Molecular electronics sensors on a scalable semiconductor chip: A platform for single-molecule measurement of binding kinetics and enzyme activity.

For nearly 50 years, the vision of using single molecules in circuits has been seen as providing the ultimate miniaturization of electronic chips. An advanced example of such a molecular electronics chip is presented here, with the important distinction that the molecular circuit elements play the role of general-purpose single-molecule sensors. The device consists of a semiconductor chip with a scalable array architecture. Each array element contains a synthetic molecular wire assembled to span nanoelectrodes in a current monitoring circuit. A central conjugation site is used to attach a single probe molecule that defines the target of the sensor. The chip digitizes the resulting picoamp-scale current-versus-time readout from each sensor element of the array at a rate of 1,000 frames per second. This provides detailed electrical signatures of the single-molecule interactions between the probe and targets present in a solution-phase test sample. This platform is used to measure the interaction kinetics of single molecules, without the use of labels, in a massively parallel fashion. To demonstrate broad applicability, examples are shown for probe molecule binding, including DNA oligos, aptamers, antibodies, and antigens, and the activity of enzymes relevant to diagnostics and sequencing, including a CRISPR/Cas enzyme binding a target DNA, and a DNA polymerase enzyme incorporating nucleotides as it copies a DNA template. All of these applications are accomplished with high sensitivity and resolution, on a manufacturable, scalable, all-electronic semiconductor chip device, thereby bringing the power of modern chips to these diverse areas of biosensing.

Understanding constraints on integrated care for people with HIV and multimorbid cardiovascular conditions: an application of the Theoretical Domains Framework.

BACKGROUND: People with HIV (PWH) experience increased cardiovascular disease (CVD) risk. Many PWH in the USA receive their primary medical care from infectious disease specialists in HIV clinics. HIV care teams may not be fully prepared to provide evidence-based CVD care. We sought to describe local context for HIV clinics participating in an NIH-funded implementation trial and to identify facilitators and barriers to integrated CVD preventive care for PWH. METHODS: Data were collected in semi-structured interviews and focus groups with PWH and multidisciplinary healthcare providers at three academic medical centers. We used template analysis to identify barriers and facilitators of CVD preventive care in three HIV specialty clinics using the Theoretical Domains Framework (TDF). RESULTS: Six focus groups were conducted with 37 PWH. Individual interviews were conducted with 34 healthcare providers and 14 PWH. Major themes were captured in seven TDF domains. Within those themes, we identified nine facilitators and 11 barriers to CVD preventive care. Knowledge gaps contributed to inaccurate CVD risk perceptions and ineffective self-management practices in PWH. Exclusive prioritization of HIV over CVD-related conditions was common in PWH and their providers. HIV care providers assumed inconsistent roles in CVD prevention, including for PWH with primary care providers. HIV providers were knowledgeable of HIV-related CVD risks and co-located health resources were consistently available to support PWH with limited resources in health behavior change. However, infrequent medical visits, perceptions of CVD prevention as a primary care service, and multiple co-location of support programs introduced local challenges to engaging in CVD preventive care. CONCLUSIONS: Barriers to screening and treatment of cardiovascular conditions are common in HIV care settings and highlight a need for greater primary care integration. Improving long-term cardiovascular outcomes of PWH will likely require multi-level interventions supporting HIV providers to expand their scope of practice, addressing patient preferences for co-located CVD preventive care, changing clinic cultures that focus only on HIV to the exclusion of non-AIDS multimorbidity, and managing constraints associated with multiple services co-location. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03643705.

Loss of 15-hydroxyprostaglandin dehydrogenase expression disrupts urothelial differentiation.

OBJECTIVES: Urothelial differentiation is essential for the maintenance of urinary bladder function. We explored the expression and function of 15-hydroxyprostaglandin dehydrogenase (PGDH) during urothelial differentiation. METHODS: We evaluated expression of PGDH by Northern and Western blotting and immunostaining in human urothelial cultures, cell lines, and tissues. We determined enzymatic function using enzyme-linked immunosorbent assay. Small inhibitory ribonucleic acids were used to inhibit PGDH expression in human bladder cancer cells. RESULTS: We found PGDH messenger ribonucleic acid was increased in an in vitro model of human urothelial differentiation by Northern blotting. Western blotting of human bladder cancer cell lines showed expression in the well-differentiated RT4 cells and no expression in poorly differentiated UC3 cells. Immunostaining showed that PGDH expression increased with differentiation in normal bladder urothelium. The enzyme was functional in the well-differentiated RT4 human bladder cancer cell line. Inhibition of PGDH expression resulted in disruption of E-cadherin expression at cell-cell contacts in well-differentiated RT4 bladder cancer cells. CONCLUSIONS: These studies indicate that PGDH expression is associated with urothelial differentiation, and loss of PGDH expression results in disruption of urothelial differentiation.