다이프로피온산 베클로메타손과 부데소니드의 투여 용량에 따른 코르티솔 농도와 변화

이영승,김종구,이양근,최수미,송하숙,이용철 대한내과학회 1993 대한내과학회지 Vol.45 No.6

Background: Topical inhaled steroids, budesonide (Bu) and beclomethasone dipropionate (BDP) is now established in the management of chronic: asthma. These have high topical anti-inflammatory activity but low systemic activity. This study was performed to determine the effects of two inhaled corticosteroids, Bu and BDP, on the adrenocortical supression in thirty patients, eighteen chronic obstructive pumonary diseases and twelve bronchial asthma (aged 33-76 years). Methods: The adrenocortical function was assessed by measurement of plasma cortisol concentration at 8 o' clock in morning and free cortisol in 24-hour urine collection at interval, No steroid was taken during the pretreatment period of 10 days, thereafter each subject inhaled Bu or BDP aerosol, in daily doses of 800 or 1,600 micrograms for 12 days. The dose was delieved by metered dose inhaler (MDI) or diskhaler. No steroid was taken during the final 6 days of the study. Results: The plasma cortisol and 24-hour urinary free cortisol were decreased during the treatment period in patients inhaled Bu in daily doses of 800 and 1,600 micrograms. In contrast, plasma cortisol was decreased on the 12th day of treatment period in patients inhaled RDP, in daily doses of 800 micrograms (P less than 0.05). The plasma cortisol and 24-hour urinary free cortisol were decreased (P less than 0.05) on the 9 and 12 th day of treatment period in patients inhaled BDP in daily doses of 1,600 micrograms. Conclusion: These results suggested that suppression of the endogenous cortisol secretion occurs at inhaled budesonide and beclomethasone dipropionate is less suppressed on the adrenocortical function than budesonide in dose dependent fashion during the early periods,

다이캐스팅한 SiC 입자강화 알루미늄 복합재료의 피로균열 전파특성

김송희,윤여범,이기호,오준도,주희위,이지환 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.8

This study is to investigate the effect of load ratio on fatigue crack of die-cast SiC particulate aluminum composites. Fundamental fatigue crack propagation tests were performed with sub-sized C-T specimens at a load ratio of 0.1, 0.3 and 0.5 respectively. Crack closure measurements were conducted for explaning the effect of load ratio on fatigue crack growth. The experimental results showed that the fatigue crack growth rate increases with the load ratio, especially at near threshold. The composite reinforced with 20 vol.% SiC particles was better in fatigue crack growth resistance than that with 10 vol.% SiC particles. Through the measurement of Kop and ΔK at various R ratios the concept of effective stress intensity factor range ratio. U was reviewed to evaluate the stress ratio effect on fatigue crack growth. Relationships between U and variables such as ΔK and R were obtained empirically so that we could predict ΔK_(eff) that is of critical importance for the prediction of fatigue crack propagation rate.

반용융 성형된 A357 합금 성형품의 부식 및 기계적 특성에 관한 연구

김상식,이명호,이정환,유영빈,이재식,이한중 대한금속재료학회(대한금속학회) 2001 대한금속·재료학회지 Vol.39 No.8

The mechanical and corrosion properties of thixoformed A357 alloys were examined with different reheating temperatures, and the results were compared with those of permanent mold cast A357 alloys. It was found that the thixoforming process significantly improved the mechanical properties (i.e., tensile elongation, impact energy and resistance to fatigue crack propagation) and the corrosion resistance of A357 alloys. A 380% increase in tensile elongation and a 120% increase in impact energy were, for example, observed with thixoforming process of A357 alloy in the as-fabricated condition, as compared to the PMC counterparts. The impact energy was extremely sensitive to reheating temperature due to the coarsening of eutectic Si particles. The resistance to fatigue crack propagation for the thixoformed alloy was also much higher than that of permanent mold cast counterpart in the as-fabricated condition. The resistance to both general corrosion and stress corrosion cracking was also greatly improved with thixoforming process. The present observations strongly suggest that the enhancement with thixoforming A357 alloy is largely associated with the size and shape of eutectic Si particles.

Mn, Fe, Ni 첨가가 급속응고/분말야금법으로 제조된 Al-Zn-Mg-Cu 계 합금의 응력부식균열 거동에 미치는 영향

김상식,류재철,임수근,이명호 대한금속재료학회(대한금속학회) 1998 대한금속·재료학회지 Vol.36 No.11

Stress corrosion cracking behaviors of RS/PM Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Fe, 2%Mn, and 1%Fe+1%Ni, respectively, were examined in the present study. Each alloy was exposed to 3.5% NaCl aqueous solution under an applied stress of 200MPa for 5 and 20 days, respectively, and tensile tested in air. The alloys containing Fe+Ni and Mn showed a significant reduction in ductility after exposure for 20 days. SEM fractographic studies indicated that the size and depth of dimples, as well as the sign of plastic deformation around dimples, were greatly reduced after exposure for those alloys susceptible to stress corrosion cracking. The present study strongly suggested that hydrogen played an important role in stress corrosion cracking behaviors of Al-9Zn-2.5Mg-1Cu alloys with the addition of 2%Mn and 1%Fe+1%Ni, respectively.

경계요소법에 의한 아크균열의 응력확대계수 해석

백열선,이장규,우창기 한국산업안전학회 1999 한국안전학회지 Vol.14 No.4

In this paper, A circular arc crackered plate in biaxially stretched sheets was investigated in the boundary element method. The applications of fracture mechanics have traditionally concentrated on crack problems under an mode I, straight crack. However, many service failures occur from growth of cracks subjected to mixed mode Loadings. A rectangular plate with arc crack or slanted central crack, under biaxial tensile loading, was treated analytically and also solved numerically. The Results from BEM applying different loading conditions, crack length (a/W), arc angle(α) are presented and discussed The stress intensity factors are evaluated by the techniques of the J-integral. The decomposition method, used to decouple the stress intensity factors in mixed mode problems, is implemented by a considering a small circular contour path around each crack tip. The BIE method was successfully applied to a circular arc crackerd plate problem, also slanted centre cracked plate under mixed mode.

DMNQ S-64 Induces Apoptosis via Caspase Activation and Cyclooxygenase-2 Inhibition in Human Nonsmall Lung Cancer Cells

LIM, E.-S.,RHEE, Y.-H.,PARK, M.-K.,SHIM, B.-S.,AHN, K.-S.,KANG, H.,YOO, H.-S.,KIM, S.-H. Wiley (Blackwell Publishing) 2007 Annals of the New York Academy of Sciences Vol.1095 No.1

<P>Shikonin has been reported to induce apoptosis and inhibit angiogenesis in vivo and in vitro. 6-(1-propoxyiminoalkyl)-5,8-dimethoxyoxy 1,4-naphtoquinone S-64 (DMNQ S-64) was synthesized as a shikonin derivative. In this article, the underlying apoptotic mechanism of DMNQ S-64 was examined. DMNQ S-64 exerted cytotoxicity against A549 lung carcinoma cells with IC(50) of 27.3 microM. Apoptotic bodies were observed in DMNQ S-64-treated A549 cells by 4'-6-diamidino-2-phenylindole (DAPI) staining assay. DMNQ S-64 also increased sub-G1 DNA portion in a concentration-dependent manner by flow cytometric analysis. Western blotting has revealed that DMNQ S-64 effectively activates the expression of caspase 8, 9, and 3, cleaves poly (ADP-ribose) polymerase, and increases the ratio of Bax/Bcl-2. Furthermore, cytochrome c was released in a concentration-dependent manner by DMNQ S-64. Similarly, DMNQ S-64 significantly increased caspase 3 activity by enzyme-linked immunosorbent assay (ELISA). It also significantly inhibited the level of prostaglandin E2 (PGE(2)) by ELISA and downregulated the expression of cyclooxygenase-2 (COX-2) in a concentration-dependent manner. Taken together, DMNQ S-64 may exhibit cytotoxicity against A549 cells via caspase activation and COX-2 inhibition.</P>

<i>CYP2A6</i> and <i>ERCC1</i> polymorphisms correlate with efficacy of S-1 plus cisplatin in metastatic gastric cancer patients

Park, S R,Kong, S-Y,Nam, B-H,Choi, I J,Kim, C G,Lee, J Y,Cho, S J,Kim, Y W,Ryu, K W,Lee, J H,Rhee, J,Park, Y-I,Kim, N K Nature Publishing Group 2011 The British journal of cancer Vol.104 No.7

<P><B>Background:</B></P><P>We evaluated the association between polymorphisms of cytochrome P450 2A6 (<I>CYP2A6</I>)/excision repair cross-complementation group 1 (<I>ERCC1</I>)/X-ray repair cross-complementing group 1(<I>XRCC1</I>) and treatment outcomes of metastatic gastric cancer (MGC) patients treated with S-1/cisplatin.</P><P><B>Methods:</B></P><P>Among MGC patients (<I>n</I>=108), who received S-1 (40 mg m<SUP>−2</SUP> b.i.d., days 1–14) and cisplatin (60 mg m<SUP>−2</SUP>, day 1) every 3 weeks, we analysed the wild-type allele (<I>W</I>) and variants (<I>V</I>) of <I>CYP2A6</I> (<I>*4</I>, <I>*7, *9, *10</I>), and the polymorphisms of <I>ERCC1</I> (rs11615, rs3212986) and <I>XRCC1</I> (rs25487).</P><P><B>Results:</B></P><P>Patients having fewer <I>CYP2A6</I> variants had better response rates (<I>W</I>/<I>W vs W</I>/<I>V</I> other than <I>*1/*4 vs V</I>/<I>V</I> or <I>*1/*4</I>=66.7 <I>vs</I> 58.3 <I>vs</I> 32.3% <I>P</I>=0.008), time to progression (TTP) (7.2 <I>vs</I> 6.1 <I>vs</I> 3.5 months, <I>P</I>=0.021), and overall survival (23.2 <I>vs</I> 15.4 <I>vs</I> 12.0 months, <I>P</I>=0.004). <I>ERCC1 19442C</I>><I>A</I> (rs3212986) was also associated with response rate (<I>C/C</I>, 46.7% <I>vs C/A</I>, 55.3% <I>vs A/A</I>, 87.5%) (<I>P</I>=0.048) and TTP (4.4 <I>vs</I> 7.6 <I>vs</I> 7.9 months) (<I>P</I>=0.012). Patients carrying both risk genotypes of <I>CYP2A6</I> (<I>V</I>/<I>V</I> or <I>1/*4</I>) and <I>ERCC1 19442C</I>><I>A</I> (<I>C/C</I>) <I>vs</I> those carrying none showed an adjusted odds ratio of 0.113 (<I>P</I>=0.004) for response, and adjusted hazard ratios of 3.748 (<I>P</I>=0.0001) for TTP and 2.961 (<I>P</I>=0.006) for death.</P><P><B>Conclusion:</B></P><P>Polymorphisms of <I>CYP2A6</I> and <I>ERCC1 19442C</I>><I>A</I> correlated with the efficacy of S-1/cisplatin.</P>

석탄(石炭)의 유동층(流動層) 연소(燃燒)에 관(關)한 S. ENDRENYI와 B. PALANCZ의 수학적(數學的) 수정(修正)모델(비표면적(比表面積) 변화(變化)의 영향(影響))

김명준,이관석,서정윤,Kim, M.J.,Rhee, K.S.,Seo, J.Y. 대한설비공학회 1988 설비저널 Vol.17 No.1

A numerical analysis of the mathematical model for fluidized bed coal combustion has been performed. Based on the physical nature of the specific surface variation due to the decreasing of coal particle diameter according to the combustion process, the modified model which has been added the specific surface variation to the S.ENDRENYI and B.PALANCZ's mathematical model was established in this study. From the numerical analysis of these two models, it was found that the perfect combustion time is increasing largely at least 5 seconds in the modified model in comparison with that of the S.ENDRENYI and B.PALANCZ's model, and the bed temperature and the coal particle surface temperature during the main combustion period represent constant with time in the S.ENDRENYI and B.PALANCZ's model, on the other hand, these properties are decreasing linearly with time in the modified model.

Direct Evidence of Allele-Specific Binding of CTCF and MeCP2 to <b><i>Tsix</i></b> in a HPRT-Deficient Female F₁ Hybrid Mouse Cell Line

Son, J.,Min, N.Y.,Choi, J.-H.,Ko, Y.J.,Liang, W.,Rhee, S.,Lee, K.-H. S. Karger AG 2012 Cytogenetic and genome research Vol.138 No.1

<P>Abstract</P><P>Mammalian dosage compensation requires silencing of one of the two X chromosomes in females and is controlled by the X inactivation center (Xic). Xic contains many of the regulatory elements for the mutual interplay of X-inactive specific transcript <I>(Xist)</I> and <I>Tsix</I>, the antisense counterpart of <I>Xist</I>. The regulatory elements control X chromosome inactivation (XCI) via the formation of DNA-DNA and DNA-protein complexes with <I>cis</I>- and <I>trans</I>-acting factors. However, the process-dependent regulation of <I>Xist/Tsix</I> by these elements in each XCI process remains largely unknown. In this study, a 6-thioguanine-resistant female F<SUB>1</SUB> hybrid mouse cell line (designated HOBMSKI2) was constructed from a cross between a female HPRT-deficient transgenic mouse (designated BM3) and a male wild type <I>Mus spretus</I> mouse (designated MS), which enabled the direct discrimination of both allele-specific expression of X-linked genes and allele-specific binding of proteins associated with XCI due to DNA polymorphisms between BM3 and MS. Using this cell line, we found that <I>Tsix</I> on the active X chromosome (Xa) was not expressed in somatic cells despite the fact that CTCF, which ensures <I>Tsix</I> expression in embryonic stem cells, was still bound to the 5′ end of <I>Tsix</I> on Xa, implying that CTCF may function differently during each XCI process and its <I>trans</I>-activating activity for <I>Tsix</I> expression may be lost in the maintenance process. In addition, the monoallelic expression of <I>Tsix</I> on Xa was inhibited by epigenetic modification of the chromatin in the maintenance process, which was mediated by protein complexes recruited by MeCP2. The results indicate the value of HOBMSKI2 in directly detecting the allele-specific binding of CTCF and MeCP2 to the 5′ end of <I>Tsix</I>. The HOBMSKI2 mouse line is a versatile and useful resource for studying the molecular mechanism of the XCI process.</P><P>Copyright © 2012 S. Karger AG, Basel</P>

Sulfiredoxin, the cysteine sulfinic acid reductase specific to 2-Cys peroxiredoxin: its discovery, mechanism of action, and biological significance

Rhee, S G,Jeong, W,Chang, T-S,Woo, H A Springer-Verlag 2007 Kidney international Vol.72 No.suppl106

Peroxiredoxin (Prx) is a family of bifunctional proteins that exhibit peroxidase and chaperone activities. Prx proteins contain a conserved Cys residue that undergoes a redox change between thiol and disulfide states. 2-Cys Prx enzymes, a subgroup of Prx family, are intrinsically susceptible to reversible hyperoxidation to cysteine sulfinic acid during catalysis. Cysteine hyperoxidation of Prx was shown to result in loss of peroxidase activity and a concomitant gain of chaperone activity. Reduction of sulfinic Prx enzymes, the first known biological example of such a reaction, is catalyzed by sulfiredoxin (Srx) in the presence of ATP. Srx appears to exist solely to support the reversible sulfinic modification of 2-Cys Prx enzymes. Srx specifically binds to 2-Cys Prx enzymes by recognizing several critical surface-exposed residues of the Prxs, and transfer the γ-phosphate of ATP to their sulfinic moiety, using its conserved cysteine as the phosphate carrier. The resulting sulfinic phosphoryl ester is reduced to cysteine after oxidation of four thiol equivalents.Kidney International (2007) 72, S3–S8. doi:10.1038/sj.ki.5002380