Medication-wide association studies.

Undiscovered side effects of drugs can have a profound effect on the health of the nation, and electronic health-care databases offer opportunities to speed up the discovery of these side effects. We applied a "medication-wide association study" approach that combined multivariate analysis with exploratory visualization to study four health outcomes of interest in an administrative claims database of 46 million patients and a clinical database of 11 million patients. The technique had good predictive value, but there was no threshold high enough to eliminate false-positive findings.

Comparison of back pain prognostic risk stratification item sets.

Unlabelled: Back pain outcomes may be improved and costs lowered through risk-stratified care, but relative performance of alternative item sets for predicting back pain outcomes has not been well characterized. We compared alternative prognostic item sets based on STarT Back and Chronic Pain Risk screeners in a cohort of patients initiating primary care for back pain. The STarT Back item set was brief and relied on binary responses, whereas the Chronic Pain Risk item set employed scaled responses and assessed pain persistence and diffuse pain.

Dendronized organoplatinum(II) metallacyclic polymers constructed by hierarchical coordination-driven self-assembly and hydrogen-bonding interfaces.

We describe the efficient preparation of rhomboidal metallacycles that self-assemble upon mixing a donor decorated with 2-ureido-4-pyrimidinone (UPy) with acceptors containing pendant [G1]-[G3] dendrons. The formed rhomboids subsequently polymerize into dendronized organoplatinum(II) metallacyclic polymers through H-bonding UPy interfaces, which possess the structural features of conventional dendronized polymers as well as the dynamic reversibility of supramolecular polymers. Preservation of both properties in a single material is achieved by exploiting hierarchical self-assembly, namely the unification of coordination-driven self-assembly with H-bonding, which provides facile routes to dendronized metallacycles and subsequent high ordering.

A comparison of the empirical performance of methods for a risk identification system.

Background: Observational healthcare data offer the potential to enable identification of risks of medical products, and the medical literature is replete with analyses that aim to accomplish this objective. A number of established analytic methods dominate the literature but their operating characteristics in real-world settings remain unknown.

Objectives: To compare the performance of seven methods (new user cohort, case control, self-controlled case series, self-controlled cohort, disproportionality analysis, temporal pattern discovery, and longitudinal gamma poisson shrinker) as tools for risk identification in observational healthcare data.

Managing data quality for a drug safety surveillance system.

Objective: The objective of this study is to present a data quality assurance program for disparate data sources loaded into a Common Data Model, highlight data quality issues identified and resolutions implemented.

Background: The Observational Medical Outcomes Partnership is conducting methodological research to develop a system to monitor drug safety. Standard processes and tools are needed to ensure continuous data quality across a network of disparate databases, and to ensure that procedures used to extract-transform-load (ETL) processes maintain data integrity.

Variation in choice of study design: findings from the Epidemiology Design Decision Inventory and Evaluation (EDDIE) survey.

Background: Researchers using observational data to understand drug effects must make a number of analytic design choices that suit the characteristics of the data and the subject of the study. Review of the published literature suggests that there is a lack of consistency even when addressing the same research question in the same database.

Objective: To characterize the degree of similarity or difference in the method and analysis choices made by observational database research experts when presented with research study scenarios.

Desideratum for evidence based epidemiology.

Background: There is great variation in choices of method and specific analytical details in epidemiological studies, resulting in widely varying results even when studying the same drug and outcome in the same database. Not only does this variation undermine the credibility of the research but it limits our ability to improve the methods.

Methods: In order to evaluate the performance of methods and analysis choices we used standard references and a literature review to identify 164 positive controls (drug-outcome pairs believed to represent true adverse drug reactions), and 234 negative controls (drug-outcome pairs for which we have confidence there is no direct causal relationship).

Supramolecular polymers with tunable topologies via hierarchical coordination-driven self-assembly and hydrogen bonding interfaces.

A powerful strategy to obtain complex supramolecular materials is the bottom-up construction of noncovalently bound materials by hierarchical self-assembly. This assembly process involves stepwise, uniform increases to the architectural complexity of a substrate, starting from discrete precursors and growing in dimensionality through controlled reactivity to a final product. Herein, two orthogonal processes are exploited: coordination-driven self-assembly and hydrogen bonding.

Tunable visible light emission of self-assembled rhomboidal metallacycles.

Supramolecular coordination complexes (SCCs) have been proposed for applications necessitating photon emitting properties; however, two critical characteristics, facile tunability and high emission quantum yields, have yet to be demonstrated on SCC platforms. Herein, a series of functionalized D2h [D2A2] rhomboids (D = 2,6-bis(4-ethynylpyridine)aniline-based ligands; A = 2,9-bis[trans-Pt(PEt3)2NO3]phenanthrene) is described with emission wavelengths spanning the visible region (λmax = 476-581 nm). Tuning was achieved by simple functional group modifications para to the aniline amine on the donor building block.

Hierarchical self-assembly: well-defined supramolecular nanostructures and metallohydrogels via amphiphilic discrete organoplatinum(II) metallacycles.

Metallacyclic cores provide a scaffold upon which pendant functionalities can be organized to direct the formation of dimensionally controllable nanostructures. Because of the modularity of coordination-driven self-assembly, the properties of a given supramolecular core can be readily tuned, which has a significant effect on the resulting nanostructured material. Herein we report the efficient preparation of two amphiphilic rhomboids that can subsequently order into 0D micelles, 1D nanofibers, or 2D nanoribbons.

Photophysical properties of endohedral amine-functionalized bis(phosphine) Pt(II) complexes as models for emissive metallacycles.

The photophysical properties of bis(phosphine) Pt(II) complexes constructed from 2,6-bis(pyrid-3-ylethynyl) aniline and 2,6-bis(pyrid-4-ylethynyl) aniline vary significantly, even though the complexes differ only in the position of the coordinating nitrogen. By capping the ligands with an aryl bis(phosphine) Pt(II) metal acceptor, the photophysical properties of the two isomeric systems were directly compared, revealing that the low-energy absorption and emission bands of the two systems were separated by 30 nm (1804 cm(-1)) and 39 nm (1692 cm(-1)), respectively. From the analysis of time-dependent density functional (TD-DFT) calculations and excited-state lifetime measurements, it was determined that the nature of the Pt-N bond in the HOMO and the sums of the radiative (k(rad)) and nonradiative (k(nr)) rate constants were significantly different in the two systems.

Validation of a population-based method to assess drug-induced alterations in the QT interval: a self-controlled crossover study.

Purpose: The purpose of this study was to ascertain, in the context of an integrated health care delivery system, the association between a comprehensive list of drugs known to have potential QT liability and QT prolongation or shortening.

Methods: By using a self-controlled crossover study with 59 467 subjects, we ascertained intra-individual change in log-linear regression-corrected QT (QTcreg ) during the period between 1995 and mid-2008 for 90 drugs while adjusting for age, gender, race/ethnicity, comorbid conditions, number of electrocardiograms (ECGs), and time between pre-ECG and post-ECG. The proportion of users of each drug-developing incident long QT was also estimated.

Anticancer potency and multidrug-resistant studies of self-assembled arene-ruthenium metallarectangles.

A suite of three tetraruthenium metallacycles have been obtained from [2+2] self-assemblies between N,N'-Di-(4-pyridyl)-1,4,5,8-naphthalenetetracarbo-xydiimide (4) and one of the three dinuclear arene ruthenium clips, (η(6)-p-iPrC6H4Me)2Ru2(OO∩OO)][OTf]2 (OO∩OO = oxalate 1, 2,5-dioxydo-1,4-benzoquinonato (dobq) 2, 5,8-dihydroxy-1,4-naphthaquinonato (donq) 3; OTf = triflate). All complexes were isolated in good yield (>85 %) as triflate salts and were fully characterized by using (1)H NMR and UV/Vis spectroscopies, and high-resolution electrospray mass spectrometry. A single crystal of the metallarectangle 5 was suitable for X-ray diffraction structural characterization.

Biomedical and biochemical applications of self-assembled metallacycles and metallacages.

Metal ions and metal complexes with organic molecules are ubiquitous in nature. Bulk metal ions of Na, K, Mg, and Ca constitute as much as 1% of human body weight. The remaining trace ions, most commonly of Fe, Ni, Cu, Mn, Zn, Co, Mo, and V, make up ∼0.

Multi-component coordination-driven self-assembly: construction of alkyl-based structures and molecular modelling.

The design of supramolecular coordination complexes (SCCs) is typically predicated on the use of rigid molecular building blocks through which the structural outcome is determined based on the number and orientation of labile coordination sites on metal acceptors, and the angularity of the ligand donors that are to bridge these nodes. Three-component systems extend the complexity of self-assembly by utilizing two different Lewis base donors in concert with a metal that favors a heteroligated coordination environment. The thermodynamic preference for heteroligation provides a new design principle to the formation of SCCs, wherein multicomponent architectures need not employ only rigid donors.

Understanding and assessing potential serious adverse events: a practical approach to understanding the benefits and harm of psoriasis treatments.

Background: Any therapeutic intervention carries with it the potential for benefit and harm. Generally, benefit is far more common than risk; however, risk aversion drives many of the treatment decisions made by patients and their physicians.

Objective: To provide guidelines to help clinicians improve their understanding of causality and the interpretation of harm.

Assessment of case definitions for identifying acute liver injury in large observational databases.

Background: Determining the aetiology of acute liver injury (ALI) may be challenging to both clinicians and researchers. Observational research is particularly useful in studying rare medical outcomes such as ALI; however, case definitions for ALI in previous observational studies lack consistency and sensitivity. ALI is a clinically important condition with various aetiologies, including drug exposure.

Evaluating the impact of database heterogeneity on observational study results.

Clinical studies that use observational databases to evaluate the effects of medical products have become commonplace. Such studies begin by selecting a particular database, a decision that published papers invariably report but do not discuss. Studies of the same issue in different databases, however, can and do generate different results, sometimes with strikingly different clinical implications.

Concentration-dependent supramolecular engineering of hydrogen-bonded nanostructures at surfaces: predicting self-assembly in 2D.

We report a joint computational and experimental study on the concentration-dependent self-assembly of a flat C3-symmetric molecule at surfaces. As a model system we have chosen a rigid molecular module, 1,3,5-tris(pyridine-4-ylethynyl)benzene, which can undergo self-association via hydrogen bonding (H-bonding) to form ordered 2D nanostructures. In particular, the lattice Monte Carlo method, combined with density functional calculations, was employed to explore the spontaneous supramolecular organization of this tripod-shaped molecule under surface confinement.

Growth Inhibitory Activity of a Bis-benzimidazole-Bridged Arene Ruthenium Metalla-Rectangle and Prism.

Two new supramolecular coordination complexes (SCCs), were obtained from the self-assembly of a new bis-benzimidazole bridged Ru acceptor, , with dipyridyl and tripyridyl donors, respectively. As part of a growing library of anticancer-active Ru-based SCCs, metalla-prism selectively showed high cytotoxicities relative to cisplatin for a series of cancer cell lines, with IC values as low as 8.41 μM for MCF7 cells, as determined from MTS assays.

Photophysical properties of self-assembled multinuclear platinum metallacycles with different conformational geometries.

In this work, spectroscopic techniques and quantum chemistry calculations were used to investigate the photophysical properties of various multinuclear platinum complexes with different conformational geometries. This suite of complexes includes a Pt-pyridyl square, a Pt-carboxylate triangle, and a mixed Pt-pyridyl-carboxylate rectangle, as well as two mononuclear Pt model complexes. Studying the individual molecular precursors in the context of larger assemblies is important to provide a complete understanding of the factors governing the observed photophysical properties of a given system.

Self-assembly of ambidentate pyridyl-carboxylate ligands with octahedral ruthenium metal centers: self-selection for a single-linkage isomer and anticancer-potency studies.

The synthesis of six new [2+2] metallarectangles through the coordination-driven self-assembly of octahedral Ru(II)-based acceptors with ambidentate pyridyl-carboxylate donors is described. These molecular rectangles are fully characterized by (1)H NMR spectroscopy, high-resolution electrospray mass spectrometry, and single-crystal X-ray diffraction. In each case, despite the possible formation of multiple isomers, based on the relative orientation of the pyridyl and carboxylate groups (head-to-head versus head-to-tail), evidence for the formation of a single preferred ensemble (head-to-tail) was found in the (1)H NMR spectra.

Formation of [3]catenanes from 10 precursors via multicomponent coordination-driven self-assembly of metallarectangles.

We describe the formation of a suite of [3]catenanes via multicomponent coordination-driven self-assembly and host-guest complexation of a rectangular scaffold comprising a 90° Pt-based acceptor building block with a pseudorotaxane bis(pyridinium)ethane/dibenzo-24-crown-8 linear dipyridyl ligand and three dicarboxylate donors. The doubly threaded [3]catenanes are formed from a total of 10 molecular components from four unique species. Furthermore, the dynamic catenation process is reversible and can be switched off and on in a controllable manner by successive addition of KPF(6) and 18-crown-6, as monitored by (1)H and (31)P NMR spectroscopy.