Social and Structural Drivers of Health and Transition to Adult Care

CONTEXT

Youth with chronic health conditions experience challenges during their transition to adult care. Those with marginalized identities likely experience further disparities in care as they navigate structural barriers throughout transition.

OBJECTIVES

This scoping review aims to identify the social and structural drivers of health (SSDOH) associated with outcomes for youth transitioning to adult care, particularly those who experience structural marginalization, including Black, Indigenous, and 2-spirit, lesbian, gay, bisexual, transgender, queer or questioning, and others youth.

DATA SOURCES

Medline, Embase, CINAHL, and PsycINFO were searched from earliest available date to May 2022.

STUDY SELECTION

Two reviewers screened titles and abstracts, followed by full-text. Disagreements were resolved by a third reviewer. Primary research studying the association between SSDOH and transition outcomes were included.

DATA EXTRACTION

SSDOH were subcategorized as social drivers, structural drivers, and demographic characteristics. Transition outcomes were classified into themes. Associations between SSDOH and outcomes were assessed according to their statistical significance and were categorized into significant (P < .05), nonsignificant (P > .05), and unclear significance.

RESULTS

101 studies were included, identifying 12 social drivers (childhood environment, income, education, employment, health literacy, insurance, geographic location, language, immigration, food security, psychosocial stressors, and stigma) and 5 demographic characteristics (race and ethnicity, gender, illness type, illness severity, and comorbidity). No structural drivers were studied. Gender was significantly associated with communication, quality of life, transfer satisfaction, transfer completion, and transfer timing, and race and ethnicity with appointment keeping and transfer completion.

LIMITATIONS

Studies were heterogeneous and a meta-analysis was not possible.

CONCLUSIONS

Gender and race and ethnicity are associated with inequities in transition outcomes. Understanding these associations is crucial in informing transition interventions and mitigating health inequities.

POS0678 DOES SILDENAFIL IMPROVE ENDOTHELIAL DYSFUNCTION IN RHEUMATOID ARTHRITIS? – A PILOT CLINICAL TRIAL

Background:

Rheumatoid arthritis (RA) is independently associated with an increased risk of cardiovascular disease (CVD). One of the early stages of atherosclerosis is endothelial dysfunction, which is increased in RA. Using drugs to target endothelial dysfunction is a promising novel strategy for CVD prevention in RA. Sildenafil has been shown to improve endothelial function in diabetics, who have similar increased CVD risk. Our hypothesis was that sildenafil use may be a novel primary CVD prevention strategy in RA.

Objectives:

To determine if sildenafil use in RA patients improves endothelial dysfunction (as measured by brachial artery flow-mediated dilation [FMD] and peripheral arterial tone [PAT]), as well as serum inflammatory and atherosclerosis biomarkers.

Methods:

This NIH-funded study was a phase II, randomized double-blind placebo-controlled crossover efficacy trial of 25 RA patients, with no known history of CVD, but at least one traditional CVD risk factor. Patients were randomized 1:1 to receive either sildenafil or placebo for 3 months, then after a 2-week washout, crossed over to each respective group for an additional 3 months. Vascular studies (FMD and PAT) and serum atherosclerosis biomarkers (e-Selectin, ICAM-1, VCAM-1) were performed at baseline, 3 months pre- and post-washout, and 6 months. Adverse events were collected. Given the cross-over design, analyses included a random effects model for within-subject comparisons of sildenafil versus placebo periods, adjusting for the baseline (FMD or EndoPAT) within that period and a term for treatment order. All tests were 2-sided with α=0.05.

Results:

A total of 233 subjects were assessed for eligibility, with 25 subjects being randomized after written informed consent. A total of 13 subjects were randomized to placebo first, and 12 to sildenafil first. Baseline characteristics were similar between those randomized to Placebo vs. Sildenafil first. Mean age was 62.0+/-10.9 years; 84% were female; and 92% were white. A total of 6 adverse events experienced in 3 subjects occurred. The primary endpoint (increase in %FMD in Sildenafil period vs. Placebo period) was not significant (p=0.19). However, note the study was powered at 80% to detect an effect size of 0.37 for change in %FMD or biomarker with a sample size of 60, not 25. However, sildenafil use was associated with a significant increase (improvement) by 0.200 units of PAT ratio (p=0.003) compared with placebo, adjusted by treatment order and baseline PAT ratio (within the given treatment period). Exploratory linear mixed models comparing e-Selectin, ICAM-1, and VCAM-1 between Sildenafil vs. Placebo periods, adjusted for treatment order and the baseline biomarker level, did not show any significant differences except for ICAM-1 (55.3 units higher in Sildenafil vs. Placebo periods, p=0.011).

Conclusion:

In this pilot trial of 25 RA subjects, sildenafil use was associated with a significant increase (improvement) in endothelial function as measured by PAT. However, there was no significant difference in FMD. The study is limited due to the small sample size, which was impacted by slow recruitment as well as the COVID-19 pandemic. Future larger studies are required to assess whether other PDE5 inhibitors may improve endothelial dysfunction in RA and other autoimmune disease patients at high risk of CVD.

References:

[1]Maradit-Kremers H, Crowson CS, Nicola PJ, et al. Increased unrecognized coronary heart disease and sudden deaths in rheumatoid arthritis: a population-based cohort study. Arthritis Rheum 2005;52:402-11.

[2]Peters MJ, van Halm VP, Voskuyl AE, et al. Does rheumatoid arthritis equal diabetes mellitus as an independent risk factor for cardiovascular disease? A prospective study. Arthritis Rheum 2009;61:1571-9.

[3]Deyoung L, Chung E, Kovac JR, et al. Daily use of sildenafil improves endothelial function in men with type 2 diabetes. J Andrology 2012;33:176-80.

Disclosure of Interests:

None declared

Pico-Salax versus polyethylene glycol for bowel cleanout before colonoscopy in children: a randomized controlled trial

BACKGROUND AND STUDY AIMS

Comparison of bowel preparation for colonoscopy in children with either Pico-Salax (sodium picosulphate with magnesium citrate) or polyethylene glycol with electrolyte solution (PEG-ELS).

PATIENTS AND METHODS

In this investigator-blinded, randomized controlled trial, 83 children (12.5 +/- 3.1 years) requiring elective colonoscopy at a referral hospital were randomly allocated to Pico-Salax (n = 43) or PEG-ELS (n = 40), and an intention-to treat analysis was applied. Pico-Salax was administered in two doses, one the evening before and one on the morning of the procedure. PEG-ELS was administered over 4 hours. Efficacy was scored using the Ottawa scale and other constructs. Tolerability and toxicity were measured by patient and nursing questionnaires and serum biochemistry.

RESULTS

35 of Pico-Salax patients (81 %) were satisfied or very satisfied with the cleanout, compared with 19 (48 %) in the PEG-ELS group (P = 0.001). No differences were found in bowel cleanout effectiveness, as judged by the Ottawa score (P = 0.24), completion rates (P = 0.69), colonoscopy duration (P = 0.59), need for enemas (P = 0.25), or physician's global impression (P = 0.7). Except for one case of mild dehydration in the Pico-Salax group, no clinically significant adverse events were recorded. Serum biochemistry results were similar between groups except for more hypermagnesemia associated with Pico-Salax and hypokalemia with PEG-ELS; neither was clinically significant.

CONCLUSION

Children tolerate Pico-Salax better than PEG-ELS for bowel cleanout before colonoscopy. This study did not demonstrate superiority of effectiveness or safety for either regimen.

Identifying nursing research priorities: general and neuroscience specific at an acute care hospital

As a result of economic and health care changes the role of the nurse continues to expand and research-based practice is changing its focus. Limited resources and staff shortages have revealed new areas for research study. Clinical nurses have valuable questions to share that can form the basis of future nursing research. The purposes of the study were to: (a) Determine the priorities for nursing research within a single acute care teaching hospital; (b) Promote nurses' awareness of the importance of research-based practice; (c) Facilitate the development of future nursing research. It was assumed that nurses who carry out direct and indirect patient care roles are "experts" and therefore, are in a position to identify what they see as important questions and in need of further investigation. Three hundred and sixty-six nurses (24%) responded to round #1 of the open ended survey and submitted a total of 912 clinical practice issues. Initially, issues were broadly categorized into clinical and indirect clinical themes in a series of subcategories. Round #2 was conducted to identify nurses' ratings of the priority of the final 123 research issues for future clinical research and practice improvement efforts. Results of the two rounds will be presented, including issues identified by neuroscience nurses. This information will provide a valuable source for additional neuroscience research at either the local or international level.

Structural and geometrical constraints on the outer dynein arm in situ

This study considers the relationship between two structural forms of the 22S dynein arm of Tetrahymena thermophila: the bouquet and the compact arm. The compact arm differs from the bouquet and from other proposed forms (e.g., the "toadstool") in that the globular domains are situated transversely across the interdoublet gap with one globular subunit, the head, proximal to the adjacent doublet microtubule. The other models place all three globular domains proximal to the neighboring doublet microtubule. When sliding of an isolated axoneme is induced, at least 57% of total attached arms on exposed doublets are in the compact form within dimensions of 24 x 24 x 12 nm, and only about 2% of the arms are bouquets. Toadstools are incompatible with the images seen. Bouquets are not found in regions of the doublet protected by a neighboring doublet. When axonemes with exposed doublets are treated with 0.5 M KCl for 30 min, the compact arms and the dynein heavy (H)-chains disappear, while isolated bouquets and dynein H-chains appear in the medium, suggesting that the compact arms give rise to the bouquets as they are solubilized. The bouquet is the predominant form of isolated 22S dynein molecules, which are found in two apparently enantiomorphic forms, within dimensions 45 x 39 x 13 nm; bouquets attached to doublets have dimensions similar to those of isolated bouquets. Computer modeling indicates that in an intact standard-diameter axoneme, these dimensions are incompatible with the interdoublet volume available for an arm; the bouquet therefore represents an unfolded compact arm. A plausible sequence of changes can be modeled to illustrate the conversion of an attached compact arm to an attached and then free bouquet. The toadstool is probably an artifact that arises after unfolding. Consistent with the conformational difference, H-chains of attached compact arms differ from those of isolated bouquets in their susceptibility to limited proteolysis. These results suggest that the compact arm, rather than the unfolded bouquet or the toadstool, is the functional form of the outer arm in the intact axoneme.

Computer modelling of Tetrahymena axonemes at macromolecular resolution. Interpretation of electron micrographs

A computer-generated model of the structural arrangement of the complete 9+2 ciliary axoneme of Tetrahymena at macromolecular resolution (4 nm) is presented. The model reconciles detailed information about subcomponents from negative-stained, thin-section and freeze-fracture electron micrographs, integrating the images into a consistent three-dimensional picture. This illuminates problems such as the requirement for compaction of dynein to form the arm, difficulties in visualization of the circumferential links, construction of the central sheath, and the comparative periodicities of the inner and outer arms. The model is pragmatic in that it is flexible and easily changed, as new information becomes available. It is also useful in the development of dynamic concepts, such as a spatial description of the dynein cross-bridge cycle, which is illustrated, or relationships between adjacent doublets during sliding and bending.

Dynein arm attachment probed with a non-hydrolyzable ATP analog. Structural evidence for patterns of activity

The dynein arms that power ciliary motility are normally permanently attached by one end exclusively to subfiber A of each axonemal doublet (N) while the other (head) end transiently attaches to the subfiber B of the adjacent doublet (N + 1) to produce sliding of the doublets. In Tetrahymena axonemes, sliding of contiguous groups of doublets is induced by ATP suggesting that, in the absence of exogenous protease, there may be sets of potentially active and potentially inactive or refractory arms in a single axoneme. In the presence of a non-hydrolyzable analog of ATP, beta,gamma-methylene adenosine 5'-triphosphate (AMP-PCP), about half the doublets in an axonemal preparation retain all arms bound to subfiber A, but half the doublets show long regions where some arms are pulled away from subfiber A of doublet N and attached to subfiber B of doublet N + 1 by their head ends. In AMP-PCP-induced splaying, positional information regarding arm state is retained. Analysis reveals that throughout regions where B subfiber attachment is found, small groups of about four subfiber B attached arms alternate with groups of about four arms that remain attached to subfiber A. This unique pattern of attachment suggests that arms function co-operatively in groups of four. Further, the repetition of the pattern is reminiscent of metachronal activity seen at higher levels of biological organization. This suggests that in these regions we have instantaneously preserved groups of arms capable of attaching to and detaching from doublet N + 1 in rapid succession. This appearance could be used to delineate the potentially active sets of arm, primed for mechanochemical activity, within an axoneme.

Structures attached to doublet microtubules of cilia: computer modeling of thin-section and negative-stain stereo images

With a single set of positional coordinates for longitudinal and transverse attachment of the inner and outer rows of dynein arms with respect to the doublet microtubules of Tetrahymena ciliary axonemes, a computer model has been constructed at 4-nm resolution that reconciles negative-stain en face stereo images of arm and spoke positions to traditional images of tannic acid/glutaraldehyde-fixed sections. In this model, inner and outer arms correspond in substructure; both repeat with a 24-nm periodicity without stagger between rows, and a pair of arms is in exact alignment with the first spoke (S1) in each doublet spoke group. The model and the supporting micrographs suggest that each arm cycles in three dimensions and that, during cycling, the inner and outer arms move in opposite directions with respect to the center of subfiber A of the doublet (N). Attachment is off-center with respect to subfiber B of the adjacent doublet (N + 1), causing the sliding doublets to skew with respect to one another.

The cytoskeleton of the apical border of the lateral cells of freshwater mussel gill: structural integration of microtubule and actin filament-based organelles

The coexistence of densely packed microtubule- and microfilament-based elements in the apex of ciliated epithelial cells, such as the lateral (L) cells of freshwater mussel gill, suggests that with this system it may be possible to define structural connections and interactions that permit integrated cytoskeletal responses to known physiological stimuli. In this study we examine the structure of the L cell apex in detail. The central elements of the elaborate cytoskeleton of the cortex are the basal bodies whose specialized accessory processes are points of integration and the focus of cortical microtubule and microfilament networks. Each basal body supports a cilium and interacts with adjacent basal bodies and with the cell periphery via a dual set of fibre-containing flat trabeculae, both of which are attached to a special organizing centre, the basal foot cap. The distal trabecula is composed of microtubules and the proximal of microfilaments. Connecting the trabeculae, at vertices in the filamentous grids, are core bundles of microfilaments from apical microvilli. In this way, a zig-zag pattern that characterizes microvillar organization at the cell surface is generated. At the cell periphery, the microfilaments from basal foot caps join a peripheral band of microfilaments that underlies the cell border and is associated with four special sites, one in each corner of the cell. Mussel gill epithelial cells contain a polypeptide that resembles actin in its mobility in sodium dodecyl sulphate/10% (w/v) polyacrylamide gels and its affinity for DNase I. Decoration with heavy meromyosin demonstrates that many microfilaments of the L cell apex contain actin, including the microvillar core and peripheral band microfilaments. Actin-associated proteins are also present in these epithelial cells. The actin filaments of the peripheral band are organized to support contraction of the cell border, which would also affect each element of the cortex. This structural complexity, combined with the limited number of modes of interaction between various elements, suggests that the L cell apical cytoskeleton endows the cell with significant positional and morphogenetic information that could be used to compute organellar and cytoskeletal lengths, spacing and changes upon stimulation.

Dynein arm substructure and the orientation of arm-microtubule attachments

In the presence of AMP-PCP (beta, gamma-methyleneadenosine 5'-triphosphate), a non-hydrolyzable analog of ATP, negative stain images of increased morphological detail indicate that the dynein arm, attached to ciliary doublet microtubules, is composed of subunits including a cape, an elongated body and a head. The arrangement of these subunits makes it possible to distinguish A from B subfiber binding sites on a single arm and to demonstrate that the head of an extended arm on subfiber A of one ciliary doublet is capable of binding to subfiber B of an adjacent doublet in a specific orientation, which supports a key step in a current model of the mechanochemical cycle by which the arm produces microtubule sliding in the ciliary axoneme.

Optical purity determination and 1H NMR spectral simplification with lanthanide shift reagents — V. Mephenytoin, 5-ethyl-3-methyl-5-phenyl-2,4-imidazolidinedione

The 60-MHz 1H NMR spectra of racemic mephenytoin, I, have been studied with the achiral shift reagent, tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octane-dionato) europium (III), II, and the chiral reagent, tris[3-(trifluoromethylhydroxy-methylene)-d-camphorato] europium (III), III. Moderate values of the enantiomeric shift differences, Delta, were clearly observed for the NCH3, NH, aryl and CCH3 resonances in CDCl3 solution at 28 degrees C with added III. The NCH3 and NH absorptions could be useful for direct assays of optical purity. Thus, for a 0.34 molal solution of I in CDCl3 with a molar ratio III:I of 0.138, the value of Delta for the NCH3 resonance was 3.1 Hz (0.052 ppm) with 32% valley resolution.

The mechanochemical cycle of the dynein arm

A dynein arm attachment cycle produces sliding between adjacent doublet microtubules (N and N + 1) of cilia. In intact axonemes, in the absence of ATP, almost all arms appear attached at both ends (rigor). When ATP is added, most arms detach from doublet N + 1. In ATP and vanadate, the arms do not return to rigor, suggesting that ATP hydrolysis is required for re-extension and reattachment of the dynein arm, but not for detachment. Using solutions containing dynein to decorate dynein-less axonemal doublets, we confirm this interpretation. In the absence of ATP, both sides of each doublet decorate with arms. Addition of ATP, ATP and vanadate or AMP-PNP causes immediate arm detachment, but only in the first instance, where extensive ATP hydrolysis can occur, does decoration eventually reappear. Dynein decorates heterologous axonemal doublets and brain microtubules, as well as homologous doublets, suggesting that this mechanochemical cycle may have general applicability in microtubule-based cell motility.