Distinct Developmental Patterns Research Articles

Differential Effects of Prenatal Buprenorphine and Methadone on Postnatal Growth and Gene Expression in the Nucleus Accumbens.

Methadone and buprenorphine are commonly prescribed during pregnancy to maintain recovery and prevent symptoms of withdrawal in women with opioid use disorder. Infants prenatally exposed to medications for opioid use disorder (MOUD), however, commonly show signs of neonatal opioid withdrawal syndrome (NOWS), which can include feeding-related issues like hyperphagia. To investigate the effects of prenatal MOUD exposure on feeding behavior, female Sprague-Dawley rats were implanted with osmotic minipumps filled with methadone, buprenorphine, or saline and subsequently mated. On postnatal day (PND) 1, buprenorphine- and methadone-exposed offspring weighed less than saline-exposed subjects. Throughout early postnatal development (PND2, 7, and 12), this reduction in weight persisted in buprenorphine, but not methadone, offspring. RNAscope in situ hybridization was then used to measure expression of genes in the nucleus accumbens (NAc) previously associated with hyperphagia in NOWS infants, including proopiomelanocortin (Pomc), neuropeptide Y2 receptors (Npy2r), and dopamine type 2 receptors (Drd2). Distinct developmental expression patterns were noted across the postnatal period, with few effects of MOUD; however, significantly lower Pomc expression was observed in methadone-exposed but not buprenorphine-exposed offspring. These findings demonstrate differential effects of methadone and buprenorphine on offspring development and gene expression, highlighting differences in offspring outcomes associated with these two MOUDs.

In vitro Evaluation of Antifungal Activity of Terbinafine Nano Form against Yeast Organism Isolated in Thumby Labs Ajman

The goal of this study is to evaluate the antifungal activity of terbinafine in its nano form against yeast organisms in vitro and compare its effectiveness to the normal form of terbinafine. Thirty isolated yeast organisms from Thumbay Labs were included in the study. Terbinafine was serially diluted to concentrations of 50 mg, 25 mg, 12 mg, and 6 mg for both the nano and normal forms. After preparing the serial dilutions, fungal suspensions were exposed to these dilutions for 7 minutes. The suspensions were then cultured on Sabouraud dextrose agar and incubated at 37°C overnight. Growth was measured using a colony count. The results for the normal form of terbinafine revealed growth at all concentrations, with varying colony counts with a highest growth was observed at the 6 mg concentration. In contrast, the nano form of terbinafine exhibited distinct development patterns. At the 50 mg concentration, seven samples showed no growth; at the 25 mg concentration, two samples showed no growth; and the remaining samples exhibited limited growth compared to the normal form. According to the results of this study, there were significant differences in the number of colonies between the two forms of terbinafine, with the nano form demonstrating greater efficacy. The most potent antifungal response was observed at the 50 mg concentration of nano terbinafine, which inhibited yeast growth in several samples. In conclusion, terbinafine nanoemulsions are more effective than the normal form against Candida.

Trajectories of depressive symptoms in early to mid-adolescence: associations with school pedagogical and social climate.

Adolescence is a critical period for mental health development, yet research exploring how contextual factors influence the development of depressive symptoms remains limited. This study explored trajectories of depressive symptoms during early to mid-adolescence and their association with various aspects of school climate. The study sample comprised 3671, 7th-grade students (aged 12-13 years) from 101 schools across Sweden, followed longitudinally across three time points spanning grades 7, 8 and 9. Depressive symptom trajectories were identified using latent class growth modelling. The Pedagogical and Social Climate questionnaire assessed school climate, and multinomial logistic regression was employed to predict trajectory membership based on sociodemographic and school climate factors. Four distinct developmental patterns of depressive symptoms emerged: 'Sustained low symptoms' (76.7%), 'Low-increasing' (10.9%), 'Sustained high symptoms' (7.9%), and 'High-decreasing' (4.5%). Gender, parental education and six specific school climate factors, out of the total 19 examined, significantly distinguished these trajectory classes. Positive teacher expectations and strong principal involvement were associated with more favourable trajectories, whereas teaching activities, teacher support and communication between school and home were associated with less favourable trajectories, suggesting a nuanced understanding of their relationship with depressive symptom trajectories. Few school factors were found to be relevant to depressive symptoms, highlighting the importance of considering external factors beyond the school environment in supporting adolescents during this developmental stage. Although the findings are multifaceted, it is primarily positive interpersonal relationships, especially through teacher expectations, that stand out as significant factors in promoting youth mental health.

Developmental trends in corpus callosum thickness among preschool children

BackgroundThe corpus callosum plays a crucial role in integrated brain functions, and its development in childhood is strongly associated with subsequent cognitive, emotional, and behavioral development. However, there is still a lack of clear understanding regarding the developmental trends of the corpus callosum in preschool children. This study aims to comprehensively investigate age and sex differences in the thickness of the corpus callosum in typical developing children between 1 and 6 years old. MethodsT1-weighted structural MRI data were collected from a sample of 295 neurologically normal children aged 1–6 years. Utilizing the specialized corpus callosum segmentation software Yuki, thickness measurements of the mid-sagittal plane of the corpus callosum were obtained. ResultsThe anterior part exhibited faster growth compared to the middle and posterior sections, while growth at the extremities was not statistically significant. Furthermore, gender differences were identified, with males showing earlier development of the corpus callosum, particularly between ages 1 and 3. Conversely, females exhibited the most notable increase in thickness between ages 3 and 5. ConclusionThis study provides significant insights into the developmental trends of the mid-sagittal plane of the corpus callosum in preschool children. It reveals distinct non-linear developmental patterns in different sections of the corpus callosum and highlights the influence of sex on these developmental patterns.

Transcriptomic analysis reveals differential gene expression patterns during cannabis leaf morphogenesis and phase transition

ABSTRACT Understanding the molecular mechanisms governing leaf morphogenesis and phase transition in Cannabis sativa is critical for optimizing its growth, development and yield. In this study, we conducted a comparative transcriptomic analysis to investigate the gene expression patterns associated with leaf development and the transition from vegetative to reproductive phases in cannabis plants. Following germination, cannabis plants display a distinct leaf developmental pattern. While the specific number of leaflets varies among cultivars, here we focused on the White Widow cultivar as a model. It showed an increase in the number of serrated leaflets from one (L1) to nine (L5) in a node-specific manner. Subsequently, the number of leaflets decreased from eight (L6) to three (L9). The transition from vegetative to reproductive phases, marked by the appearance of solitary flowers and a shift from opposite to alternate leaf phyllotaxy, occurred at node 7 and node 12, respectively. Analysis of gene expression revealed 1358 differentially expressed genes, with 1,182 genes showing differential expression across all leaves. Notably, several genes involved in leaf morphogenesis (e.g. YAB, AGO5, and TCP4) were found to be upregulated in compound leaves (L2) compared to simple leaves (L1), implying a role in leaflet formation and overall leaf morphology. Furthermore, several genes associated with phase transition and flowering (e.g. SPLs, ELFs, SOC1, and CEN-Like) exhibited specific expression patterns during the transition from vegetative to reproductive phases. These findings provide valuable insights into the genetic regulation of leaf morphogenesis and phase transition in cannabis.

Single cell dual-omic atlas of the human developing retina

The development of the retina is under tight temporal and spatial control. To gain insights into the molecular basis of this process, we generate a single-nuclei dual-omic atlas of the human developing retina with approximately 220,000 nuclei from 14 human embryos and fetuses aged between 8 and 23-weeks post-conception with matched macular and peripheral tissues. This atlas captures all major cell classes in the retina, along with a large proportion of progenitors and cell-type-specific precursors. Cell trajectory analysis reveals a transition from continuous progression in early progenitors to a hierarchical development during the later stages of cell type specification. Both known and unrecorded candidate transcription factors, along with gene regulatory networks that drive the transitions of various cell fates, are identified. Comparisons between the macular and peripheral retinae indicate a largely consistent yet distinct developmental pattern. This atlas offers unparalleled resolution into the transcriptional and chromatin accessibility landscapes during development, providing an invaluable resource for deeper insights into retinal development and associated diseases.

Association between developmental patterns of single and concurrent externalizing behaviors and internalizing problems over the preschool years.

The present study investigated whether distinct developmental patterns of externalizing behaviors (EBs: hyperactivity-impulsivity, noncompliance, physical aggression) based on parent reports were repeatedly and differentially associated with separate dimensions of internalizing problems such as general anxiety, separation anxiety, and depressive symptoms across the early, middle, and late preschool years in a population birth cohort (N = 2,057, 50.7% boys). Six high trajectory classes obtained by latent growth modeling were used as longitudinal indicators of single EB and co-occurrent EBs. Children following low or moderate trajectories for all EBs served as the reference class. Results revealed that children in trajectory classes reflecting high levels of co-occurring EBs showed higher levels of general anxiety, separation anxiety, and depressive symptoms across the preschool years. In contrast, children in trajectory classes reflecting single EB manifested higher levels of some, but not all, dimensions of internalizing problems. In addition, their scores varied from one period to another. No sex differences were observed in the above associations. These results underline the need for comprehensive assessments across distinct types of EBs and internalizing problems to better reflect the characteristics that distinguish individual children. Finally, results suggest that children showing early co-occurrent EBs and internalizing symptoms may be an important group to target for in-depth assessment and possibly preventive intervention. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

High-resolution diffusion magnetic resonance imaging and spatial-transcriptomic in developing mouse brain

Brain development is a highly complex process regulated by numerous genes at the molecular and cellular levels. Brain tissue exhibits serial microstructural changes during the development process. High-resolution diffusion magnetic resonance imaging (dMRI) affords a unique opportunity to probe these changes in the developing brain non-destructively. In this study, we acquired multi-shell dMRI datasets at 32 µm isotropic resolution to investigate the tissue microstructure alterations, which we believe to be the highest spatial resolution dMRI datasets obtained for postnatal mouse brains. We adapted the Allen Developing Mouse Brain Atlas (ADMBA) to integrate quantitative MRI metrics and spatial transcriptomics. Diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), and neurite orientation dispersion and density imaging (NODDI) metrics were used to quantify brain development at different postnatal days. We demonstrated that the differential evolutions of fiber orientation distributions contribute to the distinct development patterns in white matter (WM) and gray matter (GM). Furthermore, the genes enriched in the nervous system that regulate brain structure and function were expressed in spatial correlation with age-matched dMRI. This study is the first one providing high-resolution dMRI, including DTI, DKI, and NODDI models, to trace mouse brain microstructural changes in WM and GM during postnatal development. This study also highlighted the genotype-phenotype correlation of spatial transcriptomics and dMRI, which may improve our understanding of brain microstructure changes at the molecular level.

Multidimensional trajectories of Chinese undergraduates’ English speaking self-efficacy: Developmental patterns and influencing factors

This longitudinal study tracked the development of multidimensional English speaking self-efficacy among 335 Chinese college students over one semester, aiming to identify developmental patterns and influencing factors across different dimensions and patterns. Growth Mixture Modeling results revealed distinct patterns of development in different dimensions of English speaking self-efficacy. Regarding self-efficacy for oral tasks, two patterns emerged: “higher initial level with a significant increase” and “lower initial level with a significant increase.” Self-efficacy for complexity showed two patterns as well: “higher initial level with no significant change” and “lower initial level with a significant increase.” Similarly, self-efficacy for self-regulated learning also exhibited two patterns: “higher initial level with an insignificant decrease” and “lower initial level with an insignificant increase.” On the other hand, self-efficacy for accuracy and self-efficacy for fluency displayed a single pattern each, both indicating a “significant increase.” These findings indicate the presence of non-linearity and heterogeneity in the development of English-speaking self-efficacy. Furthermore, the study identified diverse factors that influence the development of English-speaking self-efficacy, including mastery experience, emotional states, and practice, among others. Notably, these influencing factors varied across different dimensions and developmental patterns.

Investigating grey matter volumetric trajectories through the lifespan at the individual level

Adolescents exhibit remarkable heterogeneity in the structural architecture of brain development. However, due to limited large-scale longitudinal neuroimaging studies, existing research has largely focused on population averages, and the neurobiological basis underlying individual heterogeneity remains poorly understood. Here we identify, using the IMAGEN adolescent cohort followed up over 9 years (14–23 y), three groups of adolescents characterized by distinct developmental patterns of whole-brain gray matter volume (GMV). Group 1 show continuously decreasing GMV associated with higher neurocognitive performances than the other two groups during adolescence. Group 2 exhibit a slower rate of GMV decrease and lower neurocognitive performances compared with Group 1, which was associated with epigenetic differences and greater environmental burden. Group 3 show increasing GMV and lower baseline neurocognitive performances due to a genetic variation. Using the UK Biobank, we show these differences may be attenuated in mid-to-late adulthood. Our study reveals clusters of adolescent neurodevelopment based on GMV and the potential long-term impact.

What do measures of gender identity tell us about gender identity over time?

Gender identity is a multifaceted concept and is represented by a wide range of measures and constructs including both self-report and researcher observations of preferences and behaviours. However, despite their similar theoretical underpinning, gender identity measures are rarely found to correlate with one another, and contrasting patterns and trajectories are often found for each construct (Egan & Perry, Developmental Psychology, 37, 2001, 451). Therefore, this systematic review aimed to present a review of the longitudinal research evidence surrounding gender identity development in the absence of formal intervention. Using a systematic search strategy, 21 studies were identified. Narrative synthesis was used to synthesize the data collected in these studies and trajectories were explored for (1) self-identification measures of gender identity, (2) clothing preferences, (3) peer preferences, and (4) object/activity preferences. Overall, the results of this systematic review are consistent with wider research suggesting that distinct developmental patterns can be observed when using different constructs and measures of gender identity.

Serological profiling of pneumococcal proteins reveals unique patterns of acquisition, maintenance and waning of antibodies throughout life.

Streptococcus pneumoniae is a leading cause of morbidity and mortality in children and older adults. Yet knowledge on the development of pneumococcal protein-specific antibody responses throughout life is limited. To investigate this, we measured serum IgG levels to 55 pneumococcal proteins in 11-month old infants (n=73), 24-month old children (n=101), parents (n=99), adults without children <6 years of age (n= 99) and older adults aged >60 years (n=100). Our findings revealed low IgG levels in infancy, with distinct development patterns peaking in adults. A decrease in levels was observed for 27 antigens towards older age. Adults and older adults had increased IgG levels during pneumococcal carriage and at increased exposure risk to S. pneumoniae. Carriage was a stronger predictor than exposure or age for antibody responses. These findings highlight the dynamic nature of naturally acquired humoral immunity to pneumococcal proteins throughout life, offering insights for age-targeted interventions.

The two C. elegans class VI myosins, SPE-15/HUM-3 and HUM-8, share similar motor properties, but have distinct developmental and tissue expression patterns.

Myosins of class VI move toward the minus-end of actin filaments and play vital roles in cellular processes such as endocytosis, autophagy, protein secretion, and the regulation of actin filament dynamics. In contrast to the majority of metazoan organisms examined to date which contain a single MYO6 gene, C. elegans, possesses two MYO6 homologues, SPE-15/HUM-3 and HUM-8. Through a combination of in vitro biochemical/biophysical analysis and cellular assays, we confirmed that both SPE-15/HUM-3 and HUM-8 exhibit reverse directionality, velocities, and ATPase activity similar to human MYO6. Our characterization also revealed that unlike SPE-15/HUM-3, HUM-8 is expressed as two distinct splice isoforms, one with an additional unique 14 amino acid insert in the cargo-binding domain. While lipid and adaptor binding sites are conserved in SPE-15/HUM-3 and HUM-8, this conservation does not enable recruitment to endosomes in mammalian cells. Finally, we performed super-resolution confocal imaging on transgenic worms expressing either mNeonGreen SPE-15/HUM-3 or wrmScarlet HUM-8. Our results show a clear distinction in tissue distribution between SPE-15/HUM-3 and HUM-8. While SPE-15/HUM-3 exhibited specific expression in the gonads and neuronal tissue in the head, HUM-8 was exclusively localized in the intestinal epithelium. Overall, these findings align with the established tissue distributions and localizations of human MYO6.

The political economy of illicit drug crops: forum introduction

ABSTRACT This article and the forum it introduces examine illicit drug crop (IDC) economies from agrarian perspectives. Examining IDCs as a group implies analysing how prohibition distinguishes them from other (licit) crops. We identify seven mechanisms through which prohibition shapes the agrarian political economy of IDCs and explore how these mechanisms and their effects generate distinctive patterns of development and political action amongst ‘illicit peasantries’. We also examine connections between illicit and licit crops, including how licit crop crises and illicit crop booms intertwine. We argue that IDC economies provide a bulwark for smallholders but are by no means peasant idylls.

Developmental expression of catecholamine system in the human placenta and rat fetoplacental unit

Catecholamines norepinephrine and dopamine have been implicated in numerous physiological processes within the central nervous system. Emerging evidence has highlighted the importance of tightly regulated monoamine levels for placental functions and fetal development. However, the complexities of synthesis, release, and regulation of catecholamines in the fetoplacental unit have not been fully unraveled. In this study, we investigated the expression of enzymes and transporters involved in synthesis, degradation, and transport of norepinephrine and dopamine in the human placenta and rat fetoplacental unit. Quantitative PCR and Western blot analyses were performed in early-to-late gestation in humans (first trimester vs. term placenta) and mid-to-late gestation in rats (placenta and fetal brain, intestines, liver, lungs, and heart). In addition, we analyzed the gene expression patterns in isolated primary trophoblast cells from the human placenta and placenta-derived cell lines (HRP-1, BeWo, JEG-3). In both human and rat placentas, the study identifies the presence of only PNMT, COMT, and NET at the mRNA and protein levels, with the expression of PNMT and NET showing gestational age dependency. On the other hand, rat fetal tissues consistently express the catecholamine pathway genes, revealing distinct developmental expression patterns. Lastly, we report significant transcriptional profile variations in different placental cell models, emphasizing the importance of careful model selection for catecholamine metabolism/transport studies. Collectively, integrating findings from humans and rats enhances our understanding of the dynamic regulatory mechanisms that underlie catecholamine dynamics during pregnancy. We identified similar patterns in both species across gestation, suggesting conserved molecular mechanisms and potentially shedding light on shared biological processes influencing placental development.

Distinct developmental patterns in Anopheles stephensi organ systems

Anatomical profiles of insects inform vector biology, comparative development and evolutionary studies with applications in forensics, agriculture and disease control. This study presents a comprehensive, high-resolution developmental profile of Anopheles stephensi, encompassing larval, pupal, and adult stages, obtained through microCT scanning. The results indicate in situ anatomical changes in most organ systems, including the central nervous system, eyes, musculature, alimentary canal, salivary glands, and ovaries, among other organ systems, except for the developing heart. We find significant differences in the mosquito gut, body-wall, and flight muscle development during metamorphosis from other dipterans like Drosophila. Specifically, indirect flight muscle specification and growth can be traced back at least to the 4th instar A. stephensi larvae, as opposed to post-puparial development in other Dipterans like Drosophila and Calliphora. Further, while Drosophila larval body-wall muscles and gut undergo histolysis, changes to these organs during mosquito metamorphosis are less pronounced. These observations, and raw data therein may serve as a reference for studies on the development and the genetics of mosquitoes. Overall, the detailed developmental profile of A. stephensi presented here illuminates the unique anatomy and developmental processes of Culicidae, with important implications for vector biology, disease control, and comparative evolutionary studies.

The value of ecosystem services in arid and semi-arid regions: A multi-scenario analysis of land use simulation in the Kashgar region of Xinjiang

This study aimed to investigate the interrelationships between land use/land cover (LULC) and ecosystem services value (ESV) in arid and semi-arid regions, with a specific focus on the Kashgar region in Xinjiang, China. Four distinct development patterns (BAU, RED, ELP, and EBB) were derived using a multi-objective planning algorithm (MOP), and the relationship between LULC and ESV was analyzed using three methods: the random forest algorithm, the PLUS model, and the ecosystem service equivalence method. The findings indicated a significant projected expansion of LULC in Kashgar by 2030, primarily concentrated in arable and construction land. The ELP scenario demonstrated the lowest growth in cultivated and urbanized land, while the BAU and RED scenarios exhibited higher increments. Notably, the expansion of arable and construction land was concentrated around the urban agglomeration of the Kashgar region, whereas changes in forest land were concentrated near the Kunlun Mountains. Regarding ESV, grassland and watersheds played a significant role, accounting for 45 % and 30 % of the total, grasslands and watersheds emerge as pivotal components in supporting biodiversity, soil preservation, water regulation, and purification. The study underscores the necessity of conserving these ecosystems. This study highlights the trade-offs between economic development and ecological/environmental protection. The RED scenario, driven by rapid economic growth and urbanization, has resulted in a significant decline in ESVs, underscoring the urgency of sustainable land use practices. The MOP-PLUS-ESV model used in this study provides a powerful framework for decision makers to make informed choices in land use planning. By prioritizing a balance between economic development and ecological preservation, the model contributes to sustainable community and regional growth, emphasizing the preservation of important ecosystems. The findings suggest that Kashgar needs to adopt a sustainable land use strategy that balances economic development and ecological/environmental protection to maximize the provision and protection of ESV. The pathway emphasizes the integrated consideration of ESV, rational land use policies, and enhanced ecological protection to achieve an ecological civilization.

Revealing chronic disease progression patterns using Gaussian process for stage inference.

The early stages of chronic disease typically progress slowly, so symptoms are usually only noticed until the disease is advanced. Slow progression and heterogeneous manifestations make it challenging to model the transition from normal to disease status. As patient conditions are only observed at discrete timestamps with varying intervals, an incomplete understanding of disease progression and heterogeneity affects clinical practice and drug development. We developed the Gaussian Process for Stage Inference (GPSI) approach to uncover chronic disease progression patterns and assess the dynamic contribution of clinical features. We tested the ability of the GPSI to reliably stratify synthetic and real-world data for osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), bipolar disorder (BP) in the Adolescent Brain Cognitive Development Study (ABCD), and hepatocellular carcinoma (HCC) in the UTHealth and The Cancer Genome Atlas (TCGA). First, GPSI identified two subgroups of OA based on image features, where these subgroups corresponded to different genotypes, indicating the bone-remodeling and overweight-related pathways. Second, GPSI differentiated BP into two distinct developmental patterns and defined the contribution of specific brain region atrophy from early to advanced disease stages, demonstrating the ability of the GPSI to identify diagnostic subgroups. Third, HCC progression patterns were well reproduced in the two independent UTHealth and TCGA datasets. Our study demonstrated that an unsupervised approach can disentangle temporal and phenotypic heterogeneity and identify population subgroups with common patterns of disease progression. Based on the differences in these features across stages, physicians can better tailor treatment plans and medications to individual patients.

The road to language through gesture

Abstract This study explores the role of gestures in Flemish Sign Language (VGT) development through a longitudinal observation of three deaf children’s early interactions. These children were followed over a period of one and a half year, at the ages of 6, 9, 12, 18 and 24 months. This research compares the communicative development of a deaf child growing up in a deaf family and two deaf children growing up in hearing families. The latter two children received early cochlear implants when they were respectively 10 and 7 months old. It is the first study describing the types and tokens of children’s gestures used in early dyadic interactions in Flanders (Belgium). The description of our observations shows three distinct developmental patterns in terms of the use of gestures and the production of combinations. The study supports the finding that children’s gestural output is subject to their parental language, and it further indicates an impact of age of cochlear implantation.

Determinants of long-term sickness absence trajectories among 19–39-year-old employees with pain

Abstract Background Previous studies have shown higher long-term sickness absence (LTSA) rates among employees with pain as compared to those not reporting pain. We examined distinct developmental patterns in LTSA (≥10 consecutive working days) among young and early midlife employees with pain at baseline, and factors associated with LTSA trajectories. Methods The study population consisted of 19-39-year-old employees (n = 1685) of the City of Helsinki who reported current pain at baseline in 2017. Data on all-cause LTSA days through March 2020 were collected from the Social Insurance Institution of Finland. Group-based trajectory modelling was used to identify distinct all-cause LTSA trajectories. Multinomial logistic regression was used to examine associations of pain characteristics, lifestyle- and occupational factors with trajectory group membership. Results Three distinct LTSA-trajectory groups were identified; No LTSA (74%), Decreasing (18%), and Increasing (8%). Compared to the No LTSA trajectory, employees in the Decreasing trajectory were more likely to have chronic (OR 1.34, 95% CI 1.04-1.73) or multisite (OR 1.81, 95% CI 1.36-2.41) pain, smoke (OR 1.55, 95% CI 1.18-2.03), have obesity (OR 1.70, 95% CI 1.21-2.38), manual or routine non-manual occupation (OR 1.87, 95% CI 1.31-2.67) and high physical workload (OR 1.47, 95% CI 1.14-1.90), after adjusting for age and gender. Predictors of the Increasing trajectory were not identified. Conclusions Distinct LTSA-trajectories were identified among young and early midlife employees with pain, of whom a majority had no LTSA during follow-up. Chronic and multisite pain, unhealthy lifestyle, lower occupational class, and higher physical workload are related to a pattern with more LTSA. Future intervention studies could examine opportunities to prevent LTSA through supporting younger employees who work with pain and have these risk factors. Key messages • Distinct trajectories of LTSA were identified among younger employees with pain, of whom most had no LTSA. Pain characteristics, lifestyle and occupational factors predicted trajectory membership. • Future intervention studies could examine opportunities to prevent LTSA through support to employees who work with pain and have pain-, lifestyle- and occupation related risk factors of LTSA.