Body Size Research Articles

Childhood body size, adulthood adiposity, underlying mechanisms, and risk of incident hypertension: a prospective cohort study of 180,527 participants

BackgroundMechanisms underlying the association of life-course adiposity with incident hypertension in adulthood have not been comprehensively investigated. In this study, we aimed to investigate the potential biochemical and metabolomic mechanisms underlying the association between adiposity and incident hypertension.MethodsA total of 180,527 participants from the UK Biobank aged 37 to 73 years were included. Associations of childhood body size or adulthood adiposity status as well as child–adult weight status change with incident adulthood hypertension were estimated by multivariate Cox proportional regression models.ResultsParticipants with childhood thinner body size and adulthood obesity had the highest risk of incident hypertension (hazard ratio, HR = 3.09, 95% CI = 2.88–3.32) compared with those with “average → normal” pattern, followed by those with “average → obese” pattern (HR = 2.45, 95% CI = 2.31–2.61) and “plumper → obese” pattern (HR = 2.82, 95% CI = 2.62–3.02). Of note, those with “plumper → normal” pattern (HR = 1.11, 95% CI = 1.00–1.23) and “thinner → normal” pattern (HR = 1.17, 95% CI = 1.10–1.24) had the second and third lowest risk of incident hypertension. Adulthood overweight (mediation proportion: 58.7%, 95% CI: 40.4–74.8%) or obesity (mediation proportion = 46.7%, 95% CI: 29.4–64.9%) largely mediated the association between childhood plumper body size and hypertension. The association between adiposity and hypertension was mediated by biochemical indices (e.g., liver function, immunometabolism) and metabolites (e.g., alanine aminotransferase, apolipoprotein A) (mediation proportions ranging from 3.2 to 23.4%).ConclusionsThinner or plumper body size in childhood increases the risk of incident adulthood hypertension, and adulthood adiposity partly mediated this association, suggesting the importance of maintaining normal weight across the life course. Several biochemical indices and metabolites mediated these associations providing clues to underlying biological mechanisms.

Temperature and Moisture Interact to Shape Body Size of Appalachian Salamanders Across Elevation

ABSTRACTAimTo investigate the mechanisms underlying body size variation in Plethodontid salamanders along elevational gradients and to determine the effects of climate variables (elevation, temperature, precipitation, and humidity) on body size.LocationSouthern Appalachian Mountains, USA.TaxonFourteen species of Plethodontid salamanders.MethodsWe used a historical dataset to analyse body size variation across elevation. We assessed the independent effects of elevation, temperature, precipitation, and humidity on body size. To test causal hypotheses regarding these climate variables and their interactions, we built a structural equation model (SEM).ResultsFor 13 of 14 species, we found that body size generally had negative correlations with temperature and precipitation and positive correlations with elevation and humidity, though the strength of the relationships varied. The one remaining species showed different body size patterns in relation to elevation and the three climate variables compared to all other species. Our SEM revealed that precipitation and humidity are the strongest predictors of salamander body size. Body size was not directly impacted by temperature but indirectly through the effects of temperature on humidity levels.Main ConclusionsOur study emphasises the importance of considering both temperature and moisture when examining body size patterns of ectotherms. We found that precipitation, often overlooked, plays a significant role in shaping body size in salamanders, challenging traditional views that focus solely on temperature. These findings highlight the need to integrate multiple, interacting climate variables to better understand organismal traits and to predict responses of organisms to climate change.

Winter Activity and Dormancy of Snails: Freezing and Food Shortage Avoidance Strategy Facing Snow-Cover Shortage

Cold tolerance is a key factor shaping the survival and geographic distribution of terrestrial snails, especially in regions with harsh winters. Understanding how these organisms cope with freezing temperatures is crucial for predicting their responses to changing climates. This study focused on two microsnail species, Vertigo antivertigo and V. moulinsiana, to assess their winter activity, cold tolerance strategies, and whether their body size varies with latitude. Activity patterns were observed under controlled temperatures (0 °C, 2 °C, and 5 °C), while supercooling points (SCP) were measured to evaluate freezing avoidance. Shell morphology was analyzed across populations from various sites in Poland to explore local adaptations. The results showed that snail activity decreases as temperatures drop, with the lowest activity observed at 0 °C. Both species displayed a freezing-avoidant strategy, with V. moulinsiana having slightly higher SCP values, reflecting its adaptation to milder climates. Morphological differences in shell dimensions across sites suggest potential local adaptations to environmental conditions. These findings highlight temperature as a critical driver of activity, survival, and morphological variation in terrestrial snails. Limited winter activity may allow foraging or shelter-seeking but poses risks for overwintering. As climate change leads to snow-free winters, these species may face significant challenges in maintaining their populations and distributions.

Estimating body size in the large carpenter bees (<i>Xylocopa</i>)

Body size is a salient functional trait in bees, with implications for reproductive fitness, pollination ecology, and responses to environmental change. Methods for quantifying bee body size commonly rely on indirect estimates and vary widely across studies, particularly in studies of the large carpenter bees (Xylocopa Latreille) (Apidae: Xylocopinini). We evaluate the robustness of three common body size parameters (intertegular distance, head width, and costal vein length) as predictors of dry body mass within and among 11 species of Xylocopa (and 5 subspecies). We found that all three size measurements provide robust body size estimates, accounting for 92–93% of intraspecific variation in body mass. Within species, however, these measurements were considerably less predictive of body mass, explaining on average only 36.8% (intertegular distance), 57.4% (head width), and 38.8% (costal vein length) of the variation in body mass. We also highlight a novel application of photogrammetry and 3D modeling to estimate surface area and volume across species, and comment on the utility of these methods for body size estimates in Xylocopa and in insects more broadly. These findings provide practical guidelines for body size estimation methods within and among carpenter bee species.

Metabolic Scaling: Exploring the Relation Between Metabolic Rate and Body Size.

We present an alternative to the traditional classroom lecture on the topics of metabolic scaling, allometric relationships between metabolic rate (MR) and body size, and reasons for rejecting Rubner''s surface "law," concepts that students have described as challenging, counterintuitive, and/or mathematical. In groups, students work with published data on MR and body size for species representing all five vertebrate groups. To support the exercise, we developed a worksheet that has students define the concept in their own words, compare different measures of MR, and evaluate plots of MR and mass-specific MR versus body mass for both homeotherms and poikilotherms. Students also attempt to explain why selected species have exceptionally high or low MR values for their body sizes. Student feedback indicated active learning is an effective way to learn the concepts of metabolic scaling and allometric relationships and that the opportunity to work in groups with real data stimulates interest and an appreciation for the importance of metabolic scaling to the understanding of animal physiology.

Reduction in thermal plasticity of life history traits in response to cold selection: an experimental evolution study using Drosophila melanogaster

IntroductionHow selection influences phenotypic plasticity is an important question in evolutionary biology. We report an experimental evolution study that examined how prolonged selection at cold vs. warm temperature impacts the thermal plasticity of traits like reproductive output, body size, and body water content in Drosophila melanogaster.MethodsWe conducted the study on two sets of large, outbred fly populations: one maintained at the standard fly rearing temperature, i.e., 25°C, and another selected at cold temperature, i.e., 17°C, for 3.5 years. Both selection lines were derived from the same ancestral population.Results and discussionWe found that while 25°C selected females lay significantly fewer eggs in cold compared to warm or optimal rearing temperature of 25°C, the 17°C selected females have consistent or canalized fecundity levels across warm and cold conditions. Sustained fecundity levels across cold and warm conditions are potential marks of adaptation to a broader thermal range. While phenotypic plasticity may aid in adaptation to new environments, for traits such as fecundity, consistent levels across environments, that is, low plasticity, may be more adaptive. We also found that male flies from cold vs. warm selection regimes differ in their thermal plasticity. Plasticity of dry weight and body water content was reduced in the cold-selected males, indicating the evolution of canalized levels for these traits too. While canalized fecundity levels across temperatures can potentially help in thermal adaptation, the significance of reduced plasticity of male body size and water content needs to be investigated in the future.

Pollen-Derived Fatty Acids and Amino Acids Mediate Variance in Pollinator Visitation.

Pollinators help maintain functional landscapes and are sensitive to floral nutritional quality. Both proteins and lipids influence pollinator foraging, but the role of individual biochemical components in pollen remains unclear. We conducted an experiment comprising common garden plots of six plant species (Asteraceae, Rosaceae, Onagraceae, Boraginaceae, and Plantaginaceae). These plots were treated with low concentrations of agrochemicals, including fertilizer, herbicide, and a combination of both to induce intra-specific variation in floral chemistry. We recorded insect visitation to inflorescences over two years and eight sites in Dublin, Ireland. We analyzed the pollen amino acid and fatty acid content, quantifying the concentrations of 51 fatty acids and 17 amino acids of the six focal plant species across the four agrochemical treatments. We tested relationships between the pollen composition and the insect visitation matrix as well as an insect trait matrix including sociality, body size, nesting behavior, and whether the insect was a bee or hoverfly. We found: (i) the agrochemical treatments did not affect the biochemical composition of the pollen; (ii) there were many strong associations between fatty acids, amino acids, insect traits, and visitation; and (iii) specific compounds with strong associations (montanic acid, cysteine, and proline) explained more of the variance in insect abundance (honeybees, bumble bees, and hoverflies) than the total amino acid or fatty acid concentrations in the pollen. Our results suggest it is important to evaluate the contribution of individual biochemical compounds in pollen to insect visitation, and also that different insect species respond to different pollen compounds.

Body Fat and Obesity Rates, Cardiovascular Fitness, and the Feasibility of a Low-Intensity Non-Weight-Centric Educational Intervention Among Late Adolescents: Quasi-Experimental Study.

Obesity rates among Saudi adolescents are increasing, with regional variations highlighting the need for tailored interventions. School-based health programs in Saudi Arabia are limited and often emphasize weight and body size, potentially exacerbating body image dissatisfaction. There is limited knowledge on the feasibility of non-weight-centric educational programs in Saudi Arabia and their effects on health behaviors and body image. This study aimed to (1) assess the prevalence of obesity using BMI-for-age z score (BAZ) and fat percentage among Saudi adolescents; (2) evaluate key health behaviors, cardiovascular fitness, and health literacy; and (3) assess the feasibility and impact of a low-intensity, non-weight-centric educational intervention designed to improve knowledge of macronutrients and metabolic diseases, while examining its safety on body image discrepancies. A quasi-experimental, pre-post trial with a parallel, nonequivalent control group design was conducted among 95 adolescents (58 boys and 37 girls; mean age 16.18, SD 0.53 years) from 2 public high schools in Medina City, Saudi Arabia. Participants were randomly assigned to either the weight-neutral Macronutrient + Non-Communicable Diseases Health Education group or the weight-neutral Macronutrient Health Education group. Anthropometry (BAZ and fat percentage), cardiovascular fitness, physical activity, and eating behaviors were measured at baseline. Independent t tests and χ² tests were conducted to compare group differences, and a 2-way mixed ANOVA was used to evaluate the effect of the intervention on macronutrient knowledge and body image discrepancies. A total of 69 participants completed the postintervention assessments. The prevalence of overweight and obesity based on BAZ was 37.9% (36/95), while 50.5% (48/95) of participants were classified as overfat or obese based on fat percentage. Students with normal weight status were significantly more likely to have had prior exposure to health education related to metabolic diseases than students with higher weight status (P=.02). The intervention significantly improved macronutrient-metabolic knowledge (F1,64=23.452; P<.001), with a large effect size (partial η²=0.268). There was no significant change in students' body image from pre- to postintervention (P=.70), supporting the safety of these weight-neutral programs. The intervention demonstrated strong feasibility, with a recruitment rate of 82.6% and a retention rate of 72.6%. This study reveals a high prevalence of obesity among Saudi adolescents, particularly when measured using fat percentage. The significant improvement in knowledge and the nonimpact on body image suggest that a non-weight-centric intervention can foster better health outcomes without exacerbating body image dissatisfaction. Region-specific strategies that prioritize metabolic health and macronutrient education over weight-centric messaging should be considered to address both obesity and body image concerns in adolescents.

Gut microbiota and quantitative traits divergence at different altitude of long-tailed dwarf hamsters, Cricetulus longicaudatus

To investigate the community structure and diversity of gut microflora and their function in body mass regulation, as well as the effects of various locations on gut microbiota and Cricetulus longicaudatus body mass regulation at various elevations. We examined the diversity, abundance, and community structure of the gut microbiota of long-tailed dwarf hamsters from eight regions in Shanxi province during summer using 16S rDNA sequencing technology and analyzed the relationships between these microbiota and environmental variables as well as morphological indicators. The results revealed Firmicutes and Bacteroidetes as the dominant phyla at the phylum level, with Lactobacillus emerging as the predominant genus. We observed differences of gut microflora between different areas, and this diversity is affected by altitude. The high-altitude areas individuals had lower β diversity of gut microbiota than the low-altitude area. Moreover, the body and skull indexes of long-tailed dwarf hamsters also changed with altitude. The result presented in this study indicated that the body size of long-tailed dwarf hamsters conforms to Bergmann's law. And Providencia had significant correlation with body size. Finally, functional analysis of the gut microbiota showed changes in metabolic function that depended on elevation, and collinear network analysis showed how the gut microbiota interacts with each other. All of these results suggest that long-tailed hamsters are different depending on their altitude, with altitude being the main factor affecting both the structure of microbes and the way their metabolism works. This study shows that altitude has a big effect on the gut microbiota and phenotypic traits of long-tailed hamsters. It also shows how well this species can adapt to changes in altitude.

Hydrophobic PU fabric with synergistic conductive networks for boosted high sensitivity, wide linear-range wearable strain sensor

Strain sensing fabrics are able to sense the deformation of the outside world, bringing more accurate and real-time monitoring and feedback to users. However, due to the lack of clear sensing mechanism for high sensitivity and high linearity carbon matrix composites, the preparation of high performance strain sensing fabric weaving is still a major challenge. Here, an elastic polyurethane (PU)-based conductive fabric (GCPU) with high sensitivity, high linearity and good hydrophobicity is prepared by a novel synergistic conductive network strategy. The GCPU fabric consists of graphene sheets (GS)/carbon nanotubes (CNTs) elastic conductive layer and a PU elastic substrate. GS and CNTs can be constructed into a synergistic conductive network, and the fabric is endowed with high conductivity (1.193 S m-1). Simulated equivalent circuits show that GS in the conductive network will break violently under applied strain, making the GCPU fabric extremely sensitive (gauge factor 102). CNTs are spatially distributed in GS lamellae, avoiding the phenomenon that the constructed synergistic conductive network is violently fractured under the applied strain, which leads to the decrease of linearity (0.996). Styrene-ethylene-butylene-styrene (SEBS) was used as a dispersant and binder to uniformly disperse and closely bond GS and CNTs into PU fabrics. In addition, the hydrophobicity of SEBS makes the GCPU fabric resistant to water environment (The contact angle is 123°). Due to the good mechanical stability of GCPU fabric, GCPU fabric has a wide strain range (0%-50%) and high cycle stability (over 1000 cycles). In practice, GCPU fabric can accurately simulate and detect the size and deformation motion of human body. Therefore, the successful construction of elastic fabrics with synergistic conductive networks provides a feasible path for the design and manufacture of wearable intelligent fabrics.

Comparison of Acute and Protracted Gamma Irradiation Effects During Perinatal Development in Beagle Dogs.

Ionizing radiation exposure during perinatal development can produce various biological effects on the developing offspring. These effects are dependent on a number of factors, including total dose, dose rate and the developmental processes occurring at the time of irradiation. The present study conducted an analysis of historical radiobiological archived data involving 60Co-gamma irradiation of beagle dogs at specific periods of prenatal or postnatal development. The original studies were performed at two sites where animals were exposed to a single, acute dose of 0.2 or 1.0 Gy at six different stages of perinatal development or with protracted exposures ranging from 0.004 to 0.35 Gy per day, over multiple days of gestation. A number of outcomes were investigated after perinatal irradiation including changes in sex ratio, survival probability, disease incidence and growth of animals, based on collected size and weight measurements of animals and different tissues. Protracted irradiations with doses up to 0.35 Gy per day did not significantly affect survival in animals when irradiated prenatally, although significant increases in the incidence of neoplasms and diseases related to the cardiovascular and urogenital system were observed at the time of death. Dogs irradiated at a dose rate of 0.10 Gy per day, with the irradiations continuing after birth and resulting in the accumulation of large total doses, were observed to have chronic radiation syndrome symptoms based on pathologies related to the hematopoietic system. Acute irradiation with 0.2 and 1.0 Gy resulted in changes of different body or tissue sizes measured in animals terminally, with changes detected after irradiation at all tested prenatal and postnatal time points, with the exception of irradiation at 365 days after birth. The present analysis provides new information regarding the biological effects of ionizing radiation during perinatal development in offspring in the unique mammalian study model of the beagle dog.

Changes in marine iguana (Amblyrhynchus cristatus) heart rates suggest reduced metabolism during El Niño events

AbstractMarine iguanas occasionally face severe food shortages because of algal dieback during El Niño events. Research on their adaptations to these periods has highlighted their unique ability to shrink in body length, which reduces their energetic needs. Additional mechanisms, like sustaining lower body temperatures and metabolic rates, could potentially also lower energy consumption, but have never been examined. We measured 665 iguanas over an 11‐year period including three El Niño events, and examined how heart rates (a proxy for metabolic rates) and body temperatures change with sea‐surface temperature oscillations (Oceanic Niño Index, ONI). Heart rate (adjusting for body size, temperature, season, and study site) was negatively correlated with ONI and lower during El Niño, whereas the adjusted body temperature did not correlate with ONI or differ between El Niño and other periods. We therefore hypothesize that marine iguanas can depress their metabolic rates in response to the harsh conditions, an adaptation that is complementary to shrinking and may further enhance their survival through periods of limited food. Direct metabolic measurements are needed to test this hypothesis.

Osteology and functional morphology of a transitional pterosaur Dearc sgiathanach from the Middle Jurassic (Bathonian) of Scotland

Pterosaurs were the first vertebrates to evolve active flight. The lack of many well-preserved pterosaur fossils limits our understanding of the functional anatomy and behavior of these flight pioneers, particularly from their early history (Triassic to Middle Jurassic). Here we describe in detail the osteology of an exceptionally preserved Middle Jurassic pterosaur, the holotype of Dearc sgiathanach from the Isle of Skye, Scotland. We identify new autapomorphies of the flight apparatus (humerus and sternum), which further support the distinctiveness of Dearc compared with other early-diverging pterosaurs and describe features, such as the vertebral morphology, shared with later-diverging pterosaurs that probably developed convergently to support a large body size or as a sign of modular evolution. We used extant phylogenetic bracketing to infer the principal cranial and antebrachial musculature, indicating that Dearc had large and anteriorly placed palatal musculature that compensated for weak temporal jaw adductors and wing musculature suggestive of flight style reliant on powerful adduction and protraction of the humerus. Comparisons with other pterosaurs revealed that non-pterodactyloids such as Dearc, despite their overall conservative bauplans, adapted various flight and feeding styles. The osteology and myology of Dearc are indicative of a large predator that flew and hunted above lagoons and nearshore environments of the Middle Jurassic.

Sex-specific growth and morphometric sexing of chicks of the Black-headed Gull (Chroicocephalus ridibundus)

In birds, sexual size dimorphism often becomes evident as early as chicks’ growth stage. A larger sex usually has an advantage in food competition among siblings. In the smaller sex, the lesser ultimate size can be compensated by faster growth or earlier fledging. As a consequence, sex differences can manifest themselves not only in body size but also in the body condition or the rate of weight gain. This phenomenon provides additional opportunities for sexing of chicks by discriminant analysis of growth parameters. Our work deals with the influence of sex on the growth of Black-headed Gull chicks. Using logistic models, we examined growth patterns of 80 males and 76 females from hatching to departure from breeding colonies during three seasons. In males, the total head length, tarsus length, and body mass were greater than those in females from the first days of life and reached large asymptotic values. Tarsus length was a better predictor of sex than head length or body mass was. The sex of chicks did not have a significant effect on global growth rates; however, compared to males, females had a lower body condition (the difference between observed and expected chick body mass) at age 8 days and gained less weight between 21 and 28 days. Using these differences, we developed a discriminant function that allowed to correctly predict the sex of 88.5% of Black-headed Gull chicks before fledging.

Are associations of adulthood overweight and obesity with all-cause mortality, cardiovascular disease, and obesity-related cancer modified by comparative body weight at age 10 years in the UK Biobank study?

Adults living with overweight or obesity do not represent a single homogenous group in terms of mortality and disease risks. The aim of our study was to evaluate how the associations of adulthood overweight and obesity with mortality and incident disease are modified by (i.e., differ according to) self-reported childhood body weight categories. The sample comprised 191,181 men and 242,806 women aged 40-69 years (in 2006-2010) in the UK Biobank. The outcomes were all-cause mortality, incident cardiovascular disease (CVD), and incident obesity-related cancer. Cox proportional hazards regression models were used to estimate how the associations with the outcomes of adulthood weight status (normal weight, overweight, obesity) differed according to perceived body weight at age 10 years (about average, thinner, plumper). To triangulate results using an approach that better accounts for confounding, analyses were repeated using previously developed and validated polygenic risk scores (PRSs) for childhood body weight and adulthood BMI, categorised into three-tier variables using the same proportions as in the observational variables. In both sexes, adulthood obesity was associated with higher hazards of all outcomes. However, the associations of obesity with all-cause mortality and incident CVD were stronger in adults who reported being thinner at 10 years. For example, obesity was associated with a 1.28 (1.21, 1.35) times higher hazard of all-cause mortality in men who reported being an average weight child, but among men who reported being a thinner child this estimate was 1.63 (1.53, 1.75). The ratio between these two estimates was 1.28 (1.17, 1.40). There was also some evidence that the associations of obesity with all-cause mortality and incident CVD were stronger in adults who reported being plumper at 10 years. In genetic analyses, however, there was no evidence that the association of obesity (according to the adult PRS) with mortality or incident CVD differed according to childhood body size (according to the child PRS). For incident obesity-related cancer, the evidence for effect modification was limited and inconsistent between the observational and genetic analyses. Greater risks for all-cause mortality and incident CVD in adults with obesity who perceive themselves to have been a thinner or plumper than average child may be due to confounding and/or recall bias.

The relationship between primate distal fibula trabecular architecture and arboreality, phylogeny and size.

The fibula, despite being traditionally overlooked compared to the femur and the tibia, has recently received attention in primate functional morphology due to its correlation with the degree of arboreality (DOA). Highlighting further fibular features that are associated with arboreal habits would be key to improving palaeobiological inferences in fossil specimens. Here we present the first investigation on the trabecular bone structure of the primate fibula, focusing on the distal epiphysis, across a vast array of species. We collected μCT data on the distal fibula for 21 species of primates, with representatives from most of the orders, and we employed a recently developed approach implemented in the R package 'indianaBones' to isolate the entire trabecular bone underlying an epiphysis or articular facet. After extracting both traditional trabecular parameters and novel topological indices, we tested for the posited relationship between trabecular bone and DOA. To disentangle this effect from others related to body size and phylogenetic relationship, we included a body mass proxy as covariate and employed phylogenetic comparative methods. We ran univariate/multivariate and exploratory/inferential statistical analyses. The trabecular structure of the fibular distal epiphysis in primates does not appear to be associated with the DOA. Instead, it is strongly affected by body mass and phylogenetic relationships. Although we identified some minor trends related to human bipedalism, our findings overall discourage, at this stage, the study of distal fibula trabecular bone to infer arboreal behaviors in extinct primates. We further found that body size distribution is strongly related to phylogeny, an issue preventing us from unravelling the influence of the two factors and that we believe can potentially affect future comparative analyses of primates. Overall, our results add to previous evidence of how trabecular traits show variable correlation with locomotor aspects, size and phylogenetic history across the primate skeleton, thus outlining a complex scenario in which a network of interconnected factors affects the morphological evolution of primates. This work may represent a starting point for future studies, for example, focusing on the effect of human bipedalism on distal fibula trabecular bone, or aiming to better understand the effects of body size and phylogenetic history on primate morphological evolution.

Size-Specific Dose Estimate for Chest of Adult Patients in 128- Slice Computed Tomography at Rajavithi Hospital

Aims: To determine the patient radiation dose using Size-Specific Dose Estimates (SSDEs) for chest CT in adult patients performed with 128-slice CT technology. Study Design: A descriptive cross-sectional study was conducted as a retrospective analysis. Place and Duration of Study: Department of Radiology, Rajavithi Hospital, between April 1 and September 30, 2021. Methods: We included 500 patients (209 males, 291 females). All patients underwent chest contrast enhancement with a venous phase protocol. The patient radiation dose in terms of SSDE was calculated based on AP+Lat dimensions, effective diameter, and water-equivalent diameter. SSDEs was measured from the middle slice of the scan range. The conversion factors following body size and composition were applied according to the AAPM Reports No. 204 and 220 recommendations. Additionally, the study assessed the effective dose and dose-length product (DLP). Key parameters, including DLP, CTDIvol, effective dose, and SSDEs at the 75th percentile, were evaluated to determine radiation dose levels. These values were then compared with established national and international diagnostic reference levels. Results: The study found that the mean DLP was 301.74 mGy·cm, CTDIvol was 8.38 mGy, effective dose was 4.22 mSv, SSDE (AP+Lat) was 11.80 mGy, SSDE (Effective Diameter) was 11.86 mGy, and SSDE (Dw) was 12.91 mGy. When compared with reference radiation dose values from Thailand and international standards, the DLP, CTDIvol, and effective dose values were found to be lower than both Thai and international reference values. In contrast, the SSDE (AP+Lat) was also lower than previously reported findings. Additionally, the study found no available comparative data for SSDE (Effective Diameter) and SSDE (Dw). Conclusion: The comparison of radiation dose values using SSDE across the three methods revealed highly consistent results. The SSDE values obtained from this study can serve as reference levels for the radiation doses received by patients undergoing CT scans at the Radiology Department of Rajavithi Hospital. These values are instrumental in assessing the appropriateness of radiation doses applied during CT imaging and can serve as benchmarks for future dose optimization efforts. Furthermore, this study highlights the significance of evaluating radiation doses in diagnostic imaging, providing valuable baseline data that enhances our understanding of the radiation risks associated with various types of examinations. Further research is warranted to investigate radiation exposure in computed tomography for other body regions.

P0210 ORMDL proteins regulate intestinal epithelial cell homeostasis by modulating ER architecture, autophagy, and DNA damage response

Abstract Background ORM1-like protein 3 (ORMDL3) is a risk gene for asthma and inflammatory bowel disease (IBD), identified in genome-wide association studies (GWAS).1,2 It encodes an endoplasmic reticulum (ER)-resident transmembrane protein implicated in calcium homeostasis, sphingolipid biosynthesis, and regulation of the unfolded protein response (UPR) upon ER stress.3,4 However, the role of ORMDL3 and its homologous protein family members ORMDL1 and ORMDL2, which exhibit partly redundant functions, remains unclear in the context of intestinal inflammation. Methods Constitutive and conditional intestinal epithelial cell-specific knockout (KO) mice for Ormdl1, Ormdl2, and Ormdl3 were generated. Histological analysis of small intestinal (SI) Paneth cells (lysozyme immunohistochemistry), goblet cells (periodic acid-Schiff staining) and ER morphology in Paneth cells (transmission electron microscopy [TEM]) was conducted. Interactions between ORMDL proteins and autophagy-related proteins were examined by co-immunoprecipitation and immunoblot assays in irradiated mouse embryonic fibroblasts (iMEFs). Organoids derived from Ormdl1/2/3ΔIEC mice were used for bulk RNA sequencing. Results The Ormdl1/2/3 triple KO was embryonically lethal, while Ormdl3-KO and Ormdl1/3 double KO mice exhibited reduced body size, weight, and embryonic viability, along with fewer Paneth and goblet cells. To eliminate any compensatory effects of the multiple ORMDL proteins, the Ormdl1/2/3ΔIEC mice were analyzed. These mice showed no macroscopic phenotype but displayed microscopic inflammation, reduced Paneth and goblet cells, and increased SI tuft cells. Both constitutive and conditional Ormdl knockout mice showed massive dilation of the ER. While autophagy is a known compensatory mechanism resolving ER stress, we demonstrated that ORMDL3 co-localized and co-precipitated with the autophagy-related protein LC3 (microtubule-associated protein 1A/1B-light chain 3). Consistent with this, loss of ORMDL proteins compromised autophagic flux. Bulk RNA sequencing of SI organoids from Ormdl1/2/3ΔIEC mice revealed reduced expression of genes involved in lipid biosynthesis, tuft cell differentiation via BMP-signalling, and innate immunity, including antimicrobial peptides, likely due to loss of Paneth cells. In contrast, DNA damage response genes were upregulated, as reflected by an increase in γ-H2AX-positive epithelial cells. Conclusion The data suggest a critical regulatory role for ORMDL proteins in the ER-autophagy axis within epithelial cells, shaping mucosal homeostasis and expression of antimicrobial peptides, thereby conferring protection against IBD. Further studies are required to elucidate the molecular basis of the function of ORMDL proteins in intestinal inflammation.

Left bundle branch area pacing in children – case series

Abstract Background Left bundle branch area pacing (LBBAP) is a new concept that provides physiological pacing with a narrow QRS duration. Recently published data suggest that LBBAP may prevent deleterious effects of right ventricular pacing, namely pacemaker-induced cardiomyopathy, especpecially in patients with expected high ventricular pacing burden, which may be of particular importance in children. Case summary Herein, we report successful implantation of Medtronic SelectSecure (Model 3830, Medtronic Inc.) right ventricle electrode in the region of left bundle branch area in three consecutive children (two 16-year-old and one 8-year-old). Indication for pacemaker implantation was third-degree atrioventricular block in all cases. Implantations were performed under general anaesthesia and there were no acute complications. During the median follow-up of six months, there were no adverse events and the electrical parameters of the device remained stable. Discussion Compared with adult patients, implantation of pacemakers in children may still be challenging, not only because of smaller body size but also due to continuing growth and a higher rate of lead and device-related complications. We have demonstrated that implantation of LBBAP in children is feasible and could be worth considering, particularly in patients with expected high ventricular pacing burden. Further studies are needed to assess the efficacy and safety of left bundle branch area pacing in children during long-term observation.

The Black Sea Pleurobrachia (Ctenophora): P. rhodopis or P. pileus?

Pleurobrachia Fleming, 1822 is the native taxon of ctenophores in the Black Sea. Until now, its species affiliation has not been resolved: the Black Sea Pleurobrachia is referred to either P. pileus (O.F. Müller, 1776) or P. rhodopis (Chun, 1879). In the taxonomic reviews, both species are recognised as occurring in the Black Sea. The experts on zooplankton identified the Black Sea Pleurobrachia based solely on its definitive body size, but size cannot be a sufficient diagnostic feature. To clarify the species identity of the Black Sea Pleurobrachia, we carried out a phylogenetic analysis using the nucleotide sequences of the mitochondrial COI and the nuclear 18S rRNA gene fragments. As a result, we have established that the Black Sea Pleurobrachia is P. pileus and its identification as P. rhodopis in the global taxonomic databases is erroneous.