Studies Recruiting Only Men

The goal of this clinical trial is to test the efficacy of a mobile app, Combine, to increase the uptake of HIV and STI testing and pre-exposure prophylaxis (PrEP) over 24 months and to assess the effects of different implementation strategies on intervention maintenance among GBMSM in rural southern United States. The main aims of the study are:

* To assess the relative effects of three treatment conditions on gains in engagement in HIV prevention compared to a modified standard of care control condition * Measure and assess secondary factors affecting app implementation * Refine implementation strategies and coordinate with potential funders Participants will download an HIV prevention smartphone app and be randomly assigned to one of four groups: * Control: App access only * Self-testing: App access + ability to order HIV and STI self-test kits * Motivational interview: App access + motivational interview to develop plans to use app effectively. * Self-testing + motivational interview: App access + ability to order HIV and STI self-test kits + motivational interview to develop plans to use app effectively.

Researchers will compare each of the latter three groups to the control condition to see if HIV and STI testing increase in these groups

This study seeks to develop and pilot test a theory-based, integrated technology and counseling intervention to improve ART adherence among sexual and gender minority (SGM) young people living with HIV (ages 18-24) in Rio de Janeiro, Brazil. The intervention aims to improve social support, self-efficacy for taking ART, and teach skills for problem-solving barriers to promote better adherence.

The purpose of this clinical trial is to evaluate and test a newly developed gender-affirming intervention that addresses the dual and interconnected risks of HIV and intimate partner victimization (IPV) among transgender women (TW). The main questions it aims to answer are: (1) will the study intervention reduce HIV risk within the context of IPV and related risk factors (e.g., substance use and PTSD); (2) will STARS improve primary prevention behaviors, such as condom use, pre-exposure prophylaxis (PrEP) use, and repeat HIV testing; and (3) what are the mechanisms of change relevant to the theoretical foundations of the intervention, including gender affirmation, empowerment, and self-efficacy. The findings from this study will provide the necessary groundwork to examine the efficacy of this combined HIV-IPV intervention in a future, large-scale clinical trial.

There are several components to this research study:

* First, participants will be asked to complete a series of screening interviews/questionnaires to determine eligibility, including completing a HIV test. * If eligible, participants will then take part in a 2-3 hour baseline assessment consisting of both interviewer administered questionnaires as well as self-administered surveys. * Participants will then be randomly assigned to one of two treatment conditions: (1) a newly developed gender affirming intervention, known as Program STARS (Supporting Trans Affirmation, relationships, and Sex) or (2) a time-matched, attention-controlled program that offers free training in relaxation and stress reduction techniques (a.k.a., the comparison group). Both interventions offer unique components and the researchers do not yet know the impact the programs may have on participants' overall well-being. * Participants randomized to Project STARS, will be invited to complete a semi-structured exit interview (lasting 60-90 min.) after the completion of the program. * This clinical trial has three follow-up assessments: (1) post-intervention (i.e., after the peer-counseling programs are complete); (2) at 4-months follow-up; and (3) at 6-months follow-up. The follow-up assessments are structured the same way as the baseline assessment and are estimated to take around 1-2 hours.

The total study involvement for this clinical trial is estimated to take approximately 10 to 12 hours over the course of six months.

This study will evaluate the impact of U=U messaging and counseling on gaps in the HIV care cascade for men, including testing uptake and ART initiation (Aim 1), achieving viral suppression and retention in care (Aim 2) in two provinces in South Africa. The U=U message communicates the compelling idea that PLHIV who take ART and have an undetectable viral load (\<200 copies/mL) cannot sexually transmit HIV. Additionally, the investigators will conduct a multi-method evaluation to inform future implementation of U=U messaging interventions (Aim 3).

The goal of this study is to develop and pilot test technology-based interventions to promote Pre-exposure Prophylaxis (PrEP) uptake and adherence among Thai young men who have sex with men (YMSM).

This phase I trial studies if positron emission tomography (PET) imaging using 11C-YJH08 can be useful for detecting certain cell receptor expression in tumor cells in patients with cancer that has spread to other parts of the body (metastatic). 11C-YJH08 is a small-molecule radiotracer that binds to receptors on cells (glucocorticoid receptor) so that they show up better on the PET scan. Systemic therapy (including enzalutamide) can cause more glucocorticoid receptors to be produced in tumor cells, which can make the tumor cells resist hormone therapies. If researchers can find a better way to detect whether glucocorticoid receptors are increasing during therapy, it may lead to more successful therapies using glucocorticoid receptor antagonists.

The aim of the present study is to assess the availability of cannabinoid receptors (CB1R) in the human brain. CB1R are present in everyone's brain, regardless of whether or not someone has used cannabis. The investigators will image brain cannabinoid receptors using Positron Emission Tomography (PET) imaging and the radioligand OMAR, in healthy individuals and several conditions including 1) cannabis use disorders, 2) psychotic disorders, 3) prodrome of psychotic illness and 4) individuals with a family history of alcoholism, 5) Post-Traumatic Stress Disorder 6) Opioid Use Disorder using the PET imaging agent or radiotracer, \[11C\]OMAR. This will allow us to characterize the number and distribution of CB1R in these conditions. It is likely that the list of conditions will be expanded after the collection of pilot data and as new data on cannabinoids receptor function and psychiatric disorders becomes available.

Those in the cannabis us disorder arm of the study will have a PET scan on at least three occasions: once while smoking as usual, once after 48-hours of abstinence from cannabis, and a final time after 4 weeks of abstinence. Additional scans may be conducted within the 4 weeks and the last scan may be conducted well beyond 4 weeks. Similarly, while most schizophrenia patients may get scanned just once, a subgroup of patients may get scanned more than once. For example to tease out the effects of medications, unmedicated patients may get scanned while unmedicated and again after treatment with antipsychotic medications. Similarly prodromes may get scanned while in the prodromal stage off medications, on medications and after conversion to schizophrenia.