Development of the key performance indicators for digital health interventions: A scoping review.

Background: Digital health interventions offer new methods for delivering healthcare, with the potential to innovate healthcare services. Key performance indicators play a role in the evaluation, measurement, and improvement in healthcare quality and service performance. The aim of this scoping review was to identify current knowledge and evidence surrounding the development of key performance indicators for digital health interventions. Methods: A literature search was conducted across ten key databases: AMED - The Allied and Complementary Medicine Database, CINAHL - Complete, Health Source: Nursing/Academic Edition, MEDLINE, APA PsycINFO, EMBASE, EBM Reviews - Cochrane Database of Systematic Reviews, EBM Reviews - Database of Abstracts of Reviews of Effects, EBM Reviews - Health Technology Assessment, and IEEE Xplore. Results: Five references were eligible for the review. Two were articles on original research studies of a specific digital health intervention, and two were overviews of methods for developing digital health interventions (not specific to a single digital health intervention). All the included reports discussed the involvement of stakeholders in developing key performance indicators for digital health interventions. The step of identifying and defining the key performance indicators was completed using various methodologies, but all centred on a form of stakeholder involvement. Potential options for stakeholder involvement for key performance indicator identification include the use of an elicitation framework, a factorial survey approach, or a Delphi study. Conclusions: Few articles were identified, highlighting a significant gap in evidence-based knowledge in this domain. All the included articles discussed the involvement of stakeholders in developing key performance indicators for digital health interventions, which were performed using various methodologies. The articles acknowledged a lack of literature related to key performance indicator development for digital health interventions. To allow comparability between key performance indicator initiatives and facilitate work in the field, further research would be beneficial to develop a common methodology for key performance indicators development for digital health interventions.

Pre-microRNA binding aminoglycosides and antitumor drugs as inhibitors of Dicer catalyzed microRNA processing.

Over-expressions of miRNAs are being increasingly linked with many diseases including different types of cancer. In this study, the role of some known small molecular therapeutics has been investigated for their ability to bind with the pre-miRNA target (hsa-mir-155) and thereby to interfere with the Dicer catalyzed miRNA processing. Potential binding and inhibition effects have been demonstrated by some of these analogs. They can be used as leads for further development of potent small molecular miRNA-antagonists.

Structural and binding study of modified siRNAs with the Argonaute 2 PAZ domain by NMR spectroscopy.

By using high-resolution NMR spectroscopy, the structures of a natural short interfering RNA (siRNA) and of several altritol nucleic acid (ANA)-modified siRNAs were determined. The interaction of modified siRNAs with the PAZ domain of the Argonaute 2 protein of Drosophila melanogaster was also studied. The structures show that the modified siRNA duplexes (ANA/RNA) adopt a geometry very similar to the naturally occurring A-type siRNA duplex. All ribose residues, except for the 3' overhang, show 3'-endo conformation. The six-membered altritol sugar in ANA occurs in a chair conformation with the nucleobase in an axial position. In all siRNA duplexes, two overhanging nucleotides at the 3' end enhance the stability of the first neighboring base pair by a stacking interaction. The first overhanging nucleotide has a rather fixed position, whereas the second overhanging nucleotide shows larger flexibility. NMR binding studies of the PAZ domain with ANA-modified siRNAs demonstrate that modifications in the double-stranded region of the antisense strand have some small effects on the binding affinity as compared with the unmodified siRNA. Modification of the 3' overhang with thymidine (dTdT) residues shows a sixfold increase in the binding affinity compared with the unmodified siRNA (relative binding affinity of 17% compared with dTdT-modified overhang), whereas modification of the 3' overhang with ANA largely decreases the binding affinity.

Comparison of the complexation between methylprednisolone and different cyclodextrins in solution by 1H-NMR and molecular modeling studies.

Complexation in solution between methylprednisolone and three different cyclodextrins [2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD), gamma-cyclodextrin (gamma-CD), and 2-hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD)] was studied using phase solubility analysis, one and two-dimensional (1)H-NMR and molecular modeling. Estimates of the complex formation constant (K(1:1)) show that the tendency of methylprednisolone to complex with CDs follows the order: gamma-CD > HP-gamma-CD > HP-beta-CD. The large variation of chemical shifts from protons located around the interior of the hydrophobic cavity (H-3', H-5', and H-6') coupled with minimal variation of shifts from protons located on the outer sphere of gamma-CD (H-1', H-2', and H-4') provided clear evidence of inclusion complexation. The molecular modeling study, indicated inclusion complexation between methylprednisolone and gamma-CD and HP-gamma-CD by entrance of the A and B rings of methylprednisolone into the CD cavity from its bigger rim. For the methylprednisolone: HP-beta-CD complex, the molecular modeling study could not be carried out; hence, two possibilities of complex formation are proposed: (1) methylprednisolone enters HP-beta-CD from the wider rim by its D and C ring, (2) the A and B ring of methylprednisolone enters deeper in to the CD cavity so that a part of the A ring of steroidal structure is outside of the cavity.

Structure determination of the top-loop of the conserved 3'-terminal secondary structure in the genome of flaviviruses.

To what extent small differences in RNA sequences (mutations) can have a profound impact on biology remains an intriguing question. This effect can be studied by using untranslated RNA regions as a model. We have studied the influence of mutations on the structure of an RNA hairpin that occurs in the 3'-untranslated region (UTR) of Flaviviridae, and is known to have a large impact on the vector dependency of flaviviruses. Three related RNA sequences were studied by NMR spectroscopy. The selected sequences represent each one of the three clusters in the flavivirus genes (mosquito-borne, tick-borne, and no-known-vector viruses). A new strategy was used to obtain chemical shift signatures of carbonyl atoms in unlabeled uridine nucleobases to characterize their involvement in hydrogen bonding. Clear differences occur in the structures and stacking pattern of the three RNA hairpins. The observed differences cannot be predicted based on sequence analysis. A different biology can be correlated with a different RNA tertiary structure. The underlying biological mechanism, however, remains to be studied.

Self-complementary sequence context in mature miRNAs.

MicroRNAs (miRNAs) are a class of 19-25 nt long non-coding RNAs that regulate gene expression post-transcriptionally by binding with partially complementary sequences in the 3'-untranslated region (3'-UTR) and inhibiting mRNA translation or by affecting mRNA stability. We have characterized the structures and the equilibrium between hairpin and homo-duplex form of the mature strand of hsa-mir-520h by various concentration and temperature dependent 1D, 2D NMR experiments and those structures correspond well with Mfold-folded and UNAFold-aligned secondary structures. A detailed folding and alignment analysis in physiological conditions of all mature miRNA strands from the complete database of known miRNAs (miRBase) was performed. The statistical analysis of the resulting folding and alignment data showed for the first time the potential of a large number of mature miRNAs to form significant hairpin and/or homo-duplex structures in solution. The self-complementarity of mature miRNAs can provide a mechanistic tuning and a regulatory sophistication to the process of miRNA mediated gene regulation.

Structural characterization and biological evaluation of small interfering RNAs containing cyclohexenyl nucleosides.

CeNA is an oligonucleotide where the (deoxy)ribose sugars have been replaced by cyclohexenyl moieties. We have determined the NMR structure of a CeNA:RNA duplex and have modeled this duplex in the crystal structure of a PIWI protein. An N puckering of the ribose nucleosides, a 2H3 conformation of the cyclohexenyl nucleosides, and an A-like helix conformation of the backbone, which deviates from the standard A-type helix by a larger twist and a smaller slide, are observed. The model of the CeNA:RNA duplex bound to the PIWI protein does not show major differences in the interaction of the guide CeNA with the protein when compared with dsRNA, suggesting that CeNA modified oligonucleotides might be useful as siRNAs. Incorporation of one or two CeNA units in the sense or antisense strands of dsRNA led to similar or enhanced activity compared to unmodified siRNAs. This was tested by targeting inhibition of expression of the MDR1 gene with accompanying changes in P-glycoprotein expression, drug transport, and drug resistance.

Structure of the alpha-homo-DNA:RNA duplex and the function of twist and slide to catalogue nucleic acid duplexes.

High-resolution NMR studies of an alpha-homo-DNA:RNA duplex reveal the formation of a right-handed parallel-oriented helix. It differs significantly from a standard A- or B-type helix by a small twist value (26.2 degrees ), which leads to a helical pitch of 13.7 base pairs per helical turn, a negative inclination (-1.78 Angstrom) and a large x displacement (5.90 Angstrom). The rise (3.4 Angstrom) is similar to that found in B-DNA. The solution of this new helix structure has stimulated us to develop a mathematical and geometrical model based on slide and twist parameters to describe nucleic acid duplexes. All existing duplexes can be positioned within this landscape, which can be used to understand the helicalization process.

Base-base interactions in the minor groove of double-stranded DNA.

A method has been developed for the synthesis of bisheaded nucleosides with thymine and adenine base moieties. We have demonstrated that, when incorporated in oligonucleotides, extrahelical A-T base interactions are possible when the bisheaded nucleosides are positioned in opposite strands of the duplex and are separated from each other by one regular base pair.

The naturally occurring N6-threonyl adenine in anticodon loop of Schizosaccharomyces pombe tRNAi causes formation of a unique U-turn motif.

Modified nucleosides play an important role in structure and function of tRNA. We have determined the solution structure of the anticodon stem-loop (ASL) of initiator tRNA of Schizosaccharomyces pombe. The incorporation of N6-threonylcarbamoyladenosine at the position 3' to the anticodon triplet (t6A37) results in the formation of a U-turn motif and enhances stacking interactions within the loop and stem regions (i.e. between A35 and t6A37) by bulging out U36. This conformation was not observed in a crystal structure of tRNAi including the same modification in its anticodon loop, nor in the solution structure of the unmodified ASL. A t6A modification also occurs in the well studied anti-stem-loop of lys-tRNA(UUU). A comparison of this stem-loop with our structure demonstrates different effects of the modification depending on the loop sequence.

Synthesis and conformational analysis of a ribo-type cyclohexenyl nucleoside.

A straightforward approach to a novel class of ribo-type cyclohexenyl nucleosides is described. An electron-demand Diels-Alder reaction forms the key-step of the chosen synthetic pathway. Although the difference is small, conformational analysis using NMR shows that this nucleoside analogue adopts preferentially an 2H3 conformation (S-type), while the "deoxy" cyclohexenyl analogue has a preference for a C3' endo conformation (N-type). Analyses of the conformational equilibrium reveal that, in the given experimental conditions, the difference between adenosine and its cyclohexenyl congener resides in their different DeltaG values; furthermore, in adenosine, the conformational preference is of enthalpic origin, whereas in the cyclohexenyl congener, the conformational preference is of entropic origin.

Cyclohexenyl nucleic acids: conformationally flexible oligonucleotides.

Cyclohexenyl nucleic acid (CeNA) is a nucleic acid mimic, where the (deoxy)ribose sugar has been replaced by cyclohexenyl moieties. In order to study the conformation of cyclohexenyl nucleosides by NMR, the HexRot program was developed to calculate conformations from scalar coupling constants of cyclohexenyl compounds, analogous to the methods applied for (deoxy)ribose nucleosides. The conformational equilibria and the values of the thermodynamic parameters are very similar between a cyclohexenyl nucleoside [energy difference between 2H3 (N-type) and 2H3 (S-type) is 1.8 kJ/mol and equilibrium occurs via the eastern hemisphere with a barrier of 10.9 kJ/mol] and a natural ribose nucleoside (energy difference between N-type and S-type is 2 kJ/mol and equilibrium occurs via the eastern hemisphere with a barrier of 4-20 kJ/mol). The flexibility of the cyclohexenyl nucleoside was demonstrated by the fast equilibrium between two conformational states that was observed in a CeNA-U monomer, combined with the 2H3 conformation of the cyclohexene moiety when incorporated into a Dickerson dodecamer and the 2H3 conformation when incorporated in a d(5'-GCGT*GCG-3')/d(5'-CGCACGC-3') duplex, as determined by the NMR spectroscopy. This represents the first example of a synthetic nucleoside that adopts different conformations when incorporated in different double-stranded DNA sequences.

Cleavage of DNA without loss of genetic information by incorporation of a disaccharide nucleoside.

A ribose residue inserted between the 3'-OH of one nucleotide and the 5'-phosphate group of the next nucleotide, functions as a site-specific cleavage site within DNA. This extra ribose does not interrupt helix formation and it protects duplex DNA against cleavage by restriction enzymes. Cleavage can be obtained with periodate and all ribose fragments can be removed with sodium hydroxide. As a result of this, an intact natural oligodeoxynucleotide is obtained after ligation reaction, which means that site-specific cleavage and recovering of intact DNA occurs without loss of genetic information.

Synthesis and conformational properties of O-beta-D-ribofuranosyl-(1''-2')-guanosine and (adenosine)-5''-phosphate.

The efficient synthesis of Grp and Arp, minor tRNA components, has been developed.

Synthesis and properties of phosphorylated 3'-O-beta-D-ribofuranosyl-2'-deoxythymidine.

A strategy was developed for the synthesis of 3'-O-beta-D-ribofuranosyl 2'-deoxythymidine derivatives using three different protecting groups, which allows the synthesis of a phosphoramidite building block for oligonucleotide synthesis. Likewise the 5'-O- and 5''-O-phosphorylated analogues were synthesized and their conformation was determined using NMR spectroscopy.