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CERTAIN CLASS OF FRACTIONAL CALCULUS OPERATOR WITH TWO FIXED POINTS

  • Kwon, Oh-Sang
    • East Asian mathematical journal
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    • v.14 no.1
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    • pp.107-116
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    • 1998
  • This paper deals with functions of the form $f(z)=a_1z-{\sum}{\limits}_{n=2}^{\infty}a_nz^n(a_1>0,\;a_n{\geqslant}0)$ with $(1-{\mu})f(z_0)/z_0+{\mu}f'(z_0)=1(-1. We introduce the class $\varphi({\mu},{\eta},{\gamma},{\delta},A,B;\;z_0)$ with generalized fractional derivatives. Also we have obtained coefficient inequalities, distortion theorem and radious problem of functions belonging to the calss $\varphi({\mu},{\eta},{\gamma},{\delta},A,B;\;z_0)$.

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Identification of Differentially Expressed Genes by TCDD in Human Bronchial Cells: Toxicogenomic Markers for Dioxin Exposure

  • Park, Chung-Mu;Jin, Kyong-Suk;Lee, Yong-Woo
    • Biomedical Science Letters
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    • v.18 no.1
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    • pp.1-9
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    • 2012
  • Differentially expressed genes by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were identified in order to evaluate them as dioxin-sensitive markers and crucial signaling molecules to understand dioxin-induced toxic mechanisms in human bronchial cells. Gene expression profiling was analyzed by cDNA microarray and ten genes were selected for further study. They were cytochrome P450, family 1, subfamily B, polypeptide 1 (CYP1B1), S100 calcium binding protein A8 (calgranulin A), S100 calcium binding protein A9 (calgranulin B), aldehyde dehydrogenase 1 family, member A3 (ALDH6) and peroxiredoxin 5 (PRDX5) in up-regulated group. Among them, CYP1B1 was used as a hallmark for dioxin and sharply increased by TCDD exposure. Down-regulated genes were IK cytokine, interferon-induced protein with tetratricopeptide repeats 1 (IFIT1), nuclease sensitive element binding protein 1 (NSEP1), protein tyrosine phosphatase type VI A, member 1 (PTP4A1), ras oncogene family 32 (RAB32). Although up-regulated 4 genes in microarray were coincided with northern hybridization, down-regulated 5 genes showed U-shaped expression pattern which is sharply decreased at lower doses and gradually increased at higher doses. These results introduce some of TCDD-responsive genes can be sensitive markers against TCDD exposure and used as signaling cues to understand toxicity initiated by TCDD inhalation in pulmonary tissues.

Synthesis and Guest Binding Properties of Cyclophanes Containing Two Benzo[b]furan Rings

  • Park, Kwang-Hee;Kim, Sun-Hyuk;Park, Joon-Woo
    • Bulletin of the Korean Chemical Society
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    • v.25 no.11
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    • pp.1635-1640
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    • 2004
  • The cyclophanes 1a-d containing two benzo[b]furan rings connected by various bridges have been prepared and their binding behaviors with N-benzylphenethylammonium cation 2 were examined by NMR titration method. The successive alkylation reactions of 4-hydroxyl groups and then 2-hydroxyl groups of 2,4-dihydroxybenzophenonse gave macrocycles 5a-c. Photoirradiation of the macrocycles 5a-c with 350 nm mercury lamp followed by dehydration afforded the cyclophanes 1a-c. Hydrolysis of two ester groups pendant on a bridge of 1b produced the carboxyl group-containing cyclophane 1d. The cyclophane 1a having a p-xylene bridge showed 1 : 1 binding with 2 with the binding constant of $36{\pm}6M^{-1}$ in 3 : 1 $CDCl_3$/methanol-$d_4$ solvent, while 1b and 1c which have neutral flexible bridges exhibited no appreciable binding with 2. The disodium salt of 1d showed much higher binding affinity for 2 forming 1 : 1 and 1 : 2 complexes.

Backbone assignment of HMGB1 A-box and molecular interaction with Hoxc9DBD studied by paramagnetic probe

  • Choi, Ji Woong;Park, Sung Jean
    • Journal of the Korean Magnetic Resonance Society
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    • v.25 no.2
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    • pp.17-23
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    • 2021
  • High mobility group protein B1 (HMGB1) is a highly conserved, non-histone, chromatin associated nuclear protein encoded by HMGB1 gene. HMGB1 proteins may be general co-factors in Hox-mediated transcriptional activation that facilitate the access of Hox proteins to specific DNA targets. It is unclear that the exact binding interface of Hoxc9DBD and HMGB1. To identify the interface and binding affinity of Hoxc9DBD and HMGB1 A-box, the paramagnetic probe, MTSL was used in NMR titration experiment. It is attached to the N-terminal end of HMGB1 A-box by reaction with thiol groups. The backbone assignment of HMGB1 A-box was achieved with 3D NMR techinques. The 15N-labeled HMGB1 A-box was titrated with MTSL-labeled Hoxc9DBD respectively. Based on the chemical shift changes we can identify the interacting residues and further map out the binding sites on the protein structure. The NMR titration result showed that the binding interface of HMGB1 A-box is around loop-1 between helix-1 and helix-2. In addition, the additional contacts were found in N- and C-terminus. The N-terminal arm region of Hoxc9DBD is the major binding region and the loop between helix1 and helix2 is the minor binding region.

Protein phosphatase 4 dephosphorylates phosphofructokinase-1 to regulate its enzymatic activity

  • Jaehong Park;Dong-Hyun Lee
    • BMB Reports
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    • v.56 no.11
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    • pp.618-623
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    • 2023
  • Most cancer cells utilize glucose at a high rate to produce energy and precursors for the biosynthesis of macromolecules such as lipids, proteins, and nucleic acids. This phenomenon is called the Warburg effect or aerobic glycolysis- this distinct characteristic is an attractive target for developing anticancer drugs. Here, we found that Phosphofructokinase-1 (PFK-1) is a substrate of the Protein Phosphatase 4 catalytic subunit (PP4C)/PP4 regulatory subunit 1 (PP4R1) complex by using immunoprecipitation and in vitro assay. While manipulation of PP4C/PP4R1 does not have a critical impact on PFK-1 expression, the absence of the PP4C/PP4R1 complex increases PFK-1 activity. Although PP4C depletion or overexpression does not cause a dramatic change in the overall glycolytic rate, PP4R1 depletion induces a considerable increase in both basal and compensatory glycolytic rates, as well as the oxygen consumption rate, indicating oxidative phosphorylation. Collectively, the PP4C/PP4R1 complex regulates PFK-1 activity by reversing its phosphorylation and is a promising candidate for treating glycolytic disorders and cancers. Targeting PP4R1 could be a more efficient and safer strategy to avoid pleiotropic effects than targeting PP4C directly.

Genetic Polymorphism of MTHFR A1298C and Esophageal Cancer Susceptibility: A Meta-analysis

  • Tan, Xiang;Wang, Yong-Yong;Dai, Lei;Liao, Xu-Qiang;Chen, Ming-Wu
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1951-1955
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    • 2013
  • Background: Associations between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and esophageal cancer risk have been reported in many articles recently, but results were controversial. Therefore the present meta-analysis was conducted to to provide a more precise estimation. Methods: Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of associations. Results: Finally, six case-control studies involving a total of 1,302 cases and 2,391controls for the A1298C polymorphism were included. The meta-analysis showed that significantly increased risk for Asians (CC versus AA, OR=3.799, 95%CI=1.541-9.365, P=0.004; CCversusCA+AA, OR=3.997, 95%CI=1.614-9.900, P=0.003) and Caucasians (CC versus AA, OR=1.797, 95%CI=1.335-2.418, P=0.000; CC+CA versus AA,OR=1.240, 95%CI=1.031-1.492, P=0.022; CCversusCA+AA, OR=1.693, 95%CI=1.280-2.240, P=0.000). In addition, there was an association with risk for both ESCC (CC versus AA, OR=2.529, 95%CI=1.688-3.788, P=0.000; CCversusCA+AA, OR=2.572, 95%CI=1.761-3.758, P=0.000) and esophageal adenocarcinoma (EAC) (CC versus AA, OR=1.592, 95%CI=1.139-2.227, P=0.007; CC+CA versus AA,OR=1.247, 95%CI=1.016-1.530, P=0.035; CCversusCA+AA, OR=1.466, 95%CI=1.069-2.011, P=0.018). Conclusion: This meta-analysis suggested associations of the A1298C polymorphism with increased risk of esophageal cancer in both Asians and Caucasians. In addition, we found that the MTHFR A1298C polymorphism might influence risk ofESCC and EAC in the overall studies.

Family Study of TAP Gene Polymorphism and HLA-TAP Haplotypes in Koreans (가계조사를 통한 한국인의 TAP 유전자의 다형성과 HLA-TAP 일배체형 분포에 관한 연구)

  • Whang, Dong Hee;Park, Myoung Hee
    • IMMUNE NETWORK
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    • v.2 no.4
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    • pp.248-255
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    • 2002
  • Background: TAP1 and TAP2 are two ABC transporter genes located within the class II region of the human MHC. Their protein products form a heterodimer whose function is to transport peptides from the cytoplasm into the endoplasmic reticulum. This study was performed to examine the polymorphism of TAP genes and the distribution of HLA-TAP haplotypes in the Korean population through family analysis. Methods: The subjects used in this study were 50 healthy Korean families consisting of 233 individuals. TAP1 (codons 333 and 637) and TAP2 (codons 379, 565, 577, 651, 665, and 687) typings were carried out by the PCR-restriction fragment length polymorphism (RFLP) method. HLA-DRB1 and DQB1 genotyping results from a previous study were used for HLA-TAP haplotype analysis. Results: The number (gene frequency) of TAP1 and TAP2 alleles detected were 3 for TAP1 (A 81.5%, B 17.0%, and C 1.5%) and 8 for TAP2 (A1 32.0%, A2 12.5%, B 34.0%, Bky2 6.5%, C 7.0%, D 3.0%, E 4.5%, and G 0.5%). Eleven TAP1-TAP2 haplotypes were observed with $frequency{\geq}1%$, among which 4 haplotypes (A-B, B-A1, A-Bky2, and C-E) showed weak but significant positive linkage disequilibrium (P<0.05). When DRB1-DQB1 haplotypes were extended to TAP1 and TAP2 loci, much diversification of haplotypes was observed: 19 different DRB1-DQB1 haplotypes formed 58 different haplotypes extended to TAP1 and TAP2 loci. These results add more evidence to the view that recombination hotspot is present within and around TAP gene region. Conclusion: The allele frequencies of TAP1 and TAP2 genes and the distribution of TAP1-TAP2 and HLA-TAP haplotypes were studied in Koreans based on a family study.

Cytochrome P450 1 gene in Eel, Anguilla japonica: cloning and expression patterns after exposure to benzo[a]pyrene (뱀장어(Anguilla japonica)에서 Cytochrome P450 1 gene 클로닝 및 benzo[a]pyrene 노출에 따른 발현 분석)

  • Jo, Hyun Ho;Kim, Ju An;Lee, Seung Hyun;Chung, Joon Ki
    • Journal of fish pathology
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    • v.33 no.2
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    • pp.153-161
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    • 2020
  • Cytochrome P450(CYP) gene is involved in the biotransformation of drugs and environmental pollutants. In this study, we analyzed the nucleotide sequence of the Anguilla japonica CYP1(AjCYP1) family gene and examined the relative expression of AjCYP1A, AjCYP1B and AjCYP1C1 in response to the exposure to environmental pollutants. After exposure to B[a]P 20mg/kg bw, the expression of AjCYP1 family gene increased over time. Among four tissues examined (liver, spleen, gill and kidney), AjCYP1 family gene was expressed significantly in the kidney. Compared with the control group, AjCYP1A was expressed about 5-fold at 48 hr, AjCYP1B about 6-fold at 24 hr, and AjCYP1C1 about 4-fold at 24 hr. However, after exposure to B[a]P 200mg/kg bw, AjCYP1A did not change in all tissues. On the other hand, AjCYP1B was expressed at about 4-fold at 24 hr in the spleen and 4-fold at 48 hr in the gill. Finally AjCYP1C1 was expressed 3.7-fold and 4.3-fold in the spleen and kidneys at 48 hr, respectively. Taken together, our results suggest that the expression of AjCYP1 gene in eel tissues might be used as a useful tool to assess the exposure to environmental pollutants in aquaculture system.

APPROXIMATION OF COMMON FIXED POINTS OF NON-SELF ASYMPTOTICALLY NONEXPANSIVE MAPPINGS

  • Kim, Jong-Kyu;Dashputre, Samir;Diwan, S.D.
    • East Asian mathematical journal
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    • v.25 no.2
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    • pp.179-196
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    • 2009
  • Let E be a uniformly convex Banach space and K a nonempty closed convex subset which is also a nonexpansive retract of E. For i = 1, 2, 3, let $T_i:K{\rightarrow}E$ be an asymptotically nonexpansive mappings with sequence ${\{k_n^{(i)}\}\subset[1,{\infty})$ such that $\sum_{n-1}^{\infty}(k_n^{(i)}-1)$ < ${\infty},\;k_{n}^{(i)}{\rightarrow}1$, as $n{\rightarrow}\infty$ and F(T)=$\bigcap_{i=3}^3F(T_i){\neq}{\phi}$ (the set of all common xed points of $T_i$, i = 1, 2, 3). Let {$a_n$},{$b_n$} and {$c_n$} are three real sequences in [0, 1] such that $\in{\leq}\;a_n,\;b_n,\;c_n\;{\leq}\;1-\in$ for $n{\in}N$ and some ${\in}{\geq}0$. Starting with arbitrary $x_1{\in}K$, define sequence {$x_n$} by setting {$$x_{n+1}=P((1-a_n)x_n+a_nT_1(PT_1)^{n-1}y_n)$$ $$y_n=P((1-b_n)x_n+a_nT_2(PT_2)^{n-1}z_n)$$ $$z_n=P((1-c_n)x_n+c_nT_3(PT_3)^{n-1}x_n)$$. Assume that one of the following conditions holds: (1) E satises the Opial property, (2) E has Frechet dierentiable norm, (3) $E^*$ has Kedec -Klee property, where $E^*$ is dual of E. Then sequence {$x_n$} converges weakly to some p${\in}$F(T).

A FIXED POINT APPROACH TO THE STABILITY OF QUARTIC LIE ∗-DERIVATIONS

  • Kang, Dongseung;Koh, Heejeong
    • Korean Journal of Mathematics
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    • v.24 no.4
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    • pp.587-600
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    • 2016
  • We obtain the general solution of the functional equation $f(ax+y)-f(x-ay)+{\frac{1}{2}}a(a^2+1)f(x-y)+(a^4-1)f(y)={\frac{1}{2}}a(a^2+1)f(x+y)+(a^4-1)f(x)$ and prove the stability problem of the quartic Lie ${\ast}$-derivation by using a directed method and an alternative fixed point method.