• Title/Summary/Keyword: Sequential mediation

Search Result 32, Processing Time 0.016 seconds

The Relationship between External Contingencies of Self-Worth and Materialism of Undergraduates: Self-Discrepancy and the Stability of Self-Esteem as Mediators (대학생의 외적 자기가치 수반성과 물질주의의 관계: 자기 불일치, 자존감 안정성의 매개효과)

  • Shin, Jiyun;Seol, Kyoung Ok
    • Korean Journal of Culture and Social Issue
    • /
    • v.28 no.3
    • /
    • pp.373-392
    • /
    • 2022
  • The present study aimed to emprically verify the materialistic pursuits process of undergraduates by applying the escape theory of materialism(Donnelly et al., 2016). Among the six steps of Donnelly's model, the first step is percieving that the fall short of high standards of life, as measured by external contingencies of self-worth. The second step is blaming the self for falling short of standards, as measured by self-discrepancy. The third step of high aversive self-awareness is measured by low stability of self-esteem. A total of 465(203 male and 262 female) college students participated in the online survey and the model was tested using structural equation model. We found that the relationship of external contingencies of self-worth and materialism was mediated by self-discrepancy and there was a sequential mediation effect of self-discrepancy and the stability of self-esteem. The direct effect of external contingencies of self-worth on materialism was also significant. This study is meaningful in that it used the escape theory to emprically verify the materialistic pursuit process of Korean undergraduates living in a meritocratic society.

Apoptotic Effect of Proso Millet Grains on Human Breast Cancer MDA-MB-231Cells Is Exerted by Activation of BAK and BAX, and Mitochondrial Damage-mediated Caspase Cascade Activation (기장 종자 유래 추출물의 인간 유방암 MDA-MB-231 세포에 대한 세포독성에 관련된 미토콘드리아 손상-의존적 아폽토시스 유도 효과)

  • Do Youn Jun;Cho Rong Han;Young Ho Kim
    • Journal of Life Science
    • /
    • v.33 no.1
    • /
    • pp.15-24
    • /
    • 2023
  • To examine the antitumor effect of proso millet grains, whether proso millet grains exert apoptotic activity against human cancer cells was investigated. When the cytotoxicity of 80% ethanol (EtOH) extract of proso millet grains was tested against various cancer cells using MTT assay, more potent cytotoxicity was observed against human breast cancer MDA-MB-231 cells than against other cancer cells. When the EtOH extract was evaporated to dryness, dissolved in water, and then further fractionated by sequential extraction using four organic solvents (n-hexane, methylene chloride, ethyl acetate, and n-butanol), the BuOH fraction exhibited the highest cytotoxicity against MDA-MB-231 cells. Along with the cytotoxicity, TUNEL-positive apoptotic nucleosomal DNA fragmentation and several apoptotic responses including BAK/BAX activation, mitochondria membrane potential (Δψm) loss, mitochondrial cytochrome c release into the cytosol, activation of caspase-8/-9/-3, and degradation of poly (ADP-ribose) polymerase (PARP) were detected. However, human normal mammary epithelial MCF-10A cells exhibited a significantly lesser extent of sensitivity compared to malignant MDA-MB-231 cells. Irrespective of Fas-associated death domain (FADD)-deficiency or caspase-8-deficiency, human T acute lymphoblastic leukemia Jurkat cells displayed similar sensitivities to the cytotoxicity of BuOH fraction, excluding an involvement of extrinsic apoptotic mechanism in the apoptosis induction. These results demonstrate that the cytotoxicity of BuOH fraction from proso millet grains against human breast cancer MDA-MB-231 cells is attributable to intrinsic apoptotic cell death resulting from BAK/BAX activation, and subsequent mediation of mitochondrial damage-dependent activation of caspase cascade.