Transcriptome-wide association analysis identifies candidate susceptibility genes for prostate-specific antigen levels in men without prostate cancer.

Deciphering the genetic basis of prostate-specific antigen (PSA) levels may improve their utility for prostate cancer (PCa) screening. Using genome-wide association study (GWAS) summary statistics from 95,768 PCa-free men, we conducted a transcriptome-wide association study (TWAS) to examine impacts of genetically predicted gene expression on PSA. Analyses identified 41 statistically significant (p < 0.05/12,192 = 4.10 × 10-6) associations in whole blood and 39 statistically significant (p < 0.05/13,844 = 3.61 × 10-6) associations in prostate tissue, with 18 genes associated in both tissues. Cross-tissue analyses identified 155 statistically significantly (p < 0.05/22,249 = 2.25 × 10-6) genes. Out of 173 unique PSA-associated genes across analyses, we replicated 151 (87.3%) in a TWAS of 209,318 PCa-free individuals from the Million Veteran Program. Based on conditional analyses, we found 20 genes (11 single tissue, nine cross-tissue) that were associated with PSA levels in the discovery TWAS that were not attributable to a lead variant from a GWAS. Ten of these 20 genes replicated, and two of the replicated genes had colocalization probability of >0.5: CCNA2 and HIST1H2BN. Six of the 20 identified genes are not known to impact PCa risk. Fine-mapping based on whole blood and prostate tissue revealed five protein-coding genes with evidence of causal relationships with PSA levels. Of these five genes, four exhibited evidence of colocalization and one was conditionally independent of previous GWAS findings. These results yield hypotheses that should be further explored to improve understanding of genetic factors underlying PSA levels.

Transcriptome-Wide Association Analysis Identifies Novel Candidate Susceptibility Genes for Prostate-Specific Antigen Levels in Men Without Prostate Cancer.

Deciphering the genetic basis of prostate-specific antigen (PSA) levels may improve their utility to screen for prostate cancer (PCa). We thus conducted a transcriptome-wide association study (TWAS) of PSA levels using genome-wide summary statistics from 95,768 PCa-free men, the MetaXcan framework, and gene prediction models trained in Genotype-Tissue Expression (GTEx) project data. Tissue-specific analyses identified 41 statistically significant (p < 0.05/12,192 = 4.10e-6) associations in whole blood and 39 statistically significant (p < 0.05/13,844 = 3.61e-6) associations in prostate tissue, with 18 genes associated in both tissues. Cross-tissue analyses that combined associations across 45 tissues identified 155 genes that were statistically significantly (p < 0.05/22,249 = 2.25e-6) associated with PSA levels. Based on conditional analyses that assessed whether TWAS associations were attributable to a lead GWAS variant, we found 20 novel genes (11 single-tissue, 9 cross-tissue) that were associated with PSA levels in the TWAS. Of these novel genes, five showed evidence of colocalization (colocalization probability > 0.5): EXOSC9, CCNA2, HIST1H2BN, RP11-182L21.6, and RP11-327J17.2. Six of the 20 novel genes are not known to impact PCa risk. These findings yield new hypotheses for genetic factors underlying PSA levels that should be further explored toward improving our understanding of PSA biology.

Peer Navigation to Support Transgender Women's Engagement in HIV Care: Findings from the Trans Amigas Pilot Trial in São Paulo, Brazil.

Trans women living with HIV (TWH) have suboptimal HIV care engagement. We pilot tested Trans Amigas, a theory-based, trans-specific peer navigation (PN) intervention to address barriers to care in São Paulo, Brazil. TWH were randomized to the PN intervention (n = 75) or control (n = 38) condition. Control participants were referred to trans-friendly HIV care. Intervention participants were assigned a navigator who conducted nine in-person one-on-one sessions and bi-weekly phone or text check-ins to help participants overcome barriers to care and work towards gender affirmation and healthcare goals. We followed participants for 9 months to determine intervention feasibility, acceptability, and preliminary efficacy in improving retention in care. Analyses were intention to treat (ITT). Intervention acceptability was high: at end line, 85.2% of PN participants said they would continue receiving services and 94.4% would recommend peer navigation to a friend. A priori feasibility criteria were met: 92% of eligible participants enrolled and 70% were retained at 9 months; however, only 47% achieved moderate or better adherence to both in-person and phone/text program components. Though the pilot was not powered for efficacy, ITT findings trended toward significance, with intervention participants 40% more likely to be retained in care at the end of the study. Population-specific peer programming to support care engagement is acceptable, feasible, and can improve HIV outcomes for Trans women living with HIV.

RESUMEN: Las mujeres transgénero que viven con VIH (MTV) tienen una participación subóptima en la atención del VIH. Nosotros evaluamos el programa piloto "Trans Amigas", una intervención de navegación (o acompañamiento) de pares (NP) basada en un marco teórico, diseñado específicamente para mujeres transgénero, para abordar las dificultades de acceso a la salud en São Paulo, Brasil. MTV fueron asignadas de manera aleatoria a la intervención (n = 75) o a la condición de control (n = 38). Las participantes del grupo control fueron referidas a una unidad con servicios especializados para MTV. Las participantes en la intervención fueron asignadas a una navegadora, quien realizó nueve sesiones individuales en persona, así como llamadas telefónicas o mensajes de texto cada dos semanas para ayudar a las participantes a superar las barreras de acceso a la atención médica y avanzar hacia sus metas de afirmación de género y de salud. Seguimos a las participantes durante nueve meses para determinar factibilidad, aceptabilidad y eficacia preliminar en la retención en los servicios médicos. Usamos análisis por intención de tratar (AIT). La aceptabilidad de la intervención fue alta: 85.2% de las participantes NP dijeron que les gustaría seguir recibiendo los servicios NP, y 94.4% recomendarían NP a una amiga. El criterio de factibilidad a priori fue alcanzado: 92% de las participantes eligibles se inscribió y el 70% continuó por nueve meses. Sin embargo, solo el 47% alcanzó una adherencia moderada o alta tanto a las visitas en persona como a los mensajes de texto/llamadas telefónicas. Aunque el estudio piloto no tuvo el poder necesario para evaluar eficacia, el AIT reveló una tendencia hacia la significancia de que las participantes de la intervención tuvieran uma retención en la atención médica un 40% mayor. Los programas NP que apoyan el la participación en la atención del VIH, diseñados especificamente para la población, son aceptables, factibles, y pueden mejorar la situación de salud de las mujeres transgénero que viven con VIH.

Predicting incident dementia and mild cognitive impairment in older women with nonparametric analysis of circadian activity rhythms in the Study of Osteoporotic Fractures.

STUDY OBJECTIVES: Disrupted daily rhythms are associated with mild cognitive impairment (MCI) and dementia. The specific nature of how rhythms and cognition are related, however, is unknown. We hypothesized characteristics from a nonparametric estimate of circadian rest-activity rhythm patterns would be associated to the development of MCI or dementia. METHODS: Wrist actigraphy from 1232 cognitively healthy, community-dwelling women (mean age 82.6 years) from the Study of Osteoporotic Fractures was used to estimate rest-activity patterns, including intradaily variability (IV), interdaily stability (IS), most active 10-hour period (M10), least active 5-hour period (L5), and relative amplitude (RA). Logistic regression examined associations of these predictors with 5-year incidence of MCI or dementia. Models were adjusted for potential confounders. RESULTS: Women with earlier sleep/wake times had higher risk of dementia, but not MCI, (early vs. average L5 midpoint: OR, 1.66; 95% CI, 1.08-2.55) as did women with smaller day/night activity differentials (low vs. high RA: OR, 1.96; 95% CI, 1.14-3.35). IV, IS, and M10 were not associated with MCI or dementia. CONCLUSION: The timing and difference in day/night amplitude, but not variability of activity, may be useful as predictors of dementia.

Distinction of Fly Artifacts from Human Blood using Immunodetection.

Insect stains produced by necrophagous flies are indistinguishable morphologically from human bloodstains. At present, no diagnostic tests exist to overcome this deficiency. As the first step toward developing a chemical test to recognize fly artifacts, polyclonal antisera were generated in rats against three distinct antigenic sequences of fly cathepsin D-like proteinase, an enzyme that is structurally distinct in cyclorrhaphous Diptera from other animals. The resulting rat antisera bound to artifacts produced by Protophormia terraenovae and synthetic peptides used to generate the polyclonal antisera, but not with any type of mammalian blood tested in immunoassays. Among the three antisera, anti-md3 serum displayed the highest reactivity for fly stains, demonstrated cross-reactivity for all synthetic peptides representing antigenic sequences of the mature fly enzyme, and bound artifacts originating from the fly digestive tract. Further work is needed to determine whether the antisera are suitable for non-laboratory conditions.

Addressing the risk of bacterial contamination in platelets: a hospital economic perspective.

BACKGROUND: Bacterially contaminated platelets (PLTs) remain a serious risk. The Food and Drug Administration has issued draft guidance recommending hospitals implement secondary testing or transfuse PLTs that have been treated with pathogen reduction technology (PRT). The cost implications of these approaches are not well understood. STUDY DESIGN AND METHODS: We modeled incurred costs when hospitals acquire, process, and transfuse PLTs that are PRT treated with INTERCEPT (Cerus Corp.) or secondary tested with the PLT PGD Test (Verax Biomedical). RESULTS: Hospitals will spend $221.27 (30.0%) more per PRT-treated apheresis PLT unit administered compared to a Zika-tested apheresis PLT unit that is irradiated and PGD tested in hospital. This difference is reflected in PRT PLT units having: 1) a higher hospital purchase price ($100.00 additional charge compared to an untreated PLT); 2) lower therapeutic effectiveness than untreated PLTs among hematologic-oncologic patients, which contributes to additional transfusions ($96.05); or 3) fewer PLT storage days, which contributes to higher outdating cost from expired PLTs ($67.87). Only a small portion of the incremental costs for PRT-treated PLTs are offset by costs that may be avoided, including primary bacterial culture, secondary bacterial testing ($26.65), hospital irradiation ($8.50), Zika testing ($4.47), and other costs ($3.03). CONCLUSION: The significantly higher cost of PRT-treated PLTs over PGD-tested PLTs should interest stakeholders. For hospitals that outdate PLTs, savings associated with expiration extension to 7 days by adding PGD testing will likely be substantially greater than the cost of implementing PGD-testing. Our findings might usefully inform a hospital's decision to select a particular blood safety approach.

Substrate stiffness regulates primary hepatocyte functions.

Liver fibrosis occurs as a consequence of chronic injuries from viral infections, metabolic disorders, and alcohol abuse. Fibrotic liver microenvironment (LME) is characterized by excessive deposition and aberrant turnover of extracellular matrix proteins, which leads to increased tissue stiffness. Liver stiffness acts as a vital cue in the regulation of hepatic responses in both healthy and diseased states; however, the effect of varying stiffness on liver cells is not well understood. There is a critical need to engineer in vitro models that mimic the liver stiffness corresponding to various stages of disease progression in order to elucidate the role of individual cellular responses. Here we employed polydimethyl siloxane (PDMS) based substrates with tunable mechanical properties to investigate the effect of substrate stiffness on the behavior of primary rat hepatocytes. To recreate physiologically relevant stiffness, we designed soft substrates (2 kPa) to represent the healthy liver and stiff substrates (55 kPa) to represent the diseased liver. Tissue culture plate surface (TCPS) served as the control substrate. We observed that hepatocytes cultured on soft substrates displayed a more differentiated and functional phenotype for a longer duration as compared to stiff substrates and TCPS. We demonstrated that hepatocytes on soft substrates exhibited higher urea and albumin synthesis. Cytochrome P450 (CYP) activity, another critical marker of hepatocytes, displayed a strong dependence on substrate stiffness, wherein hepatocytes on soft substrates retained 2.7 fold higher CYP activity on day 7 in culture, as compared to TCPS. We further observed that an increase in stiffness induced downregulation of key drug transporter genes (NTCP, UGT1A1, and GSTM-2). In addition, we observed that the epithelial cell phenotype was better maintained on soft substrates as indicated by higher expression of hepatocyte nuclear factor 4α, cytokeratin 18, and connexin 32. These results indicate that the substrate stiffness plays a significant role in modulating hepatocyte behavior. Our PDMS based liver model can be utilized to investigate the signaling pathways mediating the hepatocyte-LME communication to understand the progression of liver diseases.