Bilayer-spanning DNA nanopores with voltage-switching between open and closed state.

Membrane-spanning nanopores from folded DNA are a recent example of biomimetic man-made nanostructures that can open up applications in biosensing, drug delivery, and nanofluidics. In this report, we generate a DNA nanopore based on the archetypal six-helix-bundle architecture and systematically characterize it via single-channel current recordings to address several fundamental scientific questions in this emerging field. We establish that the DNA pores exhibit two voltage-dependent conductance states. Low transmembrane voltages favor a stable high-conductance level, which corresponds to an unobstructed DNA pore. The expected inner width of the open channel is confirmed by measuring the conductance change as a function of poly(ethylene glycol) (PEG) size, whereby smaller PEGs are assumed to enter the pore. PEG sizing also clarifies that the main ion-conducting path runs through the membrane-spanning channel lumen as opposed to any proposed gap between the outer pore wall and the lipid bilayer. At higher voltages, the channel shows a main low-conductance state probably caused by electric-field-induced changes of the DNA pore in its conformation or orientation. This voltage-dependent switching between the open and closed states is observed with planar lipid bilayers as well as bilayers mounted on glass nanopipettes. These findings settle a discrepancy between two previously published conductances. By systematically exploring a large space of parameters and answering key questions, our report supports the development of DNA nanopores for nanobiotechnology.The SH lab is supported by the Leverhulme Trust (RPG-170), UCL Chemistry, EPSRC (Institutional Sponsorship Award), the National Physical Laboratory, and Oxford Nanopore Technologies. KG acknowledges funding from the Winton Program of Physics for Sustainability, Gates Cambridge and the Oppenheimer Trust. UFK was supported by an ERC starting grant #261101.This is the final version of the article. It was first published by ACS under the ACS AuthorChoice license at http://dx.doi.org/10.1021/nn5039433 This permits copying and redistribution of the article or any adaptations for non-commercial purposes

A DNA turbine powered by a transmembrane potential across a nanopore

Rotary motors play key roles in energy transduction, from macroscale windmills to nanoscale turbines such as ATP synthase in cells. Despite our abilities to construct engines at many scales, developing functional synthetic turbines at the nanoscale has remained challenging. Here, we experimentally demonstrate rationally designed nanoscale DNA origami turbines with three chiral blades. These DNA nanoturbines are 24–27 nm in height and diameter and can utilize transmembrane electrochemical potentials across nanopores to drive DNA bundles into sustained unidirectional rotations of up to 10 revolutions s−1. The rotation direction is set by the designed chirality of the turbine. All-atom molecular dynamics simulations show how hydrodynamic flows drive this turbine. At high salt concentrations, the rotation direction of turbines with the same chirality is reversed, which is explained by a change in the anisotropy of the electrophoretic mobility. Our artificial turbines operate autonomously in physiological conditions, converting energy from naturally abundant electrochemical potentials into mechanical work. The results open new possibilities for engineering active robotics at the nanoscale

National multi-stakeholder meetings: a tool to support development of integrated policies and practices for testing and prevention of HIV, viral hepatitis, TB and STIs

Background Country level policies and practices of testing and care for HIV, viral hepatitis and sexually transmitted infections are lagging behind European recommendations on integration across diseases. Building on previous experiences and evidence, the INTEGRATE Joint Action arranged four national stakeholder meetings. The aim was to foster cross-disciplinary and cross-disease collaborations at national level as a vehicle for strengthened integration of testing and care services. This article presents the methodology and discusses main outcomes and recommendations of these meetings. Methods Local partners in Croatia, Italy, Lithuania and Poland oversaw the planning, agenda development and identification of key persons to invite to ensure that meetings addressed main challenges and issues of the respective countries. Invited national stakeholders represented policy and public health institutions, clinical settings, testing sites and community organisations. National experts and experts from other European countries were invited as speakers and facilitators. Main topic discussed was how to increase integration across HIV, viral hepatitis and sexually transmitted infections in testing and care policies and practice; tuberculosis was also addressed in Lithuania and Italy. Results The agendas reflected national contexts and the meetings provided a forum to engage stakeholders knowledgeable of the national prevention, testing and care systems in interaction with international experts who shared experiences of the steps needed to achieve integration in policies and practice. The evaluations showed that participants found meetings relevant, important and beneficial for furthering integration. Of the respondents 78% agreed or strongly agreed that there was a good representation of relevant national stakeholders, and 78% that decision/action points were made on how to move the agenda forward. The importance of securing participation from high level national policy makers was highlighted. Outcomes were nationally tailored recommendations on integrated policies and strategies, diversification of testing strategies, stigma and discrimination, key populations, cost effectiveness, surveillance and funding. Conclusions Shifting from single to multi-disease approaches require collaboration among a broad range of actors and national multi-stakeholder meetings have proven excellent to kick-start this. Face-to-face meetings of key stakeholders represent a unique opportunity to share cross-sectoral perspectives and experiences, identify gaps in national policies and practices and agree on required next steps.The INTEGRATE Joint Action was co-funded by the 3rd Health Programme of the European Union under grant agreement no 761319. National meetings and trainings were co-funded by EuroTEST’s grants from Merck and Janssen. Daniel Simões is the recipient of PhD Grant PD/BD/128008/2016 from Fundação para a Ciência e Tecnologia (FCT). All funders had no role in the study design, analysis, decision to publish, or preparation of the manuscript

Safety, Tolerability, and Preliminary Efficacy of TAR-200 in Patients with Muscle-invasive Bladder Cancer Who Refused or Were Unfit for Curative-intent Therapy : A Phase 1 Study

Half of patients with muscle-invasive bladder cancer worldwide may not receive curative-intent therapy. Elderly or frail patients are most affected by this unmet need. TAR-200 is a novel, intravesical drug delivery system that provides sustained, local release of gemcitabine into the bladder over a 21-day dosing cycle. The phase 1 TAR-200-103 study evaluated the safety, tolerability, and preliminary efficacy of TAR-200 in patients with muscle-invasive bladder cancer who either refused or were unfit for curative-intent therapy.Materials and Eligible patients had cT2-cT3bN0M0 urothelial carcinoma of the bladder. TAR-200 was inserted for 4 consecutive 21-day cycles over 84 days. The primary end points were safety and tolerability at 84 days. Secondary end points included rates of clinical complete response and partial response as determined by cystoscopy, biopsy, and imaging; duration of response; and overall survival. Median age of the 35 enrolled patients was 84 years, and most were male (24/35, 68.6%). Treatment-emergent adverse events related to TAR-200 occurred in 15 patients. Two patients experienced treatment-emergent adverse events leading to removal of TAR-200. At 3 months, complete response and partial response rates were 31.4% (11/35) and 8.6% (3/35), respectively, yielding an overall response rate of 40.0% (14/35; 95% CI 23.9-57.9). Median overall survival and duration of response were 27.3 months (95% CI 10.1-not estimable) and 14 months (95% CI 10.6-22.7), respectively. Progression-free rate at 12 months was 70.5%. TAR-200 was generally safe, well tolerated, and had beneficial preliminary efficacy in this elderly and frail cohort with limited treatment options

Patent foramen ovale occlusion with the Cocoon PFO Occluder. The PROS-IT collaborative project

Background: the Cocoon patent foramen ovale (PFO) Occluder is a new generation nitinol alloy double-disk device coated with nanoplatinum, likely useful in patients with nickel hypersensitivity. Early results and mid-term outcomes of this device in percutaneous PFO closure are missing. Aims: to assess the preliminary ecacy and safety profile of PFO closure with Cocoon device in an Italian multi-center registry. Methods: This is a prospective registry of 189 consecutive adult patients treated with the Cocoon PFO Occluder at 15 Italian centers from May 2017 till May 2020. Patients were followed up for 2 years. Results: closure of the PFO with Cocoon Occluder was carried out successfully in all patients, with complete closure without residual shunt in 94.7% of the patients and minimal shunt in 5.3%. Except from a case of paroxysmal supraventricular tachycardia and a major vascular bleeding, no procedural and in-hospital device-related complications occurred. No patient developed cardiac erosions, allergic reactions to nickel, or any other major complications during the follow-up. During the follow-up period, 2 cases of new-onset atrial fibrillation occurred within thirty-

Environmental toxins and breast cancer on Long Island. I. Polycyclic aromatic hydrocarbon DNA adducts

Polycyclic aromatic hydrocarbons (PAH) are potent mammary carcinogens in rodents, but their effect on breast cancer development in women is not clear. To examine whether currently measurable PAH damage to DNA increases breast cancer risk, a population-based case-control study was undertaken on Long Island, NY. Cases were women newly diagnosed with in situ and invasive breast cancer; controls were randomly selected women frequency matched to the age distribution of cases. Blood samples were donated by 1102 (73.0%) and 1141 (73.3%) of case and control respondents, respectively. Samples from 576 cases and 427 controls were assayed for PAH-DNA adducts using an ELISA. The geometric mean (and geometric SD) of the log-transformed levels of PAH-DNA adducts on a natural scale was slightly, but nonsignificantly, higher among cases [7.36 (7.29)] than among controls [6.21 (4.17); p = 0.51]. The age-adjusted odds ratio (OR) for breast cancer in relation to the highest quintile of adduct levels compared with the lowest was 1.51 [95% confidence interval (CI), 1.04 –2.20], with little or no evidence of substantial confounding (corresponding multivariate-adjusted OR, 1.49; 95% CI, 1.00 –2.21). There was no consistent elevation in risk with increasing adduct levels, nor was there a consistent association between adduct levels and two of the main sources of PAH, active or passive cigarette smoking or consumption of grilled and smoked foods. These data indicate that PAH-DNA adduct formation may influence breast cancer development, although the association does not appear to be dose dependent and may have a threshold effect

Environmental toxins and breast cancer on Long Island. II. Organochlorine compound levels in blood

Whether environmental contaminants increase breast cancer risk among women on Long Island, NY, is unknown. The study objective is to determine whether breast cancer risk is increased in relation to organochlorines, compounds with known estrogenic characteristics that were extensively used on Long Island and other areas of the United States. Recent reports do not support a strong association, although there are concerns with high risks observed in subgroups of women. Blood samples from 646 case and 429 control women from a population-based case-control study conducted on Long Island were analyzed. No substantial elevation in breast cancer risk was observed in relation to the highest quintile of lipid-adjusted serum levels of p,p'-bis(4-chlorophenyl)-1,1-dichloroethene (DDE) [odds ratio (OR), 1.20 versus lowest quintile; 95% confidence interval (CI), 0.76 –1.90], chlordane (OR, 0.98; 95% CI, 0.62–1.55), dieldrin (OR, 1.37; 95% CI, 0.69 –2.72), the sum of the four most frequently occurring PCB congeners (nos. 118, 153, 138, and 180; OR, 0.83; 95% CI, 0.54 –1.29), and other PCB congener groupings. No dose-response relations were apparent. Nor was risk increased in relation to organochlorines among women who had not breastfed or were overweight, postmenopausal, or long-term residents of Long Island; or with whether the case was diagnosed with invasive rather than in situ disease, or with a hormone receptor-positive tumor. These findings, based on the largest number of samples analyzed to date among primarily white women, do not support the hypothesis that organochlorines increase breast cancer risk among Long Island women

The Long Island Breast Cancer Study Project: description of a multi-institutional collaboration to identify environmental risk factors for breast cancer

The Long Island Breast Cancer Study Project is a federally mandated, population-based case-control study to determine whether breast cancer risk among women in the counties of Nassau and Suffolk, NY, is associated with selected environmental exposures, assessed by blood samples, self-reports, and environmental home samples. This report describes the collaborative project’s background, rationale, methods, participation rates, and distributions of known risk factors for breast cancer by case-control status, by blood donation, and by availability of environmental home samples. Interview response rates among eligible cases and controls were 82.1% (n=1,508) and 62.8% (n=1,556), respectively. Among case and control respondents who completed the interviewer-administered questionnaire, 98.2 and 97.6% self-completed the food frequency questionnaire; 73.0 and 73.3% donated a blood sample; and 93.0 and 83.3% donated a urine sample. Among a random sample of case and control respondents who are long-term residents, samples of dust (83.6 and 83.0%); soil (93.5 and 89.7%); and water (94.3 and 93.9%) were collected. Established risk factors for breast cancer that were found to increase risk among Long Island women include lower parity, late age at first birth, little or no breast feeding, and family history of breast cancer. Factors that were found to be associated with a decreased likelihood that a respondent would donate blood include increasing age and past smoking; factors associated with an increased probability include white or other race, alcohol use, ever breastfed, ever use of hormone replacement therapy, ever use of oral contraceptives, and ever had a mammogram. Long-term residents (defined as 15+ years in the interview home) with environmental home samples did not differ from other long-term residents, although there were a number of differences in risk factor distributions between long-term residents and other participants, as anticipated