings between experimental and control groups in any experimental weeks. In experimental group, new bone formation appeared earlier than control group at 1 week after operation, and maturation of bony tissue were more conspicuous at 2 and 4 weeks after operation, compared with control group. In 8 weeks after operation, similar microscopic findings were noted in both groups. Conclusion : In the bisphosphonate-treated rabbits, new bone formation in the bone grafted area appeared earlier and bony maturation was more concpicuous, even though there were no significant differences of gross and radiological findings. These findings suggest that bisphosphonate might be promotive effect in the healing process in early stage after administration.

Analysis of Biological Effect of DBD-type Non-thermal Atmospheric Pressure Plasma on Saccharomyces Cerevisiae

  • Park, Gyung-Soon;Baik, Ku-Yeon;Kim, Jung-Gil;Kim, Yun-Jung;Lee, Kyung-Ae;Choi, Eun-Ha;Uhm, Hwan-Sup;Jung, Ran-Ju;Cho, Kwang-Sup
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.08a
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    • pp.337-337
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    • 2011
  • Application of plasma technology on microbial sterilization has been frequently studied. In spite of accumulating number of studies, many have been focused on bacteria. Reports on eukaryotic yeasts and filamentous fungi are limited. In addition, mechanism of plasma effect still needs to be clarified. In this study, we analyzed the effect of non-thermal atmospheric pressure plasma on the budding yeast, Saccharomyces cerevisiae using DBD-type device. When yeast cells were exposed to plasma (at 2 mm distance) and then cultured on YPD-agar plate, number of cells survived (shown as colony) were reduced proportionally to exposure time. More than 50% reduction in number of colonies were observed after twice exposure of 5min. each. Colonies much smaller than those of control (no plasma exposure) were appeared after twice exposure of 5 min. each. It seems that small colonies are resulted from delayed cell growth due to the damage caused by plasma treatment. Microscopic analysis demonstrates that yeast cells treated with plasma for 5 min. twice have more rough and shrinked shape compared to oval shape with smooth surface of control.

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Kinetic Study on Nucleophilic Substitution Reactions of 4-Chloro-2-nitrophenyl X-Substituted-benzoates with Cyclic Secondary Amines: Effect of Substituent X on Reactivity and Reaction Mechanism

  • Jeon, Seong Hoon;Kim, Hyun Soo;Han, Young Joon;Kim, Min-Young;Um, Ik-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.34 no.10
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    • pp.2983-2988
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    • 2013
  • Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of 4-chloro-2-nitrophenyl X-substituted-benzoates (1a-1h) with a series of cyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The Hammett plot for the reactions of 1a-1h with piperidine consists of two intersecting straight lines, while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X $ = 1.25 and r = 0.58, indicating that the nonlinear Hammett plot is not due to a change in the rate-determining step (RDS) but is caused by ground-state stabilization through resonance interactions for substrates possessing an electron-withdrawing group in the benzoyl moiety. The Br${\o}$nsted-type plot for the reactions of 4-chloro-2-nitrophenyl benzoate (1d) with a series of cyclic secondary amines curves downward with ${\beta}_2$ = 0.85, ${\beta}_1$ = 0.24, and $pK_a{^o}$ = 10.5, implying that a change in RDS occurs from the $k_2$ step to the $k_1$ process as the $pK_a$ of the conjugate acid of the amine exceeds 10.5. Dissection of $k_N$ into the microscopic rate constants $k_1$ and $k_2/k_{-1}$ ratio associated with the reaction of 1d reveals that $k_2$ is dependent on the amine basicity, which is contrary to generally held views.

Effects of Aucuba japonica Extract on Oral Wound Healing (구강점막의 창상치유에 대한 식나무(Aucuba japonica) 추출물의 효과)

  • Shim Kyung-Mi;Kim Se-Eun;Choi Jeong-Yun;Park Joo-Cheol;Jeong Soon-Jeong;Lee Jae-Yeong;Bae Chun-Sik;Park Don-Hee;Kim Do-Man;Jeong Moon-Jin;Kang Seong-Soo
    • Journal of Veterinary Clinics
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    • v.23 no.1
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    • pp.55-60
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    • 2006
  • Aucuba japonica has variable pharmacological effects such as hepatoprotective, choleretic, hemodynamic, antimicrobial, and anti-inflammatory activities. This study was performed to investigate the effects of Aucuba japonica extract on oral wound healing. Aucubin was extracted from Aucuba japonica, and injected on either side of buccal mucosa of male mice. Artificial full thickness wounds were made on the site with 1.5 mm biopsy punch under sterile technique. The specimens had taken on day 1, 3, and 5 with 4 mm biopsy punch. Light microscopic examination and quantitative histologic analysis were performed for reepithelization, inflammatory cell infiltration. Reepithelization of the aucubin (0.1%) group was earlier than the control group. And the number of inflammatory cells of the aucubin group was lesser than the control group. In view of the results so far achieved, the aucubin extracted from Aucuba japonica may be useful for oral wound healing and it can be applied as a topical agent on the oral wound. Further research should be performed on the mechanism of aucubin on oral wound healing and proper formulation for effective topical agents.

Study on the Effects of Flows on the Acceleration of the Grooving Corrosion in the ERW Pipe (ERW강관에서 홈부식의 가속화에 미치는 유동의 영향에 관한 연구)

  • Kim, Jae-Seong;Kim, Yong;Lee, Bo-Young
    • Journal of Welding and Joining
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    • v.26 no.4
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    • pp.85-91
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    • 2008
  • The grooving corrosion is caused mainly by the different microstructures between the matrix and weld which is formed during the rapid heating and cooling cycle in welding. By this localized corrosion reaction of pipes, it evolves economic problems such as the early damage of industrial facilities and pipe lines of apartment, and water pollution. So lots of researches were carried out already about grooving corrosion mechanism of ERW carbon steel pipe but there is seldom study for water hammer happened by fluid phenomenon and corrosion rate by flow velocity. In this study, the analysis based on hydrodynamic and fracture mechanics was carried out. ANSYS, FLUENT and STAR-CD were used for confirmation of flow phenomenon and stress on the pipe. As the results, fatigue failure is able to be happened by water hammer and grooving corrosion rate is increased cause by turbulent. Grooving corrosion is happened on the pipe, then friction loss of fluid is occurred from corroded part. Erosion can be happened enough in corroded region of microscopic size that wear "V" form. Also pipe is able to be damaged by water hammer effects because of corroded region is general acting as a notch effects. Corrosion depth was more than half of total thickness, it can be damaged from water hammer pressure.

Oxidative Stress by Arsenic Trioxide in Cultured Rat Cardiomyocytes, $H_9C_2$ Cells (배양 심근세포에서 저농도 삼산화비소에 의한 산화적 스트레스 발생)

  • Park Eun-Jung;Park Kwang-Sik
    • Environmental Analysis Health and Toxicology
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    • v.21 no.1 s.52
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    • pp.71-79
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    • 2006
  • Epidemiologic studies have showed a close correlation between arsenic exposure and heart disease such as, cardiovascular problem, ischemic heart disease, infarction, atherosclerosis and hypertension in human. It may increase the mortality of high risk group with heart disease. Regarding the mechanism studies of heart failure, blood vessel, vascular smooth muscle cells and endothelial cells have long been focused as the primary targets in arsenic exposure but there are only a few studies on the cardiomyocytes. In this study, the generation of oxidative stress by low dose of arsenic trioxide was investigated in rat cardiomyocytes. By direct measurement of reactive oxygen species and fluorescent microscopic observation using fluorescent dye 2',7'-dichlorofluorescin diacetate, reactive oxygen species were found to be generated without cell death, where cells are treated with 0.1 ppm arsenic for 24 hours. With the induction of reactive oxygen species, GSH level was decreased by the same treatment. However, DNA damage did not seem to be serious by DAPI staining, while high dose of arsenic (2 ppm for 24 hrs) caused fragmentation of DNA. To identify the molecular biomarkers of low-dose arsenic exposure, gene expression was also investigated with whole genome microarray. As results, 9,022 genes were up-regulated including heme oxygenase-l and glutathione S-transrerase, which are well-known biomarkers of oxidative stress. 9,404 genes were down-regulated including endothelial type gp 91-phox gene by the treatment of 0.1 ppm arsenic for 24 hours. This means that biological responses of cardiomyocytes may be altered by ROS induced by low level arsenic without cell death, and this alteration may be detected clearly by molecular biomarkers such as heme oxygenase-1.

Ultrastructure of Substance P Immunopositive Axons in the Human Dental Pulp

  • Moon, Byung Hee;Ha, Jung Hong;Han, Hye Min;Kim, Tae Heon;Park, Sook Kyung;Bae, Yong Chul
    • International Journal of Oral Biology
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    • v.43 no.3
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    • pp.155-160
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    • 2018
  • There exists very little information on the ultrastructure of substance P immunopositive (+) fibers in the human dental pulp, which may help in understanding the mechanism for substance P associated pulpal inflammatory pain. To address this issue, we investigated the presence of substance P+ fibers in the human dental pulp by light- and electron-microscopic immunohistochemistry. Light microscopy revealed that substance P+ fibers ran within neurovascular bundles in the radicular pulp and in the core of coronal pulp. They were also frequently present in the peripheral pulp. Substance P+ fibers showed beads like swellings interconnected by thin axonal strand, in a manner similar to bouton en passants and interconnecting axonal strand in the spinal cord. Electron microscopy revealed that almost all the substance P+ axons were unmyelinated. The axonal swellings of the substance P+ contained numerous clear round vesicles (40-50 nm in diameter) and many large dense-cored vesicles (80-110 nm in diameter) as well as many mitochondria. The vesicles and mitochondria were rarely observed in the thin axonal strand interconnecting the swellings. Intimate interrelationship or synaptic structure between the swellings of substance P+ axon and nearby pulpal cells or axons was not found. These findings suggest co-release of substance P and glutamate from the substance P+ pulpal axons and its action on nearby structures in a paracrine manner.

IDENTIFICATION OF RECEPTOR ACTIVATOR OF NUCLEAR $FACTOR-{\kappa}B$ LIGAND(RANKL) AND OSTEOPROTEGERIN(OPG) IN ODONTOGENIC KERATOCYST (치성각화낭종에서 receptor activator nuclear $factor-{\kappa}B$ ligand(RANKL)와 osteoprotegrin(OPG) 발현에 관한 연구)

  • Ahn, Dong-Kil;Ha, Woo-Hun;Kim, Seong-Sik;Hwang, Dae-Seok;Kim, Yong-Deok;Shin, Sang-Hun;Kim, Uk-Kyu;Kim, Jong-Ryoul;Chung, In-Kyo
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.29 no.1
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    • pp.24-32
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    • 2007
  • The odontogenic keratocyst(OKC) is a common developmental odontogenic cyst and represents approximately 11% of odontogenic cysts. It is decided by microscopic and histopathologic determinant rather than by clinical appearance. In this study, expression of RANKL and OPG in OKC in relation to age and gender of patient and recurrence, location of lesion were examined through immuno- histochemical study. The RANKL and OPG antibody staining were used. The obtained result were as follow. 1. Positive immunoreactivity to RANKL/OPG in all specimens was found. 2. There was no significant difference in immunohistochemical expression of RANKL relating to recurrence, location of OKCs and age, gender of patients. 3. There was no significant difference in immunohistochemical expression of OPG relating to recurrence, location of OKCs and age, gender of patients. From above results, it is suggested that activation of osteoclasts by RANKL is an important mechanism by which OKCs cause bone destruction.