Light chain 2 is a Tctex-type related axonemal dynein light chain that regulates directional ciliary motility in Trypanosoma brucei.

Flagellar motility is essential for the cell morphology, viability, and virulence of pathogenic kinetoplastids. Trypanosoma brucei flagella beat with a bending wave that propagates from the flagellum's tip to its base, rather than base-to-tip as in other eukaryotes. Thousands of dynein motor proteins coordinate their activity to drive ciliary bending wave propagation. Dynein-associated light and intermediate chains regulate the biophysical mechanisms of axonemal dynein. Tctex-type outer arm dynein light chain 2 (LC2) regulates flagellar bending wave propagation direction, amplitude, and frequency in Chlamydomonas reinhardtii. However, the role of Tctex-type light chains in regulating T. brucei motility is unknown. Here, we used a combination of bioinformatics, in-situ molecular tagging, and immunofluorescence microscopy to identify a Tctex-type light chain in the procyclic form of T. brucei (TbLC2). We knocked down TbLC2 expression using RNAi in both wild-type and FLAM3, a flagellar attachment zone protein, knockdown cells and quantified TbLC2's effects on trypanosome cell biology and biophysics. We found that TbLC2 knockdown reduced the directional persistence of trypanosome cell swimming, induced an asymmetric ciliary bending waveform, modulated the bias between the base-to-tip and tip-to-base beating modes, and increased the beating frequency. Together, our findings are consistent with a model of TbLC2 as a down-regulator of axonemal dynein activity that stabilizes the forward tip-to-base beating ciliary waveform characteristic of trypanosome cells. Our work sheds light on axonemal dynein regulation mechanisms that contribute to pathogenic kinetoplastids' unique tip-to-base ciliary beating nature and how those mechanisms underlie dynein-driven ciliary motility more generally.

What is needed for eating disorder prevention for transgender and gender diverse young adults? Findings from asynchronous online focus groups.

Transgender and gender diverse (TGD) young adults face higher risk of eating disorder (ED) symptoms than cisgender peers. Evidence-based ED prevention programs exist but must be adapted to meet the needs of diverse TGD populations. We conducted eight asynchronous online focus groups in 2019 with 66 ethnically and gender diverse TGD young adults (18-30 years) living in the United States. Participants were recruited online; groups took place over four consecutive days. We conducted inductive thematic analysis of participant responses to three prompts about ED prevention needs and advice for program developers. Findings fell into three domains. In Domain 1: Developing Program Content, themes included (1.1) need to address multiple dimensions of gender; (1.2) intersectional representation matters; (1.3) limitations of ED research; (1.4) being responsive to trauma. Domain 2: Program Delivery Considerations, included preferences for (2.1) group composition, (2.2) intervention modality, and (2.3) program leadership. Domain 3: Cultivating Affirming Spaces included themes addressing the need for programs to (3.1) create judgment-free environments and (3.2) center lived experience. TGD young adults in this study described a range of needs and recommendations for ED prevention content and delivery, with relevance to clinicians, program designers, and ED prevention advocates.

Structure-function relationships of TMJ lateral capsule-ligament complex.

The human temporomandibular joint (TMJ) lateral capsule ligament (LCL) complex is debated as a fibrous capsule with distinct ligaments or ligamentous thickening, necessitating further evaluation of the complex and its role in TMJ anatomy and mechanics. This study explores the ultrastructural arrangement, biomechanical tensile properties, and biochemical composition of the human LCL complex including region-specific differences to explore the presence of a distinct temporomandibular ligament and sex-specific differences to inform evaluations of potential etiological mechanisms. LCL complex ultrastructural arrangement, biomechanical properties, and biochemical composition were determined using cadaveric samples. Statistical modeling assessed sex- and region-specific effects on LCL complex tissue properties. Collagen fiber coherency, collagen fiber bundle size, and elastin fiber count did not differ between sexes, but females trended higher in elastin fiber count. LCL complex water and sGAG content did not differ between sexes or regions, but collagen content was higher in the anterior region (311.0 ± 185.6 µg/mg) compared to the posterior region (221.0 ± 124.9 µg/mg) (p = 0.045) across sexes and in males (339.6 ± 170.6 µg/mg) compared to females (204.5 ± 130.7 µg/mg) (p = 0.006) across regions. Anterior failure stress (1.1 ± 0.7 MPa) was larger than posterior failure stress (0.6 ± 0.4 MPa) (p = 0.024). Regional differences confirm the presence of a mechanically and compositionally distinct temporomandibular ligament. Baseline sex-specific differences are critical for etiological investigations of sex disparities in TMJ disorders. These results have important biomechanical and clinical ramifications, providing critical baseline tissue material properties, informing the development of TMJ musculoskeletal models, and identifying new areas for etiologic investigations for temporomandibular disorders.

Asynchronous Online Focus Groups for Health Research: Case Study and Lessons Learned.

Increasingly, social life-and accordingly, social research-is conducted in online environments. Asynchronous online focus groups (AOFGs) have emerged as an important tool to conduct remote research with geographically diverse populations. However, there remain few systematic accounts of AOFG methods to guide researchers' decision-making in designing and implementing studies. This paper seeks to address this gap by describing a recent study on body image and health among transgender and gender diverse (TGD) young adults. In this study, eight AOFGs were conducted in August-October 2019 with 66 TGD young adults residing in 25 U.S. states. Each AOFG lasted four consecutive days with two prompts posted by moderators per day. Overall, participant satisfaction with AOFGs was high: 98% reported their experience was excellent, very good, or good and 95% would be somewhat or very likely to sign up for another AOFG. This example is used to illustrate key methodological decision-points, acceptability of the method to participants, and lessons learned. The goal of this paper is to encourage other researchers, particularly health researchers, to consider using AOFGs and to engage with the method's strengths and limitations in order to develop new opportunities for online technologies to enrich the field of qualitative health research.

Eating disorder screening and treatment experiences in transgender and gender diverse young adults.

Transgender and gender diverse (TGD) young adults have elevated risk for disordered eating, unhealthy weight control behaviors, and eating disorders (EDs). Little is known about TGD young adult experiences with ED screening and treatment; this qualitative study aimed to address this gap. This study used data from eight asynchronous online focus groups, a dynamic online bulletin board method (N = 66). Participants posted responses to moderator-posed questions over a 4-day period. Participants were TGD young adults ages 18-30 years old, were recruited using social media and outreach to community organizations, and resided in 25 US states. We conducted inductive thematic analysis of all focus group excerpts that described experiences with ED screening or treatment (n = 32). Participants were of diverse gender identities (25% transgender woman, 41% transgender man, 28% non-binary, 6% another gender) and racial/ethnic identities (62% White, 13% Latinx, 13% Multiracial, 6% Asian, 6% Black). Three major themes emerged from the analysis: (1) Barriers to ED screening/treatment; (2) Complexity of the relationship between EDs and gender dysphoria; (3) Need for provider education in gender affirming care practices for ED screening and treatment. Results indicate an ongoing need for gender affirming care for TGD young adults in ED screening and treatment. Health care systems must address barriers to screening and treatment for TGD young adults, including enhancing understanding of the intersection of gender dysphoria and eating disorders as well as improvements in health care provider training.

Measurement and construct validity of the Eating Disorder Examination Questionnaire Short Form in a transgender and gender diverse community sample.

This study evaluated the measurement and construct validity of the Eating Disorder Examination Questionnaire Short Form (EDE-QS) in a transgender and gender diverse sample. Participants who self-identified as transgender and gender diverse (N = 71) completed self-report measures of demographics, gender-related experiences, and disordered eating/body image. Analyses comprised evaluation of EDE-QS internal consistency, convergent validity, and specificity for disordered eating. The EDE-QS demonstrated strong internal consistency in the full sample, in participants with and without suspected eating disorders, and in each gender identity group; and correlated significantly with indices of disordered eating and body image. The full scale and each item significantly differentiated between participants with and without suspected eating disorders. This study provides initial evidence for good measurement and construct validity of the EDE-QS as applied to transgender and gender diverse individuals. Findings offer the EDE-QS as a promising, brief tool for screening and/or population-based research related to disordered eating in this high-risk, yet underserved population. (PsycInfo Database Record (c) 2021 APA, all rights reserved).