Three promoters have been identified as having potentially important regulatory roles in governing expression of the fla/che operon and of sigD , a gene that lies near the 3′ end of the operon. Two of these promoters, fla/che P A and P D-3 , lie upstream of the >26-kb fla/che operon. The third promoter, P sigD , lies within the operon, immediately upstream of sigD. fla/che P A , transcribed by Eς A , lies ≥24 kb upstream of sigD and appears to be largely responsible for sigD expression. P D-3 , transcribed by Eς D , has been proposed to participate in an autoregulatory positive feedback loop. P sigD , a minor ς A -dependent promoter, has been implicated as essential for normal expression of the fla/che operon. We tested the proposed functions of these promoters in experiments that utilized strains that bear chromosomal deletions of fla/che P A , P D-3 , or P sigD . Our analysis of these strains indicates that fla/che P A is absolutely essential for motility, that P D-3 does not function in positive feedback regulation of sigD expression, and that P sigD is not essential for normal fla/che expression. Further, our results suggest that an additional promoter(s) contributes to sigD expression.
African American women experience faster telomere shortening (i.e., cellular aging) compared with other racial–gender groups. Prior research demonstrates that race and gender interact to influence culturally specific norms for responding to socially-relevant stress and other stress-coping processes, which may affect healthy aging. Data are from African American Women’s Heart & Health Study participants who consented to DNA extraction (n = 140). Superwoman Schema (SWS) was measured using 5 validated subscales: presenting strength, emotion suppression, resisting vulnerability, motivation to succeed, and obligation to help others. Racial identity was measured using 3 subscales from the Multidimensional Inventory of Black Identity: racial centrality, private regard, and public regard. Relative telomere length (rTL) was measured using DNA extracted from blood samples. Path analysis tested associations and interactions between SWS and racial identity dimensions with rTL. For SWS, higher resistance to being vulnerable predicted longer telomeres. For racial identity, high private regard predicted longer telomeres while high public regard predicted shorter telomeres. Interactions were found between public regard and 2 SWS dimensions: among women with high public regard, emotion suppression (β = 0.20, p < .05) and motivation to succeed (β = 0.18, p < .05) were associated with longer rTL. The interaction between high centrality and emotion suppression predicted shorter rTL (β = −0.17, p < .05). Culturally specific responses to gendered racism and racial identity, developed early in life and shaped over the life course, are important psychosocial determinants of cellular aging among African American women.
We offer and test a brief psychosocial intervention, Speaking Truth to EmPower (STEP), designed to protect underrepresented minorities’ (URMs) intellectual performance and safety in science, technology, engineering, and math (STEM). STEP takes a ‘knowledge as power’ approach by: (a) providing a tutorial on stereotype threat (i.e., a social contextual phenomenon, implicated in underperformance and early exit) and (b) encouraging URMs to use lived experiences for generating be-prepared coping strategies. Participants were 670 STEM undergraduates [URMs (Black/African American and Latina/o) and non-URMs (White/European American and Asian/Asian American)]. STEP protected URMs’ abstract reasoning and class grades (adjusted for grade point average [GPA]) as well as decreased URMs’ worries about confirming ethnic/racial stereotypes. STEP’s two-pronged approach—explicating the effects of structural ‘isms’ while harnessing URMs’ existing assets—shows promise in increasing diversification and equity in STEM.
The under-representation of ethnic minority participants, who are more likely to be socially disadvantaged in biomedical research, limits generalizability of results and reductions in health disparities. To facilitate investigations of how social disadvantage “gets under the skin,” this pilot study evaluated low-intensity methods for collecting hair and saliva samples from multiethnic breast cancer survivors (N = 70) and analysis of biomarkers of chronic stress (cortisol levels) and biological age (telomere length). Methods allowed for easy self-collection of hair (for cortisol) and saliva (for telomere lengths) samples that were highly stable for shipment and long-term storage. Measuring cortisol in hair as a biomarker of chronic stress was found to overcome many of the limitations of salivary cortisol measurements, and the coefficient of variation obtained using an ELISA-based approach to measure cortisol was within acceptable standards (16%). Telomere length measurements obtained using a qPCR approach had a coefficient of variation of <10% when the DNA extracted from the saliva biospecimens was of sufficient quantity and quality (84%). The overall response rate was 47%; rates were 32% for African-Americans, 39% for Latinas, 40% for Asians, and 82% for non-Latina Whites. Self-collection of hair and saliva overcame cultural and logistical barriers associated with collection of blood. Results support the use of these biospecimen collection and analysis methods among ethnically diverse and disadvantaged populations to identify biopsychosocial pathways of health disparities. Our tools should stimulate research to better understand how social disadvantage “gets under the skin” and increase participation of ethnic minorities in biomedical research.
1 March 2020 in Cancer Epidemiology, Biomarkers & Prevention
Background: Latinos are underrepresented in biomedical research, particularly biomarker research, yet they constitute the nation's largest ethnic/racial minority. Optimal methods for obtaining biospecimens for biomarker research among Latinos need to be identified. To minimize barriers and enhance participation, this study developed and tested tailored strategies for collecting biomarkers of chronic stress and premature aging among Spanish-speaking Latina breast cancer survivors. Methods: This study used a community-based participatory approach and selected hair and saliva as noninvasive biospecimens to assess telomere length, the cortisol awakening response (CAR), and hair cortisol concentration. We developed bilingual multimedia instructional materials, and community health workers assisted in collections. Telephone surveys assessed willingness to participate in future studies, barriers to sample collection, and recommendations for improving the strategies. Results: A total of 103 participants were recruited over 18 months from two rural sites in California, and 88 were retained at 6-month follow-up. At baseline, rates of donating salivary DNA for telomere length measurement, saliva for CAR analysis, and hair for cortisol concentration were 98%, 89%, and 52%, respectively. At follow-up, rates were 83%, 76%, and 55%, respectively. The majority of participants reported being very willing to provide hair (72%) or saliva (74%) for future studies. Conclusions: Our results support the feasibility of including minorities in biomedical research. We report excellent rates of saliva collection when community partners are engaged in the process, and when patient-centered and culturally tailored recruitment methods are implemented. Impact: The development of methods to facilitate the inclusion of minorities in biomedical research is critical to eliminate racial/ethnic health disparities.
The underrepresentation of minority students in the sciences constrains innovation and productivity in the U.S. The SF BUILD project mission is to remove barriers to diversity by taking a “fix the institution” approach rather than a “fix the student” one. SF BUILD is transforming education, research, training, and mentoring at San Francisco State University, a premiere public university that primarily serves undergraduates and ethnic minority students. It boasts a large number of faculty members from underrepresented groups (URGs), including many of the project leaders. These leaders collaborate with faculty at the University of California San Francisco (UCSF), a world-class medical research institution, to implement SF BUILD. Together, the campus partners are committed to creating intellectually safe and affirming environments grounded in the Signaling Affirmation for Equity (SAFE) model, which is based on robust psychosocial evidence on stereotype threat and its consequences. The SAFE model dictates a multilevel approach to increasing intent to pursue a biomedical career, persistence in STEM fields, and productivity (e.g. publications, presentations, and grants) by implementing transformative activities at the institutional, faculty, and student levels. These activities (1) increase knowledge of the stereotype threat phenomenon; (2) affirm communal and altruistic goals of students and faculty to “give back” to their communities in classrooms and research activities; and (3) establish communities of students, faculty and administrators as “agents of change.” Agents of change are persons committed to establishing and maintaining SAFE environments. In this way, SF BUILD advances the national capacity to address biomedical questions relevant to communities of color by enabling full representation in science. This chapter describes the theoretical and historical context that drive the activities, research and evaluation of the SF BUILD project, and highlights attributes that other institutions can use for institutional change. While this paper is grounded in psychosocial theory, it also provides practical solutions for broadening participation.