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Effects of ${Zn}^{2+}$ on the Activities of Electron Transport and Photophosphorylation of Barley Chloroplasts (보리 엽록체의 전자전달과 광인산화 활성에 미치는 ${Zn}^{2+}$의 영향)

  • 김지숙;홍영남;권영명
    • Journal of Plant Biology
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    • v.28 no.1
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    • pp.69-77
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    • 1985
  • The degree of The degree of The degree of ${Zn}^{2+}$ effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested.${Zn}^{2+}$treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal ${Zn}^{2+}$level (10$^{-6}$ M). The other was that the different concentrations of ${Zn}^{2+}$was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of ${Zn}^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of ${Zn}^{2+}$concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of ${Zn}^{2+}$in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, ${Zn}^{2+}$(2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested. Z $n^{2+}$ treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal Z $n^{2+}$ level (10$^{-6}$ M). The other was that the different concentrations of Z $n^{2+}$ was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of Z $n^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of Z $n^{2+}$ concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of Z $n^{2+}$ in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, Z $n^{2+}$ (2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.effect on the photosynthetic electron transport and photophosphorylation activities in barley chloroplasts has been tested. Z $n^{2+}$ treatment was done in the 2 ways. One was that it was added into the chloroplasts suspensions isolated from the plants grown under the normal Z $n^{2+}$ level (10$^{-6}$ M). The other was that the different concentrations of Z $n^{2+}$ was applied in each growth medium. Then, it was not added into the chloroplasts suspensions isolated from the plants. PS II activity in both way of the treatments was more severely inhibited than PS I by the increment of Z $n^{2+}$ concentration. The photophosphorylation activity measured by pH measurement was gradually decreased with the increase of Z $n^{2+}$ concentration in both ways, too. However, it was shown that M $n^{2+}$ could be near fully overcome the inhibitory effect of Z $n^{2+}$ in PS II, and $Mg^{2+}$ could also reduce the Z $n^{2+}$ inhibition in the photophosphorylation. In the low concentrations of $Mg^{2+}$ (3 to 5$\times$10$^{-3}$ M) in the suspension, Z $n^{2+}$ (2$\times$10$^{-5}$ M) could increase the activity of photophosphorylation. As compares to other cations, Z $n^{2+}$ caused less inhibitory effect on the photophosphorylation activity than Cu, Cd, but more than Pb and Ni. It may be assumed that a complex from reaction of Z $n^{2+}$ and mercaptoethanol was produced and it could reduce the stability of CPI band during SDS-PAGE.ld reduce the stability of CPI band during SDS-PAGE.

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A study on the factors to affect the career success among workers with disabilities (지체장애근로자의 직업성공 요인에 관한 연구)

  • Lee, Dal-Yob
    • 한국사회복지학회:학술대회논문집
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    • 2003.10a
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    • pp.185-216
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    • 2003
  • This study was aimed at investigating important factors influencing career success among regular workers. The current researcher scrutinized the degree to which variables and factors affect the career success and occupational turnover rates of the research participants. At the same tune, two hypothetical path models established by the researcher were examined using linear multiple regression methods and the LISREL. After examining the differences among the factors of career success, a comparison was made between the disabled worker group and the non-disabled worker group. A questionnaire using the 5-point Likert scale was distributed to a group of 374 workers with disabilities and 463 workers without disabilities. For the data analysis purpose, the structural equation model, factor analysis, correlation analysis, and multiple regression analysis were carried out. The results of this study ran be summarized as follows. First, the results of factor analysis showed important categories of conceptual themes of career success. The initial conceptual factor model did not accord with the empirical one. A three-factorial model revealed categories of personal, family, and organizational factor respectively. The personal factor was composed of the self-esteem and self-efficiency. The family factor was consisted of the multi-roles stress and the number of children. Finally, the organizational factor was composed of the capacity for utilizing resources, networking, and the frequency of mentoring. In addition, the total 10 sub areas of career success were divided by two important aspects; the subjective career success and the objective career success. Second, both research participant groups seemed to be influenced by their occupational types. However, all predictive variables excluding the wage rate and the average length of work years had significant impact on job success for the disabled work group, while all the variables excluding the frequency of advice and length of working years had significant impact on job success for the non-disabled worker group. Third, the turnover rate was significantly influenced by the age and the experience of turnover of the research participants. However, the number of co-workers was the strongest predictive variable for the worker group with disabilities, but the occupation choice variable for the worker group without disabilities. For the disabled worker group, the turnover rate was differently influenced by the type of occupation, the length of working years, while multi-role stress and the average working years at the time of turnover for the worker group without disabilities. Fifth, as a result of verifying the hypothetical path model, it showed that the first model was somewhat proper and could predict the career success on both research participant groups. In the second model, the Chi-square, the degree of freedom (($x^2=64.950$, df=61, P=0.341), and the adjusted Goodness of Fit Index (AGFI) were .964, and the Comparative Fit Index (CFI) were .997, and the Root Mean Squared Residual (RMR) was respectively. .038. The model was best fitted and could predict the career success more highly because the goodness of fit index in the whole models was within the allowed range. In conclusion, the following research implications can be suggested. First, the occupational type of research participants was one of the most important variables to predict the career success for both research participant groups. It means that people with disabilities require human development services including education. They need to improve themselves in this knowledge-based society. Furthermore, for maintaining the career success, people with disabilities should be approached by considering the subjective career success aspects including wages and the promotion opportunities than the objective career success aspects.

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Plasma Activity of Lysosomal Enzymes in Active Pulmonary Tuberculosis (활동성 폐결핵 환자에서 혈중 리소솜 효소의 활성도)

  • Koh, Youn-Suck;Choi, Jeong-Eun;Kim, Mi-Kyung;Lim, Chae-Man;Kim, Woo-Sung;Chi, Hyun-Sook;Kim, Won-Dong
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.5
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    • pp.646-653
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    • 1995
  • Background: The confirmative diagnosis of pulmonary tuberculosis(Tb) can be made by the isolation of Mycobacterium Tuberculosis(MTb) in the culture of the sputum, respiratory secretions or tissues of the patients, but positive result could not always be obtained in pulmonary Tb cases. Although there are many indirect ways of the diagnosis of Tb, clinicians still experience the difficulty in the diagnosis of Tb because each method has its own limitation. Therefore development of a new diagnostic tool is clinically urgent. It was reported that silica cause some lysosomal enzymes to be released from macrophages in vitro and one of these enzymes is elevated in workers exposed to silica dust and in silicotic subjects. In pulmonary Tb, alveolar macrophages are known to be activated after ingestion of MTb. Activated macrophages can kill MTb through oxygen free radical species and digestive enzymes of lysosome. But if macrophages allow the bacilli to grow intracellularly, the macrophages will die finally and local lesion will enlarge. Then it is assumed that the lysosomal enzymes would be released from the dead macrophages. The goal of this investigation was to determine if there are differences in the plasma activities of lysosomal enzymes, ($\beta$-glucuronidase(GLU) and $\beta$-N-acetyl glucosaminidase(NAG), among the groups of active and inactive pulmonary Tb and healthy control, and to see if there is any possibility that the plasma activity of GLU and NAG can be used as diagnostic indicies of active pulmonary Tb. Methods: The plasma were obtained from 20 patients with bacteriologically proven active pulmonary Tb, 15 persons with inactive Tb and 20 normal controls. In 10 patients with active pulmonary Tb, serial samples after 2 months of anti-Tb medications were obtained. Plasma GLU and NAG activities were measured by the fluorometric methods using 4-methylumbelliferyl substrates. All data are expressed as the mean $\pm$ the standard error of the mean. Results: The activites of GLU and NAG in plasma of the patients with active Tb were $21.52{\pm}3.01$ and $325.4{\pm}23.37$(nmol product/h/ml of plasma), respectively. Those of inactive pulmonary Tb were $24.87{\pm}3.78$, $362.36{\pm}33.92$ and those of healthy control were $25.45{\pm}4.05$, $324.44{\pm}28.66$(nmol product/h/ml of plasma), respectively. There were no significant differences in the plasma activities of both enzymes among 3 groups. The plasma activities of GLU at 2 months after anti-Tb medications were increased($42.18{\pm}5.94$ nmol product/h/ml of plasma) in the patients with active pulmonary Tb compared with that at the diagnosis of Tb(P-value <0.05). Conclusion: The results of the present investigation suggest that the measurement of the plasma activities of GLU and NAG in the patients with active pulmonary Tb could not be a useful method for the diagnosis of active Tb. Further investigation is necessary to define the reasons why the plasma activities of the GLU was increased in the patients with active pulmonary Tb after Tb therapy.

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Study about the clinical features and Pulmonary function Tst of Endobronchial Tuberculosis (기관지결핵의 임상상 및 폐기능검사에 관한 연구)

  • Chung, Hee-Soon;Lee, Jae-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.43 no.2
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    • pp.147-158
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    • 1996
  • Background : Endobronchial tuberculosis(ET) is known to affect frequently young female and serious complication like bronchial stenosis would occur if early diagnosis and treatment for ET is not performed immediately. But ET shows normal chest roentgenogram in about 10% of patients, and is often confused with bronchial asthma because ET presents clinical features like cough, dyspnea, wheezing in history and physical examination. The pulmonary function test(PFT) feature of ET is not well known, but when we consider the fact that ET is pathophysiologically different from bronchial asthma, if there is any feature of PFT in ET, and we know it, PFT will be very helpful for diagnosis and follow up of ET. Methods : We performed both PFT and bronchoscopy in 68 ET patients who visited Boramae hospital, and were confirmed as ET by bronchoscopic biopsy and were followed prospectively from November 1991 to March 1995. After history taking and physical examination, we performed chest roentgenogram, complete blood count, sputum AFB stain and culture, and also performed PFT before anti-tuberculosis chemotherapy. PFT was classified as restrictive, if only PVC was reduced below 80%, and obstructive, if only FEV1 was reduced below 75%. In the case of both FVC and FEV1 were reduced, PFT was classified as restrictive if FEY1/FVC was greater than 75%, and mixed if FEV1/FVC was reduced below 75%. We repeated the PFT and bronchoscopy for 68 ET patients who were proven by biopsy in the first month and sixth month after starting anti-tuberculosis chemotherapy, and studied the feature and change of PFT of the ET and the relation between PFT and the bronchoscopic finding, and obtained following results. Results: 1) Number of male patients was 12, and that of female patient was 56, and mean age was $35.4{\pm}17yr$.(17-74yr). Clinical symptom was in the order of cough(86.8%), dyspnea(63.2%), fever(17.6%) and hemoptysis (10.3%), and the wheezing and stridor were audible among the 40 patients(58.4%) in the physical examination. 2) Hemoglobin level was below 12g/dl among 25 patients (36.8%), and WBC level was above $10,000/mm^3$ among 9 patients(13.2%) and ESR was above 20 among 46 patients (67.6%) and AFB stain and culture were positive among 50 patients(73.5%). 3) The dominant roentgenographic finding of ET was fibronodular feature in 35 patients(51.5%), pneumonic feature in 14 patients (20.6%), collapse in 11 patients(16.2%), mass-like lesion in 3 patients(4.4%), cavitary lesion in 2 patients(2.9%), and normal in 3 patients(4.4%). 4) PFT feature at the time of diagnosis of ET was normal in 16 patients(23.5%), restrictive pattern in 32 patients (47%), obstructive in 4 patients(5.8%), and mixed in 14 patients(23.5%). So restrictive pattern was the dominate feature of ET. 5) The PFT feature was little correlated with the gross finding of bronchoscopy, but the change of PFT during treatment of ET showed relatively good correlation with the change of bronchoscopic finding. 6) FVC(2.30L vs. 2.61L) and FEV1(1.74L vs. 2.06L) increased significantly (p < 0.01), but FEV1/FVC(82% vs. 83%) and PEF(3.45L/sec vs. 3.95L/sec) did not change significantly after 1 month of treatment (p > 0.01), and there was no significant change among all parameters during first and sixth month of treatment(p > 0.01). Conclusion : PFT may be useful in the diagnosis and treatment follow up of ET but further study would be needed to confirm it.

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Comparision of Chest Radiographs and Pulmonary Function in Coal Workers' Pneumoconiosis and Welders' Lung (탄광부 진폐증과 용접공 폐증에 있어 흉부-X선 소견과 폐기능의 비교)

  • Park, Dong-Youl;Hwang, Joo-Ho;Kang, Byung-Son;Chung, Chan-Su;Kim, Wha-Jo
    • Tuberculosis and Respiratory Diseases
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    • v.42 no.5
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    • pp.713-722
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    • 1995
  • Background: Chest X-ray of coal workers' pneumoconiosis and shipyard welders' lung show similar and regular opacities mostly, it is very difficult that we distinguish the former from the latter by only chest X-ray. so we performed this study to understand the progression of the disease and to provide the disease by considering pulmonary function and other factors in proportion to the profusion of small regular opacities of chest X-ray in both groups. Method: 430 coal workers' pneumoconiosis were compared with 311 shipyard welders' lung by the number, the age, the duration of dust exposure, %vital capacity(%VC), %FEV1.0, the type of ventilatory impairment, the combined pulmonary disease according to the profusion of small regular opacities on the chest radiographs, which were classified into category 0/1, category 1, and category 2. Result: 1) the percent of category 2 in coal workers' pneumoconiosis was 54.4%. the percent of category 1, and category 2 in welders' lung were 60.0%, 7.4%. the progression to the category 2 was higher in coal workers' pneumoconiosis than in welders' lung 2) The mean age was higher in coal workers' pneumoconiosis than in welders' lung, significantly increased in proportion to the progresion of profusion of small regular opacities in both groups 3) There was no difference in the duration of dust exposure by category 1/0, but the duration of dust exposure by category 1, 2 in coal workers' pneumoconiosis more significantly increased than in welders' lung. the duration in the proportion of category 2 to category 0/1, 1 significantly increased in the proportion to small regular opacities in coal workers' pneumoconiosis. but there was no significant difference in the proportion to small regular opacities in duration of dust exposure in welders' lung. 4) There was no significant difference of mean values of %VC(%vital capacity)in both groups except for category 1. the mean values of %VC had no relationship between the progression of small regular opacities in both groups. 5) The mean values of %FEV1.0 decreased more significantly in coal workers' pneumoconiosis than in welders' lung except for category 0/1. and decreased significantly in proportion to the profusion of small regular opacities in coal workers' pneumoconiosis. there was significant difference of %FEV1.0 in the proportion of category 2 to category 011 in welders' lung. 6) there were no significant difference of %FEV1.0, %VC in smoker and nonsmoker in both groups. 7) With regard to the type of ventilation in both groups in coal workers' pneumoconiosis 21.4 percent of patients belonged to the restrictive type, 11.6 percent to the obstructive type, 5.6 percent to the combined type, but in welders' lung 21.8 percent to the restrictive type, 2.9 percent to the obstructive type, 1.9 percent to the combined type. 8. in the pulmonary disease, the incidence of the pulmonary tuberculosis was the most in both groups, was more in coal workers' pneumoconiosis than welders' lung Conclusion: If we compare coal workers' pneumoconiosis with electric arc welders'lung by considering pulmonary function and other factors in proportion to the profusion of chest X-ray, I think that we will have the better result in understanding the progression of the disease and provision of the disease in both groups.

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Triptolide-induced Transrepression of IL-8 NF-${\kappa}B$ in Lung Epithelial Cells (폐상피세포에서 Triptolide에 의한 NF-${\kappa}B$ 의존성 IL-8 유전자 전사활성 억제기전)

  • Jee, Young-Koo;Kim, Yoon-Seup;Yun, Se-Young;Kim, Yong-Ho;Choi, Eun-Kyoung;Park, Jae-Seuk;Kim, Keu-Youl;Chea, Gi-Nam;Kwak, Sahng-June;Lee, Kye-Young
    • Tuberculosis and Respiratory Diseases
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    • v.50 no.1
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    • pp.52-66
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    • 2001
  • Background : NF-${\kappa}B$ is the most important transcriptional factor in IL-8 gene expression. Triptolide is a new compound that recently has been shown to inhibit NF-${\kappa}B$ activation. The purpose of this study is to investigate how triptolide inhibits NF-${\kappa}B$-dependent IL-8 gene transcription in lung epithelial cells and to pilot the potential for the clinical application of triptolide in inflammatory lung diseases. Methods : A549 cells were used and triptolide was provided from Pharmagenesis Company (Palo Alto, CA). In order to examine NF-${\kappa}B$-dependent IL-8 transcriptional activity, we established stable A549 IL-8-NF-${\kappa}B$-luc. cells and performed luciferase assays. IL-8 gene expression was measured by RT-PCR and ELISA. A Western blot was done for the study of $I{\kappa}B{\alpha}$ degradation and an electromobility shift assay was done to analyze NF-${\kappa}B$ DNA binding. p65 specific transactivation was analyzed by a cotransfection study using a Gal4-p65 fusion protein expression system. To investigate the involvement of transcriptional coactivators, we perfomed a transfection study with CBP and SRC-1 expression vectors. Results : We observed that triptolide significantly suppresses NF-${\kappa}B$-dependent IL-8 transcriptional activity induced by IL-$1{\beta}$ and PMA. RT-PCR showed that triptolide represses both IL-$1{\beta}$ and PMA-induced IL-8 mRNA expression and ELISA confirmed this triptolide-mediated IL-8 suppression at the protein level. However, triptolide did not affect $I{\kappa}B{\alpha}$ degradation and NF-$_{\kappa}B$ DNA binding. In a p65-specific transactivation study, triptolide significantly suppressed Gal4-p65T Al and Gal4-p65T A2 activity suggesting that triptolide inhibits NF-${\kappa}B$ activation by inhibiting p65 transactivation. However, this triptolide-mediated inhibition of p65 transactivation was not rescued by the overexpression of CBP or SRC-1, thereby excluding the role of transcriptional coactivators. Conclusions : Triptolide is a new compound that inhibits NF-${\kappa}B$-dependent IL-8 transcriptional activation by inhibiting p65 transactivation, but not by an $I{\kappa}B{\alpha}$-dependent mechanism. This suggests that triptolide may have a therapeutic potential for inflammatory lung diseases.

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Prognostic Value of the Expression of p53 and bcl-2 in Non-Small Cell Lung Cancer (비소세포폐암에서 p53과 bcl-2의 발현이 예후에 미치는 영향)

  • Yang, Seok-Chul;Yoon, Ho-Joo;Shin, Dong-Ho;Park, Sung-Soo;Lee, Jung-Hee;Keum, Joo-Seob;Kong, Gu;Lee, Jung-Dal
    • Tuberculosis and Respiratory Diseases
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    • v.45 no.5
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    • pp.962-974
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    • 1998
  • Background: Alteration of p53 tumor suppressor genes is most frequently identified in human neoplasms, including lung carcinoma. It is well known that bcl-2 oncoprotein protects cells from apoptosis. Recent studies have demonstrated that bcl-2 expression is associated with favorable prognosis for patients with non-small cell lung carcinoma. However, the precise biologic role of bcl-2 in the development of these tumors is still obscure. p53 and bcl-2 have important regulatory influence in the apoptotic pathway and thus their relationship is of interest in tumorigenesis, especially lung cancer. Purpose: The author investigated to know the prognostic significance of the expression of p53 and bcl-2 in radically resected non-small cell lung cancer. Method: 84 cases of formalin-fixed paraffin-embedded blocks from resected primary non-small cell lung cancer from 1980 to 1994 at Hanyang University Hospital were available for both clinical follow-up and immunohistochemical staining using monoclonal antibodies for p53 and bcl-2. Results : The histologic classification of the tumor was based on WHO criteria., and the specimens included 45 squamous cell carcinomas(53.6%), 28 adeonocarcinomas(33.3%) and 11 large cell carcinomas(13.1 %). p53 immunoreactivity was noted in 47 cases of 84 cases(56.0%). bcl-2 immunoreactivity was noted in 15 cases of 84 cases(17.9%). The mean survival duration was $64.23{\pm}10.73$ months in bcl-2 positive group and $35.28{\pm}4$. 39 months in bcl-2 negative group. The bcl-2 expression was significantly correlated with survival in radically resected non-small cell lung cancer patients(p=0.03). The mean survival duration was $34.71{\pm}6.12$ months in p53 positive group and $45.35{\pm}6.30$ months in p53 negative group(p=0.21). The p53 expression was not predictive for survival. There was no correlation between combination of the different status of p53 and bcl-2 expression in our study. Conclusions : The interaction and the regulation of new biologic markers, such as those involved in the apoptotic pathway, are complex. bcl-2 overexpression is a good prognostic factor in non-small cell lung cancer and p53 expression is not significantly associated with the prognostic factor in non-small cell lung cancer.

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The micro-tensile bond strength of two-step self-etch adhesive to ground enamel with and without prior acid-etching (산부식 전처리에 따른 2단계 자가부식 접착제의 연마 법랑질에 대한 미세인장결합강도)

  • Kim, You-Lee;Kim, Jee-Hwan;Shim, June-Sung;Kim, Kwang-Mahn;Lee, Keun-Woo
    • The Journal of Korean Academy of Prosthodontics
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    • v.46 no.2
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    • pp.148-156
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    • 2008
  • Statement of problems: Self-etch adhesives exhibit some clinical benefits such as ease of manipulation and reduced technique-sensitivity. Nevertheless, some concern remains regarding the bonding effectiveness of self-etch adhesives to enamel, in particular when so-called 'mild' self-etch adhesives are employed. This study compared the microtensile bond strengths to ground enamel of the two-step self-etch adhesive Clearfil SE Bond (Kuraray) to the three-step etch-and- rinse adhesive Scotchbond Multi-Purpose (3M ESPE) and the one-step self-etch adhesive iBond (Heraeus Kulzer). Purpose: The purpose of this study was to determine the effect of a preceding phosphoric acid conditioning step on the bonding effectiveness of a two-step self-etch adhesive to ground enamel. Material and methods: The two-step self-etch adhesive Clearfil SE Bond non-etch group, Clearfil SE Bond etch group with prior 35% phosphoric acid etching, and the one-step self-etch adhesive iBond group were used as experimental groups. The three-step etch-and-rinse adhesive Scotchbond Multi-Purpose was used as a control group. The facial surfaces of bovine incisors were divided in four equal parts cruciformly, and randomly distributed into each group. The facial surface of each incisor was ground with 800-grit silicon carbide paper. Each adhesive group was applied according to the manufacturer's instructions to ground enamel, after which the surface was built up using Light-Core (Bisco). After storage in distilled water at $37^{\circ}C$ for 1 week, the restored teeth were sectioned into enamel beams approximately 0.8*0.8mm in cross section using a low speed precision diamond saw (TOPMET Metsaw-LS). After storage in distilled water at $37^{\circ}C$ for 1 month, 3 months, microtensile bond strength evaluations were performed using microspecimens. The microtensile bond strength (MPa) was derived by dividing the imposed force (N) at time of fracture by the bond area ($mm^2$). The mode of failure at the interface was determined with a microscope (Microscope-B nocular, Nikon). The data of microtensile bond strength were statistically analyzed using a one-way ANOVA, followed by Least Significant Difference Post Hoc Test at a significance level of 5%. Results: The mean microtensile bond strength after 1 month of storage showed no statistically significant difference between all adhesive groups (P>0.05). After 3 months of storage, adhesion to ground enamel of iBond was not significantly different from Clearfil SE Bond etch (P>>0.05), while Clearfil SE Bond non-etch and Scotchbond Multi-Purpose demonstrated significantly lower bond strengths (P<0.05), with no significant differences between the two adhesives. Conclusion: In this study the microtensile bond strength to ground enamel of two-step self-etch adhesive Clearfil SE Bond was not significantly different from three-step etch-and-rinse adhesive Scotchbond Multi-Purpose, and prior etching with 35% phosphoric acid significantly increased the bonding effectiveness of Clearfil SE Bond to enamel at 3 months.

Crystal Structures of Full Dehydrated $Ca_{35}Cs_{22}Si_{100}Al_{92}O_{384}$and $Ca_{29}Cs_{34}Si_{100}Al_{92}O_{384}$ ($Ca^{2+}$ 이온과 $Cs^+$ 이온으로 치환되고 탈수된 두개의 제올라이트 X $Ca_{35}Cs_{22}Si_{100}Al_{92}O_{384}$$Ca_{29}Cs_{34}Si_{100}Al_{92}O_{384}$의 결정구조)

  • Jang, Se Bok;Song, Seung Hwan;Kim, Yang
    • Journal of the Korean Chemical Society
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    • v.40 no.6
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    • pp.427-435
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    • 1996
  • The structures of fully dehydrated $Ca^{2+}$- and $Cs^+$-exchanged zeolite X, $Ca_{35}Cs_{22}Si_{100}Al_{92}O_{384}$($Ca_{35}Cs_{22}$-X; a=25.071(1) $\AA)$ and $Ca_{29}Cs_{34}Si_{100}Al_{92}O_{384}$($Ca_{29}Cs_{34}$-X; a=24.949(1) $\AA)$, have been determined by single-crystal X-ray diffraction methods in the cubic space group Fd3 at $21(1)^{\circ}C.$ Their structures were refined to the final error indices $R_1$=0.051 and $R_2$=0.044 with 322 reflections for $Ca_{35}Cs_{22}$-X, and $R_1$=0.058 and $R_2$=0.055 with 260 reflections for $Ca_{29}Cs_{34}$-X; $I>3\sigma(I).$ In both structures, $Ca^{2+}$ and $Cs^+$ ions are located at five different crystallographic sites. In dehydrated $Ca_{35}Cs_{22}$-X, sixteen $Ca^{2+}$ ions fill site I, at the centers of the double 6-rings(Ca-O=2.41(1) $\AA$ and $O-Ca-O=93.4(3)^{\circ}).$ Another nineteen $Ca^{2+}$ ions occupy site II (Ca-O=2.29(1) $\AA$, O-Ca-O=118.7(4)') and ten $Cs^+$ ions occupy site II opposite single six-rings in the supercage; each is $1.95\AA$ from the plane of three oxygens (Cs-O=2.99(1) and $O-Cs-O=82.3(3)^{\circ}).$ About three $Cs^+$ ions are found at site II', 2.27 $\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.23(1) $\AA$ and $O-Cs-O=75.2(3)^{\circ}).$ The remaining nine $Cs^+$ ions are statistically distributed over site Ⅲ, a 48-fold equipoint in the supercages on twofold axes (Cs-O=3.25(1) $\AA$ and Cs-O=3.49(1) $\AA).$ In dehydrated $Ca_{29}Cs_{34}$-X, sixteen $Ca^{2+}$ ions fill site I(Ca-O=2.38(1) $\AA$ and $O-Ca-O=94.1(4)^{\circ})$ and thirteen $Ca^{2+}$ ions occupy site II (Ca-O=2.32(2) $\AA$, $O-Ca-O=119.7(6)^{\circ}).$ Another twelve $Cs^+$ ions occupy site II; each is $1.93\AA$ from the plane of three oxygens (Cs-O=3.02(1) and $O-Cs-O=83.1(4)^{\circ})$ and seven $Cs^+$ ions occupy site II'; each is $2.22\AA$ into sodalite cavity from their three-oxygen plane (Cs-O=3.21(2) and $O-Cs-O=77.2(4)^{\circ}).$ The remaining sixteen $Cs^+$ ions are found at III site in the supercage (Cs-O=3.11(1) $\AA$ and Cs-O=3.46(2) $\AA).$ It appears that $Ca^{2+}$ ions prefer sites I and II in that order, and that $Cs^+$ ions occupy the remaining sites, except that they are too large to be stable at site I.

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Changes in blood pressure and determinants of blood pressure level and change in Korean adolescents (성장기 청소년의 혈압변화와 결정요인)

  • Suh, Il;Nam, Chung-Mo;Jee, Sun-Ha;Kim, Suk-Il;Kim, Young-Ok;Kim, Sung-Soon;Shim, Won-Heum;Kim, Chun-Bae;Lee, Kang-Hee;Ha, Jong-Won;Kang, Hyung-Gon;Oh, Kyung-Won
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.2 s.57
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    • pp.308-326
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    • 1997
  • Many studies have led to the notion that essential hypertension in adults is the result of a process that starts early in life: investigation of blood pressure(BP) in children and adolescents can therefore contribute to knowledge of the etiology of the condition. A unique longitudinal study on BP in Korea, known as Kangwha Children's Blood Pressure(KCBP) Study was initiated in 1986 to investigate changes in BP in children. This study is a part of the KCBP study. The purposes of this study are to show changes in BP and to determine factors affecting to BP level and change in Korean adolescents during age period 12 to 16 years. A total of 710 students(335 males, 375 females) who were in the first grade at junior high school(12 years old) in 1992 in Kangwha County, Korea have been followed to measure BP and related factors(anthropometric, serologic and dietary factors) annually up to 1996. A total of 562 students(242 males, 320 females) completed all five annual examinations. The main results are as follows: 1. For males, mean systolic and diastolic BP at age 12 and 16 years old were 108.7 mmHg and 118.1 mmHg(systolic), and 69.5 mmHg and 73.4 mmHg(diastolic), respectively. BP level was the highest when students were at 15 years old. For females, mean systolic and diastolic BP at age 12 and 16 years were 114.4 mmHg and 113.5 mmHg(systolic) and 75.2 mmHg and 72.1 mmHg(diastolic), respectively. BP level reached the highest point when they were 13-14 years old. 2. Anthropometric variables(height, weight and body mass index, etc) increased constantly during the study period for males. However, the rate of increase was decreased for females after age 15 years. Serum total cholesterol decreased and triglyceride increased according to age for males, but they did not show any significant trend fer females. Total fat intake increased at age 16 years compared with that at age 14 years. Compositions of carbohydrate, protein and fat among total energy intake were 66.2:12.0:19.4, 64.1:12.1:21.8 at age 14 and 16 years, respectively. 3. Most of anthropometric measures, especially, height, body mass index(BMI) and triceps skinfold thickness showed a significant correlation with BP level in both sexes. When BMI was adjusted, serum total cholesterol showed a significant negative correlation with systolic BP at age 12 years in males, but at age 14 years the direction of correlation changed to positive. In females serum total cholesterol was negatively correlated with diastolic BP at age 15 and 16 years. Triglyceride and creatinine showed positive correlation with systolic and diastolic BP in males, but they did not show any correlation in females. There was no consistent findings between nutrient intake and BP level. However, protein intake correlated positively with diastolic BP level in males. 4. Blood pressure change was positively associated with changes in BMI and serum total cholesterol in both sexes. Change in creatinine was associated with BP change positively in males and negatively in females. Students whose sodium intake was high showed higher systolic and diastolic BP in males, and students whose total fat intake was high maintained lower level of BP in females. The major determinants on BP change was BMI in both sexes.

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