A Scoping Review of Oral Pre-exposure Prophylaxis for Cisgender and Transgender Adolescent Girls and Young Women: What Works and Where Do We Go from Here?

Adolescent girls and young women (AGYW) are disproportionately affected by HIV, and oral pre-exposure prophylaxis (PrEP) can reduce HIV acquisition. The purpose of this scoping review was to synthesize results from interventions along the PrEP continuum for AGYW to inform research and programs. We searched electronic databases for studies published between January 2012-July 2021 and conducted secondary reference searching. Studies were included if they assessed interventions to increase PrEP interest, uptake, or continuation among AGYW. Results were synthesized narratively. Of 2168 citations identified, 50 studies were eligible for inclusion, and 20 contained AGYW-specific data. Among cisgender and transgender AGYW, studies overall demonstrated a positive impact on PrEP interest and uptake but generally attained suboptimal continuation rates. Results demonstrate feasibility of deploying PrEP across diverse settings-particularly when interventions are layered, tailored to AGYW, and include differentiated delivery-but also highlight knowledge gaps and the need for more holistic metrics of success.

RESUMEN: Las adolescentes y las mujeres jóvenes se ven afectadas de forma desproporcionada por el VIH, y la Profilaxis Pre-Exposición oral (PrEP) puede reducir la adquisición del VIH. El propósito de esta revisión de alcance fue sintetizar los resultados de las intervenciones a lo largo del continuo de la PrEP para las adolescentes y las mujeres jóvenes con el fin de informar la investigación y los programas. Se realizaron búsquedas en bases de datos electrónicas de estudios publicados entre enero 2012 a julio 2021 y se llevó a cabo una búsqueda secundaria de referencias. Los estudios se incluyeron si evaluaban intervenciones para aumentar el interés, la iniciación, o la continuación de la PrEP entre las adolescentes y las mujeres jóvenes. Los resultados se sintetizaron narrativamente. De las 2168 citas identificadas, 50 estudios fueron elegibles para inclusión y 20 contenían datos específicos de las adolescentes y las mujeres jóvenes. Entre las adolescentes y las mujeres jóvenes cisgénero y transgénero, los estudios demostraron un impacto positivo en el interés y la iniciación de la PrEP, pero en general alcanzaron tasas de continuación subóptimas. Los resultados demuestran la viabilidad del despliegue de la PrEP en diversos entornos­en particular cuando las intervenciones son estratificadas, se adaptan a las adolescentes y las mujeres jóvenes, e incluyen una prestación diferenciada­pero también destacan las lagunas de conocimiento y la necesidad de una métrica más holística del éxito.

Family planning provision in pharmacies and drug shops: an urgent prescription.

Drug shops and pharmacies have long been recognized as the first point of contact for health care in developing countries, including family planning (FP) services. Drug shop operators and pharmacists should not be viewed as mere merchants of short-acting contraceptive methods, as this ignores their capacity for increasing uptake of FP services and methods in a systematic and collaborative way with the public sector, social marketing groups and product distributors. We draw on lessons learned from the rich experience of earlier efforts to promote a variety of public health interventions in pharmacies and drug shops. To integrate this setting that provides convenience, confidentiality, access to user-controlled contraceptive methods (i.e., pills, condoms and potentially Sayana Press®) and a gateway to clinic-based FP services, we propose three promising practices that should be encouraged in future interventions to increase access to quality FP services.

Injectable contraceptive sales at licensed chemical seller shops in ghana: access and reported use in rural and periurban communities.

CONTEXT: Most women in Ghana obtain oral contraceptives and condoms from shops run by licensed chemical sellers, but such shops are not legally permitted to sell the country's most widely used method, the injectable. Allowing shops to sell the injectable could increase access to and use of the method. METHODS: In 2012-2013, semistructured telephone interviews were conducted among convenience samples of 94 licensed chemical seller shop operators in two districts who were trained to sell the injectable and of 298 women who purchased the method from these shops. Follow-up interviews were conducted with 92 clients approximately three months after their initial injectable purchase. RESULTS: Ninety-seven percent of shop operators reported selling the injectable, and 94% felt sufficiently trained to provide family planning methods and services. Virtually all sellers (99%) referred clients to a hospital or health facility for injection; none provided injections themselves. Fifty-six percent of injectable clients were new family planning users. Of those who completed a follow-up interview, 79% had purchased the injectable again from a shop. Virtually all clients (97%) reported getting their injection at the health facility to which they were referred by the seller. Women cited trust, convenience and commodities being in stock as key reasons for purchasing from a shop. CONCLUSION: Licensed chemical seller shop operators can safely sell the injectable and refer clients to health facilities for screening, counseling and injection.

Auxin-responsive DR5 promoter coupled with transport assays suggest separate but linked routes of auxin transport during woody stem development in Populus.

Polar auxin transport (PAT) is a major determinant of plant morphology and internal anatomy with important roles in vascular patterning, tropic growth responses, apical dominance and phyllotactic arrangement. Woody plants present a highly complex system of vascular development in which isolated bundles of xylem and phloem gradually unite to form concentric rings of conductive tissue. We generated several transgenic lines of hybrid poplar (Populus tremula x alba) with the auxin-responsive DR5 promoter driving GUS expression in order to visualize an auxin response during the establishment of secondary growth. Distinct GUS expression in the cambial zone and developing xylem-side derivatives supports the current view of this tissue as a major stream of basipetal PAT. However, we also found novel sites of GUS expression in the primary xylem parenchyma lining the outer perimeter of the pith. Strands of primary xylem parenchyma depart the stem as a leaf trace, and showed GUS expression as long as the leaves to which they were connected remained attached (i.e., until just prior to leaf abscission). Tissue composed of primary xylem parenchyma strands contained measurable levels of free indole-3-acetic acid (IAA) and showed basipetal transport of radiolabeled auxin ((3)H-IAA) that was both significantly faster than diffusion and highly sensitive to the PAT inhibitor NPA. Radiolabeled auxin was also able to move between the primary xylem parenchyma in the interior of the stem and the basipetal stream in the cambial zone, an exchange that was likely mediated by ray parenchyma cells. Our results suggest that (a) channeling of leaf-derived IAA first delineates isolated strands of pre-procambial tissue but then later shifts to include basipetal transport through the rapidly expanding xylem elements, and (b) the transition from primary to secondary vascular development is gradual, with an auxin response preceding the appearance of a unified and radially-organized vascular cambium.

Diversification and Expression of the PIN, AUX/LAX, and ABCB Families of Putative Auxin Transporters in Populus.

Intercellular transport of the plant hormone auxin is mediated by three families of membrane-bound protein carriers, with the PIN and ABCB families coding primarily for efflux proteins and the AUX/LAX family coding for influx proteins. In the last decade our understanding of gene and protein function for these transporters in Arabidopsis has expanded rapidly but very little is known about their role in woody plant development. Here we present a comprehensive account of all three families in the model woody species Populus, including chromosome distribution, protein structure, quantitative gene expression, and evolutionary relationships. The PIN and AUX/LAX gene families in Populus comprise 16 and 8 members respectively and show evidence for the retention of paralogs following a relatively recent whole genome duplication. There is also differential expression across tissues within many gene pairs. The ABCB family is previously undescribed in Populus and includes 20 members, showing a much deeper evolutionary history, including both tandem and whole genome duplication as well as probable gene loss. A striking number of these transporters are expressed in developing Populus stems and we suggest that evolutionary and structural relationships with known auxin transporters in Arabidopsis can point toward candidate genes for further study in Populus. This is especially important for the ABCBs, which is a large family and includes members in Arabidopsis that are able to transport other substrates in addition to auxin. Protein modeling, sequence alignment and expression data all point to ABCB1.1 as a likely auxin transport protein in Populus. Given that basipetal auxin flow through the cambial zone shapes the development of woody stems, it is important that we identify the full complement of genes involved in this process. This work should lay the foundation for studies targeting specific proteins for functional characterization and in situ localization.

Kinematic response of lumbar functional spinal units to axial torsion with and without superimposed compression and flexion/extension.

Experimental data suggest that lumbar torsion contributes to lumbar disc degenerative changes, such as instability, spondylolisthesis and spinal canal stenosis. However, some basic mechanical characteristics of the lumbar spine under torsional loading have not yet been reported in detail. For example, the function of the facet joints under combined mechanical loads such as torsion with superimposed flexion or extension postures is an area of interest about which little biomechanical data have been reported. In this study, the kinematic response to axial torsion with superimposed axial compression (200 N), compression-flexion (3 and 6 Nm) and compression-extension (3 and 6 Nm) was investigated in 10 cadaveric lumbar functional spinal units. Range of motion (ROM), and helical axes of motion (HAM), were analyzed. There was no difference in ROM between no preload, pure compressive and flexion-compression preload conditions. The ROM was significantly reduced by both extension-compression preload conditions (11% reduction for 3 Nm and 19% reduction for 6 Nm of extension) compared to the pure compressive preload. For no preload, the average HAM position in the transverse plane of the intervertebral disc was near the posteriormost part of the disc and located laterally on the side contralateral to the applied torsional moment. In the transverse plane, the HAM position showed a discrete trend towards the posterior part of the specimens during extension. Kinematic data were visualized using computer animation techniques and CT-based reconstructions of the respective specimens. This information may be used for identifying and characterizing physiologic and pathologic motion and for specifying conservative and surgical treatment concepts and, thus, may find application to identifying indications for spinal fusion or in evaluating the effect of future semi-flexible instrumentation.

Factors influencing stresses in the lumbar spine after the insertion of intervertebral cages: finite element analysis.

Intervertebral cages in the lumbar spine have been an advancement in spinal fusion to relieve low back pain. Even though initial stability is accepted as a requirement for fusion, there are other factors. The load transfer and its effect on the tissues adjacent to the cage may also play an essential role, which is not easily detectable with experimental tests. In this study the effects of an intervertebral cage insertion on a lumbar functional spinal unit were investigated using finite element analyses. The influences of cage material, cancellous bone density and spinal loading for the stresses in a functional spinal unit were evaluated. Three-dimensional (3D) finite element models of L2-L3 were developed for this purpose. An anterior approach for a monobloc, box-shaped cage was modelled. Models with cage were compared to the corresponding intact ones. The results showed that inserting a cage increased the maximum von Mises stress and changed the load transfer in the adjacent structures. Varying the cage material or the loading conditions had a much smaller influence than varying the cancellous bone density. The denser the cancellous bone, the more the stress was concentrated underneath the cage, while the remaining regions were unloaded. This study showed that the density of the underlying cancellous bone is a more important factor for the biomechanical behaviour of a motion segment stabilized with a cage, and its eventual clinical success, than the cage material or the applied load. Inserting an intervertebral cage markedly changed the load transfer. The altered stress distribution may trigger bone remodelling and explain damage of the underlying vertebrae.

Posterior thoracic extrapedicular fixation: a biomechanical study.

STUDY DESIGN: In vitro biomechanical testing of thoracic spine specimens using a standardized three-dimensional spine flexibility protocol. OBJECTIVES: To compare the mechanical stability of the intrapedicular and extrapedicular technique for pedicle screw placement. The hypothesis was that extrapedicular screw placement provides an equally rigid construct. SUMMARY OF BACKGROUND DATA: Pedicle screws provide rigid fixation of instabilities in the lumbar and lumbosacral spine. Anatomic considerations and the potential risk of neurologic complications are the main reasons to hesitate using pedicle screws in the thoracic spine. Extrapedicular fixation would allow safer insertion due to an increased distance to the spinal canal. METHODS: Twelve human cadaveric thoracic spines (six intra-, six extrapedicular) were instrumented with the USS system, using computed tomography-based computer navigation to ensure accurate placement. The specimens were tested in flexion-extension, torsion, and lateral bending. The ROM was measured using an optoelectronic system, and the two methods were compared before and after implantation of the USS construct and before and after fatigue testing of the construct. RESULTS: The ROM of the instrumented spine was reduced to less than 50% that of its original ROM. There were no statistically significant differences in the ROM reduction between the intra- and the extrapedicular technique. Cyclic fatiguing of the construct did not significantly increase the ROM. CONCLUSIONS: The extrapedicular technique provides a construct for stabilization of the thoracic spine that is as rigid as the conventional intrapedicular technique, but has the advantage of a safer surgical screw insertion.

The importance of the endplate for interbody cages in the lumbar spine.

Intervertebral cages in the lumbar spine represent an advancement in spinal fusion to relieve low back pain. Different implant designs require different endplate preparations, but the question of to what extent preservation of the bony endplate might be necessary remains unanswered. In this study the effects of endplate properties and their distribution on stresses in a lumbar functional spinal unit were investigated using finite-element analyses. Three-dimensional finite-element models of L2-L3 with and without a cage were used. An anterior approach for a monobloc, box-shaped cage was modelled. The results showed that inserting a cage increased the maximum von Mises stress and changed the load distribution in the adjacent structures. A harder endplate led to increased concentration of the stress peaks and high stresses were propagated further into the vertebral body, into areas that would usually not experience such stresses. This may cause structural changes and provide an explanation for the damage occurring to the underlying bone, as well as for the subsequent subsidence of the cage. Stress distributions were similar for the two endplate preparation techniques of complete endplate preservation and partial endplate removal from the centre. It can be concluded that cages should be designed such that they rely on the strong peripheral part of the endplate for support and offer a large volume for the graft. Furthermore, the adjacent vertebrae should be assessed to ensure that they show sufficient density in the peripheral regions to tolerate the altered load transfer following cage insertion until an adequate adaptation to the new loading situation is produced by the remodelling process.