Correction: Re-pairing DNA: binding of a ruthenium phi complex to a double mismatch.

[This corrects the article DOI: 10.1039/D4SC01448K.].

Kappa opioids inhibit spinal output neurons to suppress itch.

Itch is a protective sensation that drives scratching. Although specific cell types have been proposed to underlie itch, the neural basis for itch remains unclear. Here, we used two-photon Ca2+ imaging of the dorsal horn to visualize neuronal populations that are activated by itch-inducing agents. We identify a convergent population of spinal interneurons recruited by diverse itch-causing stimuli that represents a subset of neurons that express the gastrin-releasing peptide receptor (GRPR). Moreover, we find that itch is conveyed to the brain via GRPR-expressing spinal output neurons that target the lateral parabrachial nuclei. We then show that the kappa opioid receptor agonist nalfurafine relieves itch by selectively inhibiting GRPR spinoparabrachial neurons. These experiments provide a population-level view of the spinal neurons that respond to pruritic stimuli, pinpoint the output neurons that convey itch to the brain, and identify the cellular target of kappa opioid receptor agonists for the inhibition of itch.

Re-pairing DNA: binding of a ruthenium phi complex to a double mismatch.

We report a crystal structure at atomic resolution (0.9 Å) of a ruthenium complex bound to a consecutive DNA double mismatch, which results in a TA basepair with flipped out thymine, together with the formation of an adenine bulge. The structure shows a form of metalloinsertion interaction of the Λ-[Ru(phen)2phi]2+ (phi = 9,10-phenanthrenediimine) complex at the bulge site. The metal complex interacts with the DNA via the major groove, where specific interactions between the adenines of the DNA and the phen ligands of the complex are formed. One Δ-[Ru(phen)2phi]2+ complex interacts via the minor groove, which shows sandwiching of its phi ligand between the phi ligands of the other two ruthenium complexes, and no interaction of its phen ligands with DNA. To our knowledge, this binding model represents a new form of metalloinsertion in showing major rather than minor groove insertion.

Outcomes following spinal instrumented fusions in patients with parkinson's disease: a systematic review and meta-analysis.

BACKGROUND: Parkinson's Disease (PD) patients represent challenging spinal surgery candidates due to associated frailty and deformity. This study consolidates the literature concerning spinal surgery outcomes in PD versus non-PD patients, to evaluate if PD predisposes patients to worse post-operative outcomes, so that treatment protocols can be optimised. METHODS: A systematic review and meta-analysis was conducted of PubMed/Medline, Embase, and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies of interest included comparative (PD versus non-PD) cohorts undergoing spinal instrumented fusions. Post-operative clinical outcomes were collated and compared for significance between cohorts. Further analysis was made on outcomes based on the different surgical procedures performed (Anterior Cervical Discectomy and Fusion (ACDF), Thoracolumbar or Lumbar fusions, Thoracolumbar or Lumbar fusions without Osteoporotic Vertebral Compression fracture (OVCF) patients). All statistical analysis was performed using The R Project for Statistical Computing (version 4.1.2), with a p-value of < 0.05 deemed statistically significant. RESULTS: In total, 2,323,650 patients were included across 16 studies. Of those, 2,308,949 (99.37%) were patients without PD (non-PD), while 14,701 (0.63%) patients had PD at time of surgery. The collective mean age was 68.23 years (PD: 70.14 years vs non-PD: 64.86 years). Comparatively, there were 844,641 males (PD: 4,574; non-PD: 840,067) and 959,908 females (PD: 3,213; non-PD: 956,695). Overall, there were more post-operative complications in the PD cohort. Specifically, PD patients experienced significantly more surgical site infections (p = 0.01), increased rates of revision surgeries (p = 0.04) and increased venous thromboembolic events (p = 0.02) versus the non-PD cohort. In thoracolumbar/lumbar spinal fusions without OVCF patients, the PD cohort had increased rates of revision surgeries (p < 0.01) in comparison to the non-PD cohort. However, when including OVCF patients in thoracolumbar/lumbar spinal fusions, the PD cohort had significantly higher amounts of postoperative complications (p = 0.01), pneumonia (p = 0.02), and revision surgeries (p < 0.01) when compared to the non-PD cohort. CONCLUSION: Although more robust prospective studies are needed, the results of this study highlight the need for advanced wound care management in the postoperative period, both in-hospital and in the community, in addition to comprehensive multidisciplinary care from allied health professionals, with potential for the use of Enhanced Recovery After Surgery (ERAS) protocols in PD patients undergoing spinal instrumented fusions.

Emergency Department Use Among Adults Receiving Dialysis.

Importance: People with kidney failure receiving maintenance dialysis visit the emergency department (ED) 3 times per year on average, which is 3- to 8-fold more often than the general population. Little is known about the factors that contribute to potentially preventable ED use in this population. Objective: To identify the clinical and sociodemographic factors associated with potentially preventable ED use among patients receiving maintenance dialysis. Design, Setting, and Participants: This cohort study used linked administrative health data within the Alberta Kidney Disease Network to identify adults aged 18 years or older receiving maintenance dialysis (ie, hemodialysis or peritoneal dialysis) between April 1, 2010, and March 31, 2019. Patients who had been receiving dialysis for more than 90 days were followed up from cohort entry (defined as dialysis start date plus 90 days) until death, outmigration from the province, receipt of a kidney transplant, or end of study follow-up. The Andersen behavioral model of health services was used as a conceptual framework to identify variables related to health care need, predisposing factors, and enabling factors. Data were analyzed in March 2024. Main Outcomes and Measures: Rates of all-cause ED encounters and potentially preventable ED use associated with 4 kidney disease-specific ambulatory care-sensitive conditions (hyperkalemia, heart failure, volume overload, and malignant hypertension) were calculated. Multivariable negative binomial regression models were used to examine the association between clinical and sociodemographic factors and rates of potentially preventable ED use. Results: The cohort included 4925 adults (mean [SD] age, 60.8 [15.5] years; 3071 males [62.4%]) with kidney failure receiving maintenance hemodialysis (3183 patients) or peritoneal dialysis (1742 patients) who were followed up for a mean (SD) of 2.5 (2.0) years. In all, 3877 patients had 34 029 all-cause ED encounters (3100 [95% CI, 2996-3206] encounters per 1000 person-years). Of these, 755 patients (19.5%) had 1351 potentially preventable ED encounters (114 [95% CI, 105-124] encounters per 1000 person-years). Compared with patients with a nonpreventable ED encounter, patients with a potentially preventable ED encounter were more likely to be in the lowest income quintile (38.8% vs 30.9%; P < .001); to experience heart failure (46.8% vs 39.9%; P = .001), depression (36.6% vs 32.5%; P = .03), and chronic pain (60.1% vs 54.9%; P = .01); and to have a longer duration of dialysis (3.6 vs 2.6 years; P < .001). In multivariable regression analyses, potentially preventable ED use was higher for younger adults (incidence rate ratio [IRR], 1.69 [95% CI, 1.33-2.15] for those aged 18 to 44 years) and patients with chronic pain (IRR, 1.35 [95% CI, 1.14-1.61]), greater material deprivation (IRR, 1.57 [95% CI, 1.16-2.12]), a history of hyperkalemia (IRR, 1.31 [95% CI, 1.09-1.58]), and historically high ED use (ie, ≥3 ED encounters in the prior year; IRR, 1.46 [95% CI, 1.23-1.73). Conclusions and Relevance: In this study of adults receiving maintenance dialysis in Alberta, Canada, among those with ED use, 1 in 5 had a potentially preventable ED encounter; reasons for such encounters were associated with both psychosocial and medical factors. The findings underscore the need for strategies that address social determinants of health to avert potentially preventable ED use in this population.

The efficacy of anchored stand-alone spacers in comparison to conventional cage and plate in anterior cervical discectomy and fusion surgery: A meta-analysis of randomised controlled trials for clinical and radiological outcomes.

Introduction: Anterior cervical discectomy and fusion (ACDF) is commonly performed with cage and plate constructs to stabilise diseased or injured cervical segments. Despite it being a commonly performed procedure, there are notable rates of associated morbidity reported in the literature. Stand-alone spacers represent a novel form of instrumentation to conventional cage and plate constructs. Research question: Do stand-alone spacers have improved operative characteristics and postoperative outcomes in ACDF cohorts when compared to cage and plate constructs? Methods: A systematic review and meta-analysis was conducted of PubMed/Medline, Embase and Google Scholar databases per the Preferred Reporting Items for Systematic Reviews and Meta-Analyzes guidelines. Studies of interest included cage and plate instrumentation versus anchored stand-alone spacers for patients undergoing ACDF. Pre- and post-operative clinical and radiological outcomes were collated and compared for significance between cohorts. Results: 10 RCTs were identified and included with 779 patients total. Mean age of the entire cohort was 50.1 years. 62% (483/779) of the cohort were male. 384 patients underwent ACDF with stand-alone cage, while 395 had ACDF with conventional cage and plate. Stand-alone spacers significantly outperformed conventional instrumentation in terms of estimated blood loss (p < 0.01), total postoperative complications (p < 0.01), dysphagia rates (p = 0.04) and adjacent segment disease (p = 0.04). Non-inferiority was evident in both patient reported outcome measures and radiological outcomes. Conclusion: This meta-analysis highlights the efficacy of stand-alone spacers for the management of primarily cervical spondylitic disease for both single-level and multi-level pathology, and thus presents an attractive alternative to conventional instrumentation for patients undergoing ACDF surgery.

Probing a Major DNA Weakness: Resolving the Groove and Sequence Selectivity of the Diimine Complex Λ-[Ru(phen)2 phi]2.

The grooves of DNA provide recognition sites for many nucleic acid binding proteins and anticancer drugs such as the covalently binding cisplatin. Here we report a crystal structure showing, for the first time, groove selectivity by an intercalating ruthenium complex. The complex Λ-[Ru(phen)2 phi]2+ , where phi=9,10-phenanthrenediimine, is bound to the DNA decamer duplex d(CCGGTACCGG)2 . The structure shows that the metal complex is symmetrically bound in the major groove at the central TA/TA step, and asymmetrically bound in the minor groove at the adjacent GG/CC steps. A third type of binding links the strands, in which each terminal cytosine base stacks with one phen ligand. The overall binding stoichiometry is four Ru complexes per duplex. Complementary biophysical measurements confirm the binding preference for the Λ-enantiomer and show a high affinity for TA/TA steps and, more generally, TA-rich sequences. A striking enantiospecific elevation of melting temperatures is found for oligonucleotides which include the TATA box sequence.

Lessons learned from the Alberta Border Testing Pilot Program.

Background: During the Coronavirus disease (COVID-19) pandemic, countries implemented border control and quarantine measures to reduce transmission. The Alberta Border Testing Pilot Program (ABTPP) allowed international travellers entering Alberta to reduce their quarantine period following two negative COVID-19 tests. We evaluated participant experiences with the ABTPP and implementation. Method: We used a parallel convergent mixed-methods design to explore participant experiences through electronic web-based questionnaires (n = 21,089; n = 13,839) and semi-structured telephone interviews (n = 30). We evaluated implementation through three staff focus groups (n = 11). We analysed questionnaires using descriptive statistics and analysed interviews using inductive and deductive thematic analysis. We deductively coded focus group data using the 2009 Consolidated Framework for Implementation Research (CFIR). Results: Questionnaires indicated minimal issues with registration forms (91.7%), symptom reports (95.5%), and COVID-19 testing (95.7%). Most respondents (95.1%) expressed willingness to participate in the ABTPP again. Interviews revealed three themes related to participant experience: program efficiency, clarity of information, and requisite effort. Focus groups identified key implementation facilitators including the single health information system, strong stakeholder partnerships, and good communication across partnerships. Barriers included program complexity, implementation timeline, and evolving external context. Discussion: Participants reported high satisfaction with the ABTPP. Border testing programs should have high efficiency, require low effort, and use messaging that is clear and consistent. The effective implementation of border testing programs may be facilitated by strong leadership, adaptability, automated components, good communication, and simple technology. Learnings from participants and staff may help improve the implementation of border control programs for future pandemics or other emergencies. Conclusions: The ABTTP was a novel border control measure during the COVID-19 pandemic. Our evaluation of both participant and staff experiences demonstrated high levels of traveller satisfaction and identified areas for improvement that can inform the development of future border control measures.

The Drosophila drop-dead gene is required for eggshell integrity.

The eggshell of the fruit fly Drosophila melanogaster is a useful model for understanding the synthesis of a complex extracellular matrix. The eggshell is synthesized during mid-to-late oogenesis by the somatic follicle cells that surround the developing oocyte. We previously reported that female flies mutant for the gene drop-dead (drd) are sterile, but the underlying cause of the sterility remained unknown. In this study, we examined the role of drd in eggshell synthesis. We show that eggs laid by drd mutant females are fertilized but arrest early in embryogenesis, and that the innermost layer of the eggshell, the vitelline membrane, is abnormally permeable to dye in these eggs. In addition, the major vitelline membrane proteins fail to become crosslinked by nonreducible bonds, a process that normally occurs during egg activation following ovulation, as evidenced by their solubility and detection by Western blot in laid eggs. In contrast, the Cp36 protein, which is found in the outer chorion layers of the eggshell, becomes crosslinked normally. To link the drd expression pattern with these phenotypes, we show that drd is expressed in the ovarian follicle cells beginning in mid-oogenesis, and, importantly, that all drd mutant eggshell phenotypes could be recapitulated by selective knockdown of drd expression in the follicle cells. To determine whether drd expression was required for the crosslinking itself, we performed in vitro activation and crosslinking experiments. The vitelline membranes of control egg chambers could become crosslinked either by incubation in hyperosmotic medium, which activates the egg chambers, or by exogenous peroxidase and hydrogen peroxide. In contrast, neither treatment resulted in the crosslinking of the vitelline membrane in drd mutant egg chambers. These results indicate that drd expression in the follicle cells is necessary for vitelline membrane proteins to serve as substrates for peroxidase-mediated cross-linking at the end of oogenesis.

Nurse Practitioner Care Compared with Primary Care or Nephrologist Care in Early CKD.

BACKGROUND: Early interventions in CKD have been shown to improve health outcomes; however, gaps in access to nephrology care remain common. Nurse practitioners can improve access to care; however, the quality and outcomes of nurse practitioner care for CKD are uncertain. METHODS: In this propensity score-matched cohort study, patients with CKD meeting criteria for nurse practitioner care were matched 1:1 on their propensity scores for ( 1 ) nurse practitioner care versus primary care alone and ( 2 ) nurse practitioner versus nephrologist care. Processes of care were measured within 1 year after cohort entry, and clinical outcomes were measured over 5 years of follow-up and compared between propensity score-matched groups. RESULTS: A total of 961 (99%) patients from the nurse practitioner clinic were matched on their propensity score to 961 (1%) patients receiving primary care only while 969 (100%) patients from the nurse practitioner clinic were matched to 969 (7%) patients receiving nephrologist care. After matching to patients receiving primary care alone, those receiving nurse practitioner care had greater use of angiotensin-converting enzyme inhibitors/angiotensin receptor blocker (82% versus 79%; absolute differences [ADs] 3.4% [95% confidence interval, 0.0% to 6.9%]) and statins (75% versus 66%; AD 9.7% [5.8% to 13.6%]), fewer prescriptions of nonsteroidal anti-inflammatory drugs (10% versus 17%; AD -7.2% [-10.4% to -4.2%]), greater eGFR and albuminuria monitoring, and lower rates of all-cause hospitalization (34.1 versus 43.3; rate difference -9.2 [-14.7 to -3.8] per 100 person-years) and all-cause mortality (3.3 versus 6.0; rate difference -2.7 [-3.6 to -1.7] per 100 person-years). When matched to patients receiving nephrologist care, those receiving nurse practitioner care were also more likely to be prescribed angiotensin-converting enzyme inhibitors/angiotensin receptor blockers and statins, with no difference in the risks of experiencing adverse clinical outcomes. CONCLUSIONS: Nurse practitioner care for patients with CKD was associated with better guideline-concordant care than primary care alone or nephrologist care, with clinical outcomes that were better than or equivalent to primary care alone and similar to those with care by nephrologists. PODCAST: This article contains a podcast at https://dts.podtrac.com/redirect.mp3/www.asn-online.org/media/podcast/CJASN/2023_12_08_CJN0000000000000305.mp3.

Increasing the π-Expansive Ligands in Ruthenium(II) Polypyridyl Complexes: Synthesis, Characterization, and Biological Evaluation for Photodynamic Therapy Applications.

Lack of selectivity is one of the main issues with currently used chemotherapies, causing damage not only to altered cells but also to healthy cells. Over the last decades, photodynamic therapy (PDT) has increased as a promising therapeutic tool due to its potential to treat diseases like cancer or bacterial infections with a high spatiotemporal control. Ruthenium(II) polypyridyl compounds are gaining attention for their application as photosensitizers (PSs) since they are generally nontoxic in dark conditions, while they show remarkable toxicity after light irradiation. In this work, four Ru(II) polypyridyl compounds with sterically expansive ligands were studied as PDT agents. The Ru(II) complexes were synthesized using an alternative route to those described in the literature, which resulted in an improvement of the synthesis yields. Solid-state structures of compounds [Ru(DIP)2phen]Cl2 and [Ru(dppz)2phen](PF6)2 have also been obtained. It is well-known that compound [Ru(dppz)(phen)2]Cl2 binds to DNA by intercalation. Therefore, we used [Ru(dppz)2phen]Cl2 as a model for DNA interaction studies, showing that it stabilized two different sequences of duplex DNA. Most of the synthesized Ru(II) derivatives showed very promising singlet oxygen quantum yields, together with noteworthy photocytotoxic properties against two different cancer cell lines, with IC50 in the micro- or even nanomolar range (0.06-7 µM). Confocal microscopy studies showed that [Ru(DIP)2phen]Cl2 and [Ru(DIP)2TAP]Cl2 accumulate preferentially in mitochondria, while no mitochondrial internalization was observed for the other compounds. Although [Ru(dppn)2phen](PF6)2 did not accumulate in mitochondria, it interestingly triggered an impairment in mitochondrial respiration after light irradiation. Among others, [Ru(dppn)2phen](PF6)2 stands out for its very good IC50 values, correlated with a very high singlet oxygen quantum yield and mitochondrial respiration disruption.

Anisotropic dynamics of an interfacial enzyme active site observed using tethered substrate analogs and ultrafast 2D IR spectroscopy.

Enzymes accelerate the rates of biomolecular reactions by many orders of magnitude compared to bulk solution, and it is widely understood that this catalytic effect arises from a combination of polar pre-organization and electrostatic transition state stabilization. A number of recent reports have also implicated ultrafast (femtosecond-picosecond) timescale motions in enzymatic activity. However, complications arising from spatially-distributed disorder, the occurrence of multiple substrate binding modes, and the influence of hydration dynamics on solvent-exposed active sites still confound many experimental studies. Here we use ultrafast two-dimensional infrared (2D IR) spectroscopy and covalently-tethered substrate analogs to examine dynamical properties of the promiscuous Pyrococcus horikoshii ene-reductase (PhENR) active site in two binding configurations mimicking proposed "inactive" and "reactive" Michaelis complexes. Spectral diffusion measurements of aryl-nitrile substrate analogs reveal an end-to-end tradeoff between fast (sub-ps) and slow (>5 ps) motions. Fermi resonant aryl-azide analogs that sense interactions of coupled oscillators are described. Lineshape and quantum beat analyses of these probes reveal characteristics that correlate with aryl-nitrile frequency fluctuation correlation functions parameters, demonstrating that this anisotropy is an intrinsic property of the water-exposed active site, where countervailing gradients of fast dynamics and disorder in the reactant ground state are maintained near the hydration interface. Our results suggest several plausible factors leading to state-selective rate enhancement and promiscuity in PhENR. This study also highlights a strategy to detect perturbations to vibrational modes outside the transparent window of the mid-IR spectrum, which may be extended to other macromolecular systems.

Identification of a convergent spinal neuron population that encodes itch.

Itch is a protective sensation that drives scratching. Although specific cell types have been proposed to underlie itch, the neural circuit basis for itch remains unclear. Here, we used two-photon Ca2+ imaging of the dorsal horn to visualize the neuronal populations that are activated by itch-inducing agents. We identify a convergent population of spinal neurons that is defined by the expression of GRPR. Moreover, we discover that itch is conveyed to the brain via GRPR-expressing spinal output neurons that target the lateral parabrachial nucleus. Further, we show that nalfurafine, a clinically effective kappa opioid receptor agonist, relieves itch by inhibiting GRPR spinoparabrachial neurons. Finally, we demonstrate that a subset of GRPR spinal neurons show persistent, cell-intrinsic Ca2+ oscillations. These experiments provide the first population-level view of the spinal neurons that respond to pruritic stimuli, pinpoint the output neurons that convey itch to the brain, and identify the cellular target of kappa opioid receptor agonists for the inhibition of itch.

Intrinsic Homeostatic Plasticity in Mouse and Human Sensory Neurons.

In response to changes in activity induced by environmental cues, neurons in the central nervous system undergo homeostatic plasticity to sustain overall network function during abrupt changes in synaptic strengths. Homeostatic plasticity involves changes in synaptic scaling and regulation of intrinsic excitability. Increases in spontaneous firing and excitability of sensory neurons are evident in some forms of chronic pain in animal models and human patients. However, whether mechanisms of homeostatic plasticity are engaged in sensory neurons under normal conditions or altered after chronic pain is unknown. Here, we showed that sustained depolarization induced by 30mM KCl induces a compensatory decrease in the excitability in mouse and human sensory neurons. Moreover, voltage-gated sodium currents are robustly reduced in mouse sensory neurons contributing to the overall decrease in neuronal excitability. Decreased efficacy of these homeostatic mechanisms could potentially contribute to the development of the pathophysiology of chronic pain.

The Drosophila drop-dead gene is required for eggshell integrity.

The eggshell of the fruit fly Drosophila melanogaster is a useful model for understanding the synthesis of a complex extracellular matrix. The eggshell is synthesized during mid-to-late oogenesis by the somatic follicle cells that surround the developing oocyte. We previously reported that female flies mutant for the gene drop-dead ( drd ) are sterile, but the underlying cause of the sterility remained unknown. In this study, we examined the role of drd in eggshell synthesis. We show that eggs laid by drd mutant females are fertilized but arrest early in embryogenesis, and that the innermost layer of the eggshell, the vitelline membrane, is abnormally permeable to dye in these eggs. In addition, the major vitelline membrane proteins fail to become crosslinked by nonreducible bonds, a process that normally occurs during egg activation following ovulation, as evidenced by their solubility and detection by Western blot in laid eggs. In contrast, the Cp36 protein, which is found in the outer chorion layers of the eggshell, becomes crosslinked normally. To link the drd expression pattern with these phenotypes, we show that drd is expressed in the ovarian follicle cells beginning in mid-oogenesis, and, importantly, that all drd mutant eggshell phenotypes could be recapitulated by selective knockdown of drd expression in the follicle cells. To determine whether drd expression was required for the crosslinking itself, we performed in vitro activation and crosslinking experiments. The vitelline membranes of control egg chambers could become crosslinked either by incubation in hyperosmotic medium, which activates the egg chambers, or by exogenous peroxidase and hydrogen peroxide. In contrast, neither treatment resulted in the crosslinking of the vitelline membrane in drd mutant egg chambers. These results indicate that drd expression in the follicle cells is necessary for vitelline membrane proteins to serve as substrates for peroxidase-mediated cross-linking at the end of oogenesis.

Cell type-specific calcium imaging of central sensitization in mouse dorsal horn.

Allodynia is a state in which pain is elicited by innocuous stimuli. Capsaicin applied to the skin results in an allodynia that extends to a broad region beyond the application site. This sensitization is thought to be mediated by spinal networks; however, we do not have a clear picture of which spinal neurons mediate this phenomenon. To address this gap, we used two-photon calcium imaging of excitatory interneurons and spinal projection neurons in the mouse spinal dorsal horn. To distinguish among neuronal subtypes, we developed CICADA, a cell profiling approach to identify cell types during calcium imaging. We then identified capsaicin-responsive and capsaicin-sensitized neuronal populations. Capsaicin-sensitized neurons showed emergent responses to innocuous input and increased receptive field sizes consistent with psychophysical reports. Finally, we identified spinal output neurons that showed enhanced responses from innocuous input. These experiments provide a population-level view of central sensitization and a framework with which to model somatosensory integration in the dorsal horn.

Laboratory testing and antihypertensive medication adherence following initial treatment of incident, uncomplicated hypertension: A real-world data analysis.

In this study on medication adherence among newly diagnosed patients with uncomplicated, incident hypertension, we conducted a retrospective cohort study using available administrative and laboratory data from April 1, 2012 to March 31, 2017 in Alberta, Canada to understand the extent to which baseline laboratory assessment and/or subsequent follow-up was associated with persistence with antihypertensive therapy. We determined the frequency of baseline and follow-up testing and compared the rates of medication persistence by patient-, neighbourhood-, and treatment-related factors. Of 103 232 patients with newly diagnosed, uncomplicated hypertension who filled their first prescription within our study timeframe, 52.5% were non-persistent within 6 months. Persistent patients were more often female and residing in neighbourhoods with higher social status (with exception to rurality). Aside from older age, the strongest predictor of persistence was performance of laboratory testing related to hypertension with an apparent effect in which higher levels of medication persistence were seen with more frequent laboratory testing. We concluded that medication persistence was far from optimal, dropping off considerably after 6 months for more than half of patients. Medication persistence is a substantial barrier to realizing the full societal benefits of antihypertensive treatment. Ongoing follow up with patients, including laboratory testing, may be a critical component of better long term treatment persistence.

The polarization dependence of 2D IR cross-peaks distinguishes parallel-stranded and antiparallel-stranded DNA G-quadruplexes.

Guanine-rich nucleic acid sequences have a tendency to form four-stranded non-canonical motifs known as G-quadruplexes. These motifs may adopt a wide range of structures characterized by size, strand orientation, guanine base conformation, and fold topology. Using three K+-bound model systems, we show that vibrational coupling between guanine C6 = O and ring modes varies between parallel-stranded and antiparallel-stranded G-quadruplexes, and that such structures can be distinguished by comparison of the polarization dependences of cross-peaks in their two-dimensional infrared (2D IR) spectra. Combined with previously defined vibrational frequency trends, this analysis reveals key features of a 30-nucleotide unimolecular variant of the Bcl-2 proximal promoter that are consistent with its reported structure. This study shows that 2D IR spectroscopy is a convenient method for analyzing G-quadruplex structures that can be applied to complex sequences where traditional high-resolution methods are limited by solubility and disorder.

COVID-19 infection among international travellers: a prospective analysis.

OBJECTIVES: This report estimates the risk of COVID-19 importation and secondary transmission associated with a modified quarantine programme in Canada. DESIGN AND PARTICIPANTS: Prospective analysis of international asymptomatic travellers entering Alberta, Canada. INTERVENTIONS: All participants were required to receive a PCR COVID-19 test on arrival. If negative, participants could leave quarantine but were required to have a second test 6 or 7 days after arrival. If the arrival test was positive, participants were required to remain in quarantine for 14 days. MAIN OUTCOME MEASURES: Proportion and rate of participants testing positive for COVID-19; number of cases of secondary transmission. RESULTS: The analysis included 9535 international travellers entering Alberta by air (N=8398) or land (N=1137) that voluntarily enrolled in the Alberta Border Testing Pilot Programme (a subset of all travellers); most (83.1%) were Canadian citizens. Among the 9310 participants who received at least one test, 200 (21.5 per 1000, 95% CI 18.6 to 24.6) tested positive. Sixty-nine per cent (138/200) of positive tests were detected on arrival (14.8 per 1000 travellers, 95% CI 12.5 to 17.5). 62 cases (6.7 per 1000 travellers, 95% CI 5.1 to 8.5; 31.0% of positive cases) were identified among participants that had been released from quarantine following a negative test result on arrival. Of 192 participants who developed symptoms, 51 (26.6%) tested positive after arrival. Among participants with positive tests, four (2.0%) were hospitalised for COVID-19; none required critical care or died. Contact tracing among participants who tested positive identified 200 contacts; of 88 contacts tested, 22 were cases of secondary transmission (14 from those testing positive on arrival and 8 from those testing positive thereafter). SARS-CoV-2 B.1.1.7 lineage was not detected in any of the 200 positive cases. CONCLUSIONS: 21.5 per 1000 international travellers tested positive for COVID-19. Most (69%) tested positive on arrival and 31% tested positive during follow-up. These findings suggest the need for ongoing vigilance in travellers testing negative on arrival and highlight the value of follow-up testing and contact tracing to monitor and limit secondary transmission where possible.