Preferences for and Experiences of an HIV-Prevention Mobile App Designed for Transmasculine People: Pilot Feasibility Trial and Qualitative Investigation

BACKGROUND

Transmasculine people are at risk for HIV; yet few HIV prevention interventions have been developed for this population. We adapted an existing HIV prevention smartphone app for cisgender men who have sex with men to meet the sexual health needs of transmasculine people.

OBJECTIVE

This study aims to assess the acceptability of the adapted app, Transpire, among transmasculine people living in Atlanta, Georgia, and Washington, DC, via in-depth interviews of participants in a pilot feasibility trial.

METHODS

Participants used the Transpire app for 3 months as part of a pilot study of the app. Eligible participants were aged 18-34 years. There were no eligibility criteria with respect to race and ethnicity, and most participants were non-Hispanic White. At the end of the follow-up, participants were invited to participate in web-based in-depth interviews to discuss their experiences using the app and feedback on design and content. Interviews were transcribed and coded using a constant comparative approach. Three main themes were identified: sexual behavior, app experiences and feedback, and pre-exposure prophylaxis.

RESULTS

Overall, participants found the app acceptable and thought that it would be a useful tool for themselves and their peers. Participants reported appreciating having a comprehensive information source available to them on their phones and reported learning more about HIV, sexually transmitted infections, and pre-exposure prophylaxis via the app. They also reported appreciating the inclusive language that was used throughout the app. Although the app included some resources on mental health and substance use, participants reported that they would have appreciated more resources and information in these areas as well as more comprehensive information about other health concerns, including hormone therapy. Representative quotes are presented for each of the identified themes.

CONCLUSIONS

There is a desire to have greater access to reliable sexual health information among transmasculine people. Mobile apps like Transpire are an acceptable intervention to increase access to this information and other resources. More evidence is needed, however, from more racially and ethnically diverse samples of transmasculine people.

Human scFv antibody fragments specific for the epithelial tumour marker MUC-1, selected by phage display on living cells

New anti-cancer agents are being developed that specifically recognise tumour cells. Recognition is dependent upon the enhanced expression of antigenic determinants on the surface of tumour cells. The tumour exposure and the extracellular accessibility of the mucin MUC-1 make this marker a suitable target for tumour diagnosis and therapy. We isolated and characterised six human scFv antibody fragments that bound to the MUC-1 core protein, by selecting a large naive human phage display library directly on a MUC-1-expressing breast carcinoma cell line. Their binding characteristics have been studied by ELISA, FACS and indirect immunofluorescence. The human scFv antibody fragments were specific for the tandem repeat region of MUC-1 and their binding is inhibited by soluble antigen. Four human scFv antibody fragments (M2, M3, M8, M12) recognised the hydrophilic PDTRP region of the MUC-1 core protein, which is thought to be an immunodominant region. The human scFv antibody fragments were stable in human serum at 37 degrees C and retained their binding specificity. For imaging or targeting to tumours over-expressing MUC-1, it might be feasible to use these human scFv, or multivalent derivatives, as vehicles to deliver anti-cancer agents.

Regulated expression of the Streptococcus mutans dlt genes correlates with intracellular polysaccharide accumulation

Intracellular polysaccharides (IPS) are glycogen-like storage polymers which contribute significantly to Streptococcus mutans-induced cariogenesis. We previously identified and cloned a locus from the S. mutans chromosome which is required for the accumulation of IPS. Sequencing of this locus revealed at least four contiguous open reading frames, all of which are preceded by a common promoter region and are transcribed in the same direction. Analysis of the amino acid sequence deduced from the first of these open reading frames (ORF1) revealed domains which are highly conserved among D-alanine-activating enzymes (DltA) in Lactobacillus rhamnosus (formerly Lactobacillus casei) and Bacillus subtilis. The deduced amino acid sequences derived from ORF2, -3, and -4 also exhibit extensive similarity to DltB, -C, and -D, respectively, in these microorganisms. However, Southern hybridization experiments indicate that this operon maps to a locus on the S. mutans chromosome which is separate from the glgP, glgA, and glgD genes, whose products are known mediators of bacterial IPS accumulation. We therefore assigned a new dlt designation to the locus which we had formerly called glg. We maintain that the dlt genes are involved in S. mutans IPS accumulation, however, since they complement a mutation in trans which otherwise renders S. mutans IPS deficient. In this study, we found that expression of the S. mutans dlt genes is growth phase dependent and is modulated by carbohydrates internalized via the phosphoenolpyruvate phosphotransferase system (PTS). We demonstrated that the S. mutans dlt genes are expressed constitutively when non-PTS sugars are provided as the sole source of carbohydrate. Consistent with a role for the PTS in dlt expression is a similar constitutive expression of the dlt genes in an S. mutans PTS mutant grown in a chemically defined medium supplemented with glucose. In summary, these findings support a novel role for the dlt gene products in S. mutans IPS accumulation and suggest that dlt expression in this oral pathogen is subject to complex mechanisms of control imposed by growth phase, dietary carbohydrate, and other factors present in the plaque environment.

The AAUAAA sequence is required both for cleavage and for polyadenylation of simian virus 40 pre-mRNA in vitro

The sequence AAUAAA is found near the polyadenylation site of eucaryotic mRNAs. This sequence is required for accurate and efficient cleavage and polyadenylation of pre-mRNAs in vivo. In this study we show that synthetic simian virus 40 late pre-mRNAs are cleaved and polyadenylated in vitro in a HeLa cell nuclear extract, and that cleavage in vitro is abolished by each of four different single-base changes in AAUAAA. In this same extract, precleaved RNAs (RNAs with 3' termini at the polyadenylation site) are efficiently polyadenylated. This in vitro polyadenylation reaction also requires the AAUAAA sequence.

Cloning and characterization of a mRNA-encoding rat preprosomatostatin

An undecanucleotide extended hybridization probe has been used to screen a rat medullary thyroid carcinoma cDNA library for clones which contain preprosomatostatin sequences. The nucleotide sequence encoding rat preprosomatostatin is reported. The sequence of cDNA contains 67 nucleotides in the 3'-noncoding region, 84 nucleotides in the 5'-untranslated region, and 458 bases corresponding to the coding region. The mRNA codes for a somatostatin precursor 116 amino acids in length (Mr = 12,773). The preprosomatostatin has a sequence of hydrophobic amino acids at the NH2 terminus, followed by a peptide of approximately 78 residues, which precedes somatostatin-14. The amino acid sequences of rat and human preprosomatostatin (Shen, L. P., Pictet, R. L., and Rutter, W. J. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 4575-4579) differ by only 4 amino acid residues. Translation of rat poly(A) RNA in a rabbit reticulocyte cell-free system followed by immunoprecipitation with antisera directed against somatostatin-14 demonstrated the synthesis of a single protein having a molecular weight of 15,000. Two proteins having molecular weights of 14,000 and 15,000 are immunoprecipitated from a wheat germ cell-free translation mixture. Northern analysis of the somatostatin mRNA indicated that it is approximately 850 nucleotides in length. Analysis of several medullary thyroid carcinomas demonstrated that one tumor, designated WF, had immunoreactive somatostatin-14 in concentrations of 350 ng of somatostatin-14/mg of protein and somatostatin mRNA that represented 10% of the cellular poly(A) RNA. Cell lines derived from this tumor may provide an attractive system to investigate the regulation of somatostatin gene expression.