Fu Jen Catholic University

About: Fu Jen Catholic University is a education organization based out in Taipei, Taiwan. It is known for research contribution in the topics: Population & Medicine. The organization has 6842 authors who have published 9512 publications receiving 171005 citations. The organization is also known as: FJU & Fu Jen.

From racial discrimination to risky sex: prospective relations involving peers and parents.

Abstract: Compared with other racial groups in the United States, African Americans suffer higher rates of sexually transmitted infections (STIs) such as HIV/AIDS, gonorrhea, chlamydia, and syphilis (Centers for Disease Control and Prevention, 2009a, 2009b). These race-based differences in STIs are often substantial. For instance, although African Americans comprise only 13% of the total U.S. population, they account for 51% of all new HIV/AIDS diagnoses (Centers for Disease Control and Prevention, 2009a). Controlling for socioeconomic status (SES) attenuates, but does not eliminate, these differences, which suggests that other, more psychosocial factors are involved in promoting risky sexual behavior (Dressler, Oths, & Gravlee, 2005; Myers, 2009). One such psychosocial factor suggested by previous research is the early experience of racial discrimination. Racial discrimination that is perceived during childhood has been associated (cross-sectionally and prospectively) with an array of negative developmental consequences, including increased substance use (Gibbons et al. 2007; Gibbons et al., in press; Guthrie, Young, Williams, Boyd, & Kintner, 2002), delinquency (Prelow, DanoffBurg, Swenson, & Pulgiano, 2004; Simons, Chen, Stewart, & Brody, 2003,), diminished academic achievement (Eccles, Wong, & Peck, 2006; O’Hara, Gibbons, Weng, Gerrard, & Simons, 2011), and poor mental health (Cooper, McLoyd, Wood, & Hardaway, 2008; Greene, Way, & Pahl, 2006). The general theoretical explanation for these relations is that discriminatory experiences are very stressful events for African Americans (Clark, Anderson, Clark, & Williams, 1999; Sanders-Phillips, Settles-Reaves, Walker, & Brownlow, 2009), and the cognitive, emotional, and behavioral responses to this stress promote maladaptive behaviors (Pascoe & Richman, 2009; Williams & Mohammed, 2009). Discrimination is believed to have a particularly strong impact in early adolescence (Gibbons et al., 2007; Simons et al., 2002), since during this period, important transitions in the development of the self-concept and ethnic identity (French, Seidman, Allen, & Aber, 2006; Harter, 1999) are happening in concurrence with an increasing awareness of discrimination (Quintana, 1998). Given that risky sexual behavior is frequently associated with substance use and other problematic behaviors (Feldstein & Miller, 2006; Shrier, Emans, Woods, & DuRant, 1997) it is reasonable to expect that the negative influence of discrimination extends to risky sexual behavior. Indeed, one cross-sectional study (Stevens-Watkins, Brown-Wright, & Tyler, 2010) found that after controlling for SES and age at first intercourse, African American high school students who reported more discrimination also reported a greater number of sexual partners. However, research on early-experienced discrimination has not yet investigated the impact of such discrimination on risky sexual behavior prospectively. Furthermore, the mechanisms of this relation remain unclear: If the sexual behaviors that put young African Americans at risk for STIs are in part influenced by prior experience with discrimination, then it is important to understand both how this effect occurs, and how it can be attenuated. The present study was therefore designed to explore the potential factors involved in an anticipated prospective relation between early perceived racial discrimination and subsequent risky sexual behavior among a diverse sample of African American youths.1

Folate Deficiency Induces a Cell Cycle-Specific Apoptosis in HepG2 Cells

Abstract: The human hepatoma HepG2 cell line was chosen as a representative of solid tissue-derived cell systems in which folate metabolism and apoptosis induction have not been thoroughly investigated. HepG2 cells were cultivated in the control or folate-deficient media (control media lacking of folate, glycine, thymidine and hypoxanthine) for 4 wk. This resulted in a decrease in intracellular folate levels to 32% of the control within 1 wk, which was followed by growth arrest and greater cell death rates. These disturbances of folate deficiency coincided with apoptotic induction, as characteristically shown by nucleosomal DNA fragmentation of 180-200 base pair multimers, nuclear chromatin condensation and positive terminal transferase-mediated dUTP nick end labeling assay. Apoptosis coincided with an accumulation of cells in S-phase, a subsequent G2/M phase block and a significant increase in mean protein content as evaluated by flow cytometric analyses employing a double-staining method. The growth and cell cycle arrest under folate-deficient conditions was independent of a change of p53 expression as measured by an enzyme-linked immunosorbent assay. Supplementation of 2 micromol/L folate normalized cell cycles and diminished DNA fragmentation. Taken together, these data indicate that HepG2 cells cultivated in folate-deficient medium have a low folate concentration, decreased growth and viability, and increased apoptotic propensity. This occurrence of apoptosis was associated with a cell cycle-specific mechanism and independent of p53-mediated pathway.