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Retention strategies and participant retention rates among prospective longitudinal pregnancy cohorts: a systematic mapping review.

Prospective longitudinal pregnancy cohorts can answer questions about fetal and early life exposures and later health outcomes; however, there are challenges to retaining participants in longitudinal studies, particularly over life transitions like the birth of a child. Optimal methods for retaining participants in longitudinal research are unclear. A systematic mapping review was conducted to identify prospective cohort studies and randomized controlled trials that enrolled pregnant participants and their infants. Data on retention rates and 17 retention strategies was extracted. A random effects meta-analysis generated pooled annual retention rates inversely weighted to the number of baseline participants. Spearman rank coefficients were used to assess correlation between strategy use and retention. A random-effects meta-regression was used to determine if select retention strategies were associated with participant retention. We identified 130 studies, involving 472 022 pregnancies. A downward trend in pooled mean retention rates were observed. Studies utilized an average of 6.8 (SD 3.9) retention strategies. Statistically significant associations were not observed between strategy use and retention rates at follow-up (p > 0.05). Prospective studies of pregnant people and their infants used multiple retention strategies. Participant retention rates declined over time, suggesting that additional factors may influence study participation in the postpartum period.

Humans

Influence of endodontic access on the fracture resistance, retention and microleakage of full-coverage restorations in vitro: A systematic review and meta-analysis.

BACKGROUND: Endodontic access through retained full-coverage restorations (FCRs) is a preferred option for patients because of its high cost-effectiveness. However, the clinical performance of FCRs after repaired access cavity remains insufficiently characterized. This systematic review investigates the effects of endodontic access cavity preparation through retained FCRs on fracture resistance, retention, and microleakage based on in vitro studies. METHODS: A comprehensive search was performed in PubMed, Web of Science, and Scopus databases. Studies investigating the influence of endodontic access on the fracture resistance, retention, and microleakage of FCRs were included. Two independent reviewers conducted study selection, data extraction, and risk-of-bias assessment using the QUIN tool. Meta-analysis was employed to estimate fracture resistance and retention, with sensitivity analysis and subgroup evaluation also performed. Microleakage was summarized qualitatively. RESULTS: Twentythree studies were included: fracture resistance (n = 15), retention (n = 5), and microleakage (n = 3). Endodontic access significantly reduced fracture resistance for zirconia (p = 0.0002) and lithium disilicate (LD) restorations (p = 0.007), but not for resin-matrix ceramic (RMC) restorations (p = 0.25). Abutment tooth type contributed to heterogeneity within the LD and RMC subgroups. Retention was significantly reduced when access cavities were left unrepaired (p = 0.03), whereas appropriate repair protocols restored or enhanced retention relative to baseline. Accelerated aging increased microleakage in retained FCRs. Surface pretreatments and flowable resin liners tended to reduce microleakage, but findings were inconsistent. CONCLUSIONS: Endodontic access significantly reduces fracture resistance of zirconia and LD FCRs, whereas RMC restorations show no significant change. Appropriate repair protocols can restore or improve retention, potentially exceeding original values. Limited evidence suggests that effective sealing is achievable with appropriate materials. However, well-designed and in-vivo researches are needed to provide more detailed clinical guidance. CLINICAL SIGNIFICANCE: When performing endodontic access through retained FCRs, reduced fracture resistance must be carefully considered for zirconia and LD restorations, while RMC restorations may be exempt from this concern. Loss of retention with access can be restored after repair. Surface pretreatment and flowable resin liners help decrease microleakage.

Humans

Preregistration nursing student attrition and strategies to improve student retention in university; an umbrella review.

BACKGROUND: Attrition among preregistration nursing students remains a persistent international challenge, contributing to nursing workforce shortages. Although extensive research has examined factors influencing student attrition and retention, the evidence is fragmented across review-level literature, limiting clarity regarding priority and evidence-informed retention strategies. AIM: To synthesize review-level evidence on factors associated with preregistration nursing student attrition and to identify strategies that support student retention in university-based nursing programs. METHODS: An umbrella review was conducted in accordance with the Joanna Briggs Institute methodology. Six electronic databases were systematically searched for peer-reviewed literature reviews published in English between January 2016 and October 2025. Eligible reviews focused on undergraduate preregistration nursing students in face-to-face university programs. Methodological quality was appraised using the JBI critical appraisal checklist. Findings were synthesised using narrative and thematic approaches. RESULTS: Seventeen literature reviews were included. Attrition was consistently described as multifactorial, influenced by academic preparedness, psychosocial wellbeing, socio-demographic factors, and institutional support. Retention strategies reported across reviews were predominantly relational, developmental, and sustained over time, including mentoring, tutoring, academic skills development, psychosocial support, and interventions that foster belonging. Faculty engagement and holistic approaches were repeatedly associated with improved student persistence. However, the evidence base was largely descriptive, with limited experimental evaluation of intervention effectiveness. CONCLUSION: Preregistration nursing student retention is best supported through multifaceted, sustained strategies that begin at admission and extend throughout the curriculum. While current evidence highlights consistent patterns of effective support, further rigorous research is required to evaluate retention interventions and extend evidence to flexible nursing education pathways.

Humans

Elevated intron retention implicates neuroinflammation in brains of individuals with alcohol use disorder.

Intron retention, a form of alternative RNA splicing, can occur as part of normal gene regulation or result from disruption of the splicing machinery. Retained introns can potentially form double-stranded RNA, activating innate immune sensors and inflammation. This mechanism has been implicated in cancer but has not been studied in neuropsychiatric diseases like alcohol use disorder. We systematically analysed transcriptome-wide intron retention events in post-mortem brain tissue from 142 individuals (66 with alcohol use disorder and 76 controls), encompassing 320 region-specific samples from the superior frontal cortex, nucleus accumbens, central nucleus and basolateral amygdala. Analyses were adjusted for demographic, technical and biological covariates. Validation was performed in alcohol-preferring (P) rats using long-read sequencing. In complementary experiments, immunofluorescent staining was used to detect double-stranded RNA in rat brain tissue, while single-cell RNA-sequencing was performed to test activation of double-stranded RNA-sensing pathways in human brains. Brains from individuals with alcohol use disorder showed significantly higher total intron retention compared with controls, independent of age, with females showing greater increases than males. A total of 368 introns were positively associated with alcohol use disorder, and these introns were significantly longer and had weaker splice acceptor sites compared with non-associated introns. Genes harbouring these intron retention events were enriched in Purkinje neurons, visual cortex neurons and oligodendrocytes. Computational predictions indicated these long introns could form duplex RNA structures. Increased double-stranded RNA was confirmed experimentally in multiple brain regions of alcohol-consuming rats, where it co-localized primarily with neuronal nuclei and dendrites. In individuals with alcohol use disorder, we found that multiple pathways including double-stranded RNA responses, neuroinflammation, interferon and NF-κB signalling, adaptive immunity and apoptosis were activated. In addition, NeuN-positive neuronal counts significantly decreased in both the prefrontal and visual cortices. Furthermore, single-cell analysis demonstrated upregulation of TICAM1, the target of double-stranded RNA sensor TLR3, in oligodendrocytes, as well as widespread activation of downstream inflammatory pathways across glial and neuronal cell types. These findings provide the first evidence that chronic alcohol consumption promotes an overall increase of intron retention in the brain and is associated with the presence of double-stranded RNA. Furthermore, the double-stranded RNA may contribute to neuronal loss and brain pathology by activating a neuroinflammatory response.

alcohol use disorder

Migration intentions among nigerian neurosurgeons: a national survey of workforce retention.

Physician emigration from low- and middle-income countries creates critical workforce shortages. This study explored factors influencing migration intentions among Nigerian neurosurgeons and trainees. We conducted an anonymized survey of consultant neurosurgeons, fellows, and residents practicing in Nigeria. Invitations were sent by email and professional messaging platforms, and snowball sampling was used to increase participation. The survey included quantitative and open-ended questions on demographics, income, migration plans, and retention factors. Seventy-nine respondents participated (61.5 % consultants; 93.7 % male; median age: 44 years). Nearly all practiced general neurosurgery (97.3 %), and many also performed trauma (65.3 %) and spine (61.3 %) neurosurgery. Most (85.7 %) reported that their earnings were insufficient to support their families. Nearly 40 % were considering emigration, most often citing financial pressures (88.5 %) and poor working conditions (63.5 %) as push factors. By contrast, personal or family ties (63.0 %) and relocation costs (45.2 %) were cited as reasons to stay. Respondents identified higher salaries (58.1 %) and greater investment in the health sector (51.4 %) as key measures to improve retention. In univariable analyses, younger age, income insufficiency, income dissatisfaction, and feeling undervalued at work were associated with migration intention. Financial insecurity emerged as the dominant driver of migration intentions among Nigerian neurosurgeons. In addition to salary increases, sustained investment in healthcare infrastructure and workforce support is essential to improve retention. International partnerships may complement these efforts by building neurosurgical capacity and mitigating brain drain.

Humans

Retention of a single Cenp-C gene in different syntenic locations in the montium group of Drosophila species.

Chromosome segregation in eukaryotes requires the orchestrated interaction of chromosomes with microtubules, mediated by the kinetochore multiprotein complex that assembles on chromosomal regions known as centromeres. In most eukaryotes, CenH3 and Cenp-C centromeric proteins are essential for centromere function. In Drosophila, the localization of CenH3 (or Cid in Drosophila) depends on its chaperone CAL1 and Cenp-C. Previous studies have shown that both Cid and Cenp-C underwent a coincident gene duplication and likely functional specialization in the Drosophila subgenus. Independently, Cid duplications led to three paralogs in the montium group (Sophophora subgenus). Here, we investigated whether this group also underwent parallel Cenp-C duplications by analyzing sequenced genomes of 23 montium group species. We identified Cenp-C genes in five distinct syntenic loci. Despite their distinct synteny, all but two montium group species (except D. birchii and D. vulcana) encode a single Cenp-C, whose phylogeny mirrors the species phylogeny, and all encode protein motifs indicative of intact Cenp-C function. These Cenp-C genes resulted from gene translocations or duplication followed by loss of the ancestral copy. Therefore, the co-retention of three Cid paralogs in the montium group did not result in coincident Cenp-C paralog co-retention. Analysis of the selective constraints in Cenp-C reveals more prominent positive selection in the Drosophila subgenus (with two retained Cenp-C paralogs) than in the Sophophora subgenus, including the montium group. Our work highlights differences in functional retention and potential specialization of CenH3 and Cenp-C, two of the most conserved eukaryotic centromeric proteins in Drosophila.

Journal Article

The role of chromatin state in intron retention: A case study in leveraging large scale deep learning models.

Complex deep learning models trained on very large datasets have become key enabling tools for current research in natural language processing and computer vision. By providing pre-trained models that can be fine-tuned for specific applications, they enable researchers to create accurate models with minimal effort and computational resources. Large scale genomics deep learning models come in two flavors: the first are large language models of DNA sequences trained in a self-supervised fashion, similar to the corresponding natural language models; the second are supervised learning models that leverage large scale genomics datasets from ENCODE and other sources. We argue that these models are the equivalent of foundation models in natural language processing in their utility, as they encode within them chromatin state in its different aspects, providing useful representations that allow quick deployment of accurate models of gene regulation. We demonstrate this premise by leveraging the recently created Sei model to develop simple, interpretable models of intron retention, and demonstrate their advantage over models based on the DNA language model DNABERT-2. Our work also demonstrates the impact of chromatin state on the regulation of intron retention. Using representations learned by Sei, our model is able to discover the involvement of transcription factors and chromatin marks in regulating intron retention, providing better accuracy than a recently published custom model developed for this purpose.

Deep Learning

Primulina pan-genome reveals differential gene retention following whole-genome duplications and provides insights into edaphic specialization.

Primulina, a genus of >200 species specialized to extreme soils, provides a model for edaphic adaptation. We assemble seven genomes and construct a pan-genome spanning nine species from karst, Danxia, and acidic soils. Comparative analyses reveal that karst-adapted species have smaller genomes. Two lineage-specific whole-genome duplications (WGDs) exhibit biased duplicate loss in large gene families but preferential retention of transcription factors, indicating combined adaptive and nonadaptive forces. Pan-genome analyses identify ion channel and transporter genes enriched in variant hotspots and under positive selection in karst lineages. Candidate genes for drought and salt stress tolerance include ABC transporters and ion channels. Notably, an ABC transporter shows positive selection in karst species and unique structural variation in non-karst species. Together, our findings show that genome downsizing, biased post-WGD retention, and evolution of ion-transport pathways shape adaptation to extreme soils. The Primulina pan-genome provides a resource for dissecting mechanisms underlying edaphic specialization.

Gene Duplication

A needleless liquid jet injection delivery method for cardiac gene therapy: a comparative evaluation versus standard routes of delivery reveals enhanced therapeutic retention and cardiac specific gene expression.

This study evaluates needleless liquid jet method and compares it with three common experimental methods: (1) intramuscular injection (IM), (2) left ventricular intracavitary infusion (LVIC), and (3) LV intracavitary infusion with aortic and pulmonary occlusion (LVIC-OCCL). Two protocols were executed. First (n&#x2009;=&#x2009;24 rats), retention of dye was evaluated 10&#xa0;min after delivery in an acute model. The acute study revealed the following: significantly higher dye retention (expressed as % myocardial cross-section area) in the left ventricle in both the liquid jet [52&#x2009;&#xb1;&#x2009;4] % and LVIC-OCCL [58&#x2009;&#xb1;&#x2009;3] % groups p&#x2009;<&#x2009;0.05 compared with IM [31&#x2009;&#xb1;&#x2009;8] % and LVIC [35&#x2009;&#xb1;&#x2009;4] %. In the second (n&#x2009;=&#x2009;16 rats), each animal received adeno-associated virus encoding green fluorescent protein (AAV.EGFP) at a single dose with terminal 6-week endpoint. In the second phase with AAV.EGFP at 6&#xa0;weeks post-delivery, a similar trend was found with liquid jet [54&#x2009;&#xb1;&#x2009;5] % and LVIC-OCCL [60&#x2009;&#xb1;&#x2009;8] % featuring more LV expression as compared with IM [30&#x2009;&#xb1;&#x2009;9] % and LVIC [23&#x2009;&#xb1;&#x2009;9] %. The IM and LVIC-OCCL cross sections revealed myocardial fibrosis. With more detailed development in future model studies, needleless liquid jet delivery offers a promising strategy to improve direct myocardial delivery.

Animals

Engagement and Retention in Precision Public Health: A Cascade Analysis of Two Cluster Randomized Trials.

INTRODUCTION: When research fails to reach and engage all populations who might benefit from study findings, it can compromise scientific validity and ultimately health equity. Few studies have systematically examined factors driving study engagement through longitudinal intervention research. This project examined sociodemographic, geographic, and structural influences on engagement and attrition across the participation "cascade" (outreach, enrollment, retention) for two large-scale multilevel precision medicine and precision prevention trials for smoking and lung cancer screening. METHODS: Modified Poisson regression models were used to determine the factors associated with study engagement based on sociodemographic and geographical factors at each step in the cascade of participation, from initial outreach through retention at 12 months post-enrollment. Secondary analyses examined the cascade among the subset of patients who had active electronic patient portals and were approached via the portal. RESULTS: A total of 24,366 patients were approached for participation. Race, Social Vulnerability Index (SVI), insurance status, and distance from the study site were significantly associated with engagement at various points in the cascade. Black patients were more likely than White patients to be reached (48.9% vs 47.1%; p = 0.022) and to complete eligibility screening (52.8% vs. 38.4%; p < 0.001), but less likely to consent to participate (56.7% vs 69.8%; p < 0.001) and complete genetic testing (58.5% vs. 69.8%; p = 0.003). Patterns of engagement through electronic patient portal versus non-electronic recruitment channels also differed by race- and place-based factors, with Black patients being less likely than White patients to respond in the portal (8.8% vs 15.5%; p < 0.001), and patients who reside farther from the study site being more likely to respond in the portal compared to those who live closer (14.9% vs 12.5%; p < 0.001). CONCLUSIONS: These findings highlight the need for tailored, stage-specific engagement strategies to ensure representative participation in genomic and behavioral intervention research to advance the integration of genomics into public health practice.

Journal Article

The Germline SH2B3rs111340708 Splicing Variant Drives Intron Retention and Protein Instability by Impacting Clinical Outcomes in Core Binding Factor AML.

The SH2B3 gene, also known as LNK, encodes an adaptor protein that negatively regulates key hematopoietic signaling pathways, including JAK-STAT, MAPK, and PI3K/AKT, thereby maintaining hematopoietic homeostasis. SH2B3 interacts with major signaling regulators such as JAK2, MPL, FLT3, and KIT. Loss-of-function alterations have been reported in several hematologic malignancies, supporting its role as a leukemia predisposition gene. We previously identified a germline start-loss mutation (c.3G&#xa0;>&#xa0;A) in SH2B3 in a family with early-onset myeloproliferative neoplasm, demonstrating that this variant causes SH2B3 haploinsufficiency. In the present study, next-generation sequencing of 149 de novo AML patients identified a frequent intronic polymorphism (rs111340708), located within intron 6 (IVS6) of SH2B3. Although this variant has a reported minor allele frequency (MAF) of approximately 12% in European populations, it was enriched in our AML cohort, reaching 34.2% in Core Binding Factor leukemias (CBFLs). The presence of the rs111340708 variant was associated with inferior overall survival, whereas no significant association with progression-free survival was observed. Functional analyses demonstrated that this polymorphism promotes aberrant IVS6 intron retention in AML cells, resulting in reduced abundance of correctly spliced SH2B3 transcripts and predicted generation of truncated peptides and/or nonsense-mediated decay. Consistently, immunoblot analyses of AML patient samples and hematologic cell lines revealed heterogeneous SH2B3 protein expression, including additional SH2B3-immunoreactive species in variant carriers, together with reduced levels of the canonical SH2B3 protein. Collectively, these findings identify a common germline splicing polymorphism as a novel mechanism contributing to SH2B3 functional impairment in AML and highlight the potential relevance of non-coding variants in leukemia pathogenesis, with possible implications for risk stratification and future therapeutic strategies.

Humans

Weight Loss without Food Intake Suppression through Size-Dependent Retention of Anti-Inflammatory Nanomedicines.

Obesity is a risk factor for high-mortality health conditions, including cardiovascular diseases and type 2 diabetes, which makes the advancement of efficacious and safe weight loss therapies a high priority in pharmacology. The causal link between obesity and its comorbid conditions is believed to be a chronic state of inflammation originating within adipose tissue, with macrophages playing central roles, an axis that is not targeted directly by current therapies. Here, we use nanocarriers to deliver an anti-inflammatory glucocorticoid receptor agonist to adipose tissue macrophages and report the impact of size on therapeutic effect. Three dextran nanocarriers between 4-30 nm in hydrodynamic diameter released molecular drug cargo at equivalent rates and exhibited similar biological potency in vitro. In vivo in a mouse model of obesity, body weight and body fat were reduced in a size-dependent manner after 2-4 weeks of treatment. Unlike current clinical pharmacotherapies for weight loss, these body composition changes were not associated with changes in food intake. Greater retention of larger dextran nanocarriers in visceral adipose tissue appears to elicit a local change to promote browning by increasing mitochondrial abundance and lipid droplet fragmentation. Further development of this platform may result in a safe and potent modulator of adipose tissue in the state of obesity without direct action on nutrient intake to address malnutrition and lean body mass deficiencies observed with current weight loss pharmacotherapies.

Animals

PRMT5-mediated intron retention triggers innate and adaptive immunity against cancer.

PRMT5 is expressed at high levels in many cancers, where it regulates diverse cellular pathways that contribute to oncogenesis. Here, we have defined a new role for PRMT5 in regulating and coordinating the interplay between the innate and adaptive immune response. This occurs, in part, through the influence of PRMT5 and E2F1 on RNA splicing and the presence of retained introns (RIs). We found that RIs have a propensity to form double-stranded RNAs that contribute to the innate response. Furthermore, many RIs contain non-canonical open-reading frames (ncORFs), which can be translated and then processed into small peptides that assemble with the MHC class I complex. Significantly, RI-derived peptides are highly immunogenic and, as a murine cancer vaccine, carrying a string of antigenic RI peptides, delayed tumour growth and enhanced survival. RIs are present in human tumour cells, and we identified T lymphocytes in human cancer patients, with antigen specificity for RI-derived peptides, that killed human tumour cells in vitro. Regulating intron retention thus offers a new therapeutic approach to enhance tumour immunogenicity.

Animals

Ten years on, still out of reach: barriers to PrEP access and retention in France according to frontline actors (QualiPrEP Study).

Pre-exposure prophylaxis (PrEP) for HIV has been available in France since 2014, and reimbursed since 2016, with general practitioners allowed to prescribe it since 2021. Despite these policy advances, uptake remains low among some of the most affected populations. This community-based qualitative study explored barriers to PrEP access and retention ten years into its implementation.Interviews were conducted with 28 PrEP frontline actors (healthcare professionals and community-based workers involved in promoting, prescribing, or supporting PrEP). The sample included one group discussion (n = 5), two triads (n = 6), two dyads (n = 4), and nine individual interviews (n = 13). Thematic analysis was inductive, with barriers classified across four main domains.Participants were mostly cisgender men, median age 48, born in France and abroad, and employed by NGOs in Paris. Thirteen barriers and four major themes emerged: (1) Internal psychosocial barriers: lack of knowledge, negative health-related reactions; HIV stigma; STI risk perception, taboos; (2) Internal pragmatic barriers: perceived limits of protection, usage and follow-up constraints; (3) External psychosocial barriers: limited physician knowledge and reluctance; (4) External pragmatic barriers: communication failures; structural constraints, lack of human and financial resources.Findings call for more targeted messaging, simplified care models and provider training. They highlight the need to address social and symbolic dimensions of PrEP, with insights from those supporting users to ensure more equitable implementation.

Humans

Angiotensin signaling is essential for stress erythropoiesis but causes retention of dysfunctional mitochondria in RBCs.

We previously reported that excessive angiotensin-II&#x2192;AT receptor-1 (AT&#x2192;ATR1) signaling results in sickle cell anemia-associated (SCA-associated) nephropathy. Herein, we showed that hyperangiotensinemia in SCA results from high erythroid cell-generated reactive oxygen species (ROS), which oxidized angiotensinogen (ATGN) and favored its rapid conversion to AT. Increased AT&#x2192;ATR1 signaling in SCA erythroid cells generated ROS and created a positive feedback loop of ROS&#x2192;oxidized ATGN&#x2192;AT&#x2192;ATR1&#x2192;ROS, perpetuating the hyperangiotensinemia. ATR1 blocker, losartan, reduced erythrocyte ROS, oxidized ATGN, and AT levels. The ROS&#x2192;AT&#x2192;ATR1&#x2192;ROS loop was driven by sickle erythropoiesis, as it was reproduced when WT mice were transplanted with SCA hematopoiesis. Using SCA and WT mice with germline- and erythroid-specific ATR1 deficiency, we found that stress erythropoiesis, but not steady-state erythropoiesis, was critically dependent on erythroid AT&#x2192;ATR1 signaling, which acted in harmony with increased erythropoietin signaling. Furthermore, instead of the canonical AT&#x2192;ATR1&#x2192;NADPH-oxidase&#x2192;ROS signaling in steady-state erythropoiesis, AT&#x2192;ATR1 signaling in stress erythroid cells increased mitochondrial mass and dysfunctional mitochondria, which thereby increased ROS. SCA mice with erythroid-specific ATR1 deficiency had decreased RBC accumulation of dysfunctional mitochondria and decreased ROS, which reduced SCA-associated nephropathy. Overall, we demonstrate that AT&#x2192;ATR1 signaling was essential for stress erythropoiesis but led to increased dysfunctional mitochondria retention in mature RBCs, which generated ROS and perpetuated hyperangiotensinemia, resulting in end-organ damage.

Animals

Retention and Rearrangement of Membrane Protein Complexes' Higher Order Structure by Collisionally Activated Dissociation- and Electron Capture Dissociation-Mass Spectrometry.

Membrane proteins (MPs) challenge biophysical and structural biology methods. Native mass spectrometry (MS) has emerged as a powerful tool to study MP structures and their modulation by lipids. We examine the pathways by which three MPs, tetrameric Aquaporin Z (AqpZ), trimeric ammonium transporter (AmtB), and pentameric mechanosensitive channel of large conductance (MscL) decompose following collisionally activated dissociation (CAD) or electron capture dissociation (ECD) in native top-down MS. MPs subjected to CAD typically decompose along well-characterized pathways releasing highly charged monomers and low-charge state complementary subunits, but a lesser pathway accessed by low pressure collisions cleaves the backbone into fragments covering much of the sequence. Collisions also rearrange structures, e.g., AmtB subunits rearrange to form novel interactions and/or salt bridges that surprisingly retain a formerly surface-exposed segment despite ejecting the binding interface. MscL dissociation pathways depend on precursor charge-state, a behavior observed in a few soluble complexes, yet unaddressed mechanistically. Salt bridges in low charge state complexes stabilize subunits from ejection while facilitating only smaller, local rearrangements that release covalently cleaved products from transmembrane regions. With fewer opposite charges, on average, higher charge state molecules can rearrange intersubunit salt bridges on the experimental time scale to partition charge asymmetrically and free a subunit. ECD with supplemental activation can retain higher order structures of proteins and inform about the strongly interacting regions that preclude product ion release. With extensive regions lacking ionizable residues, MPs enable key interactions that guide the structure and dynamics of gas phase protein assemblies to be probed.

Mass Spectrometry

Rab9 depletion enhances human adenovirus type 26 transduction efficiency through increased internalization and reduced late endosomal/lysosomal retention.

Understanding intracellular trafficking is central to decoding viral pathogenesis and engineering optimized viral vectors. How a virus or vector is routed through the endocytic pathway directly dictates its genome release, immune sensing, and overall transduction efficiency. Human adenovirus type 26 (HAdV-D26) presents a promising platform for vector design due to its low preexisting immunity, potent immune stimulation, scalable production, and versatile genetic engineering capacity. Although increasingly significant, the fundamental mechanisms governing HAdV-D26 intracellular trafficking are still not fully understood. Our study demonstrates that compared to well-described human adenovirus type 5 (HAdV-C5), HAdV-D26 undergoes prolonged intracellular trafficking, transiently localizing to early endosomes before residing in late endosomes/lysosomes for up to four hours post-infection. Inhibition of lysosomal acidification modestly enhances HAdV-D26 transduction efficiency, whereas blocking transport from early to late endosomes/lysosomes does not. Strikingly, Rab9 knockdown reduces HAdV-D26 late endosomal/lysosomal localization while increasing both virus internalization and genome delivery to the host cell nucleus. These findings indicate that late endosomal sorting pathways actively influence HAdV-D26 infection outcomes. By identifying a previously unappreciated role for Rab9 in adenovirus transduction, our results provide new mechanistic insight into HAdV-D26 intracellular trafficking, highlight serotype-specific differences in adenovirus entry pathways, and identify endosomal trafficking steps that may be targeted to improve adenoviral vector performance.

Humans

Clinical performance of a giomer-based pit and fissure sealant with and without air-abrasion pretreatment: a 12-month randomized clinical trial.

BACKGROUND: Pit and fissure sealants are widely used for caries prevention; however, their long-term success depends largely on retention. Giomer-based sealants containing surface pre-reacted glass ionomer fillers offer bioactive properties, yet concerns remain regarding their bonding durability when applied with mild self-etch primers. This randomized clinical trial evaluated the effect of bioactive glass air-abrasion pretreatment on the retention and caries preventive efficacy of a giomer-based sealant in young adults over 12 months. METHODS: This parallel-arm randomized clinical trial included 96 participants, each contributing one eligible sound permanent molar (n&#x2009;=&#x2009;48 per group). Participants were randomly allocated to either bioactive glass air-abrasion pretreatment followed by application of a giomer-based sealant (intervention group) or application of the same sealant without pretreatment (comparator group). Sealant retention and secondary caries incidence were evaluated at baseline, 6 months, and 12 months using Simonsen's criteria, and modified United States Public Health Service (USPHS) criteria, respectively. The primary outcome was sealant retention at 12 months, whereas secondary caries incidence was assessed as a secondary outcome. Intergroup comparisons were analyzed using the Chi-square test. Intragroup comparisons were analyzed using Cochran's Q test followed by multiple comparisons. Relative risk with 95% confidence intervals was calculated. Statistical significance was set at p&#x2009;&#x2264;&#x2009;0.05. RESULTS: At 6 months, complete sealant retention was observed in 91.7% of teeth in the intervention group and 75.0% in the comparator group, with no statistically significant difference between groups (p&#x2009;=&#x2009;0.068). At 12 months, complete sealant retention was significantly higher in the intervention group (87.5%) than in the comparator group (33.3%) (p&#x2009;<&#x2009;0.0001). Teeth in the intervention group exhibited an 81.25% lower risk of sealant retention failure compared with the comparator group (RR&#x2009;=&#x2009;0.1875; 95% CI: 0.0864-0.4069; p&#x2009;<&#x2009;0.0001). No differences in secondary caries incidence were detected between groups during the 12-month follow-up period (p&#x2009;=&#x2009;1.0000). CONCLUSIONS: Bioactive glass air-abrasion pretreatment significantly improved the retention of a giomer-based fissure sealant compared with sealant application without pretreatment. No differences in secondary caries incidence were detected between groups during the 12-month follow-up period. Incorporating mechanical surface conditioning prior to sealant placement may enhance sealant retention without compromising preventive efficacy. TRIAL REGISTRATION: https://clinicaltrials.gov/ , (NCT06003452), 15-08-2023.

Humans