Depression promotes breast cancer progression by regulating amino acid neurotransmitter metabolism and gut microbial disturbance.

INTRODUCTION: Breast cancer (BC) is the most prevalent type of cancer and has the highest mortality among women worldwide. BC patients have a high risk of depression, which has been recognized as an independent factor in the progression of BC. However, the potential mechanism has not been clearly demonstrated. METHODS: To explore the correlation and mechanism between depression and BC progression, we induced depression and tumor in BC mouse models. Depression was induced via chronic unpredictable mild stress (CUMS) and chronic restraint stress (CRS). Amino acid (AA) neurotransmitter-targeted metabonomics and gut microbiota 16S rDNA gene sequencing were employed in the mouse model after evaluation with behavioral tests and pathological analysis. RESULTS: The tumors in cancer-depression (CD) mice grew faster than those in cancer (CA) mice, and lung metastasis was observed in CD mice. Metabonomics revealed that the neurotransmitters and plasma AAs in CD mice were dysregulated, namely the tyrosine and tryptophan pathways and monoamine neurotransmitters in the brain. Gut microbiota analysis displayed an increased ratio of Firmicutes/Bacteroides. In detail, the abundance of f_Lachnospiraceae and s_Lachnospiraceae increased, whereas the abundance of o_Bacteroidales and s_Bacteroides_caecimuris decreased. Moreover, the gut microbiota was more closely associated with AA neurotransmitters than with plasma AA. CONCLUSION: Depression promoted the progression of BC by modulating the abundance of s_Lachnospiraceae and s_Bacteroides_caecimuris, which affected the metabolism of monoamine neurotransmitters in the brain and AA in the blood.

HIV self-test performance evaluation among priority populations in rural Mozambique: Results from a community-based observational study

Background In 2021, Mozambique initiated community-based oral HIV self-testing (HIVST) to increase testing access and uptake among priority groups, including adult males, adolescents, and young adults. Within an HIVST pilot project, we conducted a performance evaluation assessing participants' ability to successfully conduct HIVST procedures and interpret results. Methods A cross-sectional study was performed between February-March 2021 among employees, students (18­24 years of age), and community members, using convenience sampling, in two rural districts of Zambézia Province, Mozambique. We quantified how well untrained users performed procedures for the oral HIVST (Oraquick®) through direct observation using a structured checklist, from which we calculated an HIVST usability index (scores ranging 0­100%). Additionally, participants interpreted three previously processed anonymous HIVST results. False reactive and false non-reactive interpretation results were presented as proportions. Bivariate analysis was conducted using Chi-square and Fisher exact tests. Results A total of 312 persons participated (131[42%] community members, 71[23%] students, 110[35%] employees); 239 (77%) were male; the mean age was 28 years (standard deviation 10). Average usability index scores were 80% among employees, 86% among students, and 77% among community members. Main procedural errors observed included "incorrect tube positioning" (49%), "incorrect specimen collection" (43%), and "improper waiting time for result interpretation" (42%). From the presented anonymous HIVST results, 75% (n = 234) correctly interpreted all three results, while 9 (3%) of study participants failed to correctly interpret any results. Overall, 36 (12%) gave a false non-reactive result interpretation, 21 (7%) a false reactive result interpretation, and 14 (4%) gave both false non-reactive and false reactive result interpretations. Community members generally had lower performance. Conclusions Despite some observed testing procedural errors, most users could successfully perform an HIVST. Educational sessions at strategic places (e.g., schools, workplaces), and support via social media and hotlines, may improve HIVST performance quality, reducing the risk of incorrect interpretation.